Aging & Mental Health Subthreshold depression ...

This article was downloaded by: [Adams, Kathryn Betts] On: 23 March 2010 Access details: Access Details: [subscription number 916358882] Publisher Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 3741 Mortimer Street, London W1T 3JH, UK

Aging & Mental Health

Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713404778

Subthreshold depression: Characteristics and risk factors among vulnerable elders Kathryn Betts Adams a;Heehyul Moon a a Mandel School of Applied Social Sciences, Case Western Reserve University, Cleveland, OH 441067164, USA

To cite this Article Adams, Kathryn Betts andMoon, Heehyul(2009) 'Subthreshold depression: Characteristics and risk

factors among vulnerable elders', Aging & Mental Health, 13: 5, 682 — 692 To link to this Article: DOI: 10.1080/13607860902774501 URL: http://dx.doi.org/10.1080/13607860902774501

PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

Aging & Mental Health Vol. 13, No. 5, September 2009, 682–692

Subthreshold depression: Characteristics and risk factors among vulnerable elders Kathryn Betts Adams* and Heehyul Moon Mandel School of Applied Social Sciences, Case Western Reserve University, Cleveland, OH 44106-7164, USA

Downloaded By: [Adams, Kathryn Betts] At: 00:00 23 March 2010

(Received 20 November 2008; final version received 13 January 2009) Objectives: This study examines symptoms of subthreshold depression among older adults in congregate housing, compared with their nondepressed peers, and tests a conceptual model of subthreshold depression. Hypotheses included that subthreshold depression would be characterized and distinguished by low energy, social withdrawal, and depletion, rather than sadness, and that subthreshold depressed elders would be distinguished by poorer health and functioning, loneliness, and grieving a recent loss. Method: A self-administered survey was followed by a diagnostic interview by telephone to (N ¼ 166) white and African-American residents of independent and assisted living apartments from six retirement communities, average age 82.9 years. The Mini International Neuropsychiatric Interview (MINI) determined depression status. The 30-item Geriatric Depression Scale was used to measure symptoms. Results: Forty-six individuals (27.7%) were identified as subthreshold depressed, seven as suffering from major depression, and 113 as non-depressed. Subthreshold depression was characterized by low energy, difficulty with initiative, worries about the future, lack of positive affect, sadness and irritability. Negative affect symptoms such as sadness and irritability best discriminated the subthreshold group from the nondepressed. Risk factors for subthreshold depression in this sample included less education, lower socio-economic status, African-American race, grieving, and social loneliness. Conclusion: Subthreshold depression in this group of residents of congregate housing was similar to the depletion experienced by many nondepressed elders, but further characterized by negative affect and lack of hope for the future. Social factors, such as socioeconomic status and personal losses, constituted greater risks for subthreshold depression than did health and functioning. Keywords: non-major depression; subthreshold depression; Geriatric Depression Scale; MINI; independent living; assisted living

Introduction The topic of depression in late life has received considerable attention in the literature, capturing the interest of researchers and health and social service providers. Depression is the most frequently diagnosed mental disorder among older adults (Blazer, 2003). Although major depressive disorder is more common in young or middle adulthood, subthreshold depression – depressive symptoms which do not meet criteria for Major Depressive Episode or other specific depressive disorders – is estimated to be more common in late adulthood (Gallo & Leibowitz, 1999), reportedly affecting up to 5 million older adults (NIMH, 2007), with recent prevalence estimates of 18% in the community and 10%–23% among medically-ill elders (Judd & Akiskal, 2002). Studies suggest that the prevalence of subthreshold depressive symptoms increases in old age, and is quite high among residents of senior congregate housing (Lavretsky & Kumar, 2002), who tend to be older and more physically frail than elders remaining in the community. Subthreshold depression has been shown to be associated with significant functional impairments (Blazer, 2003; Gallo, Rebok, Tennstedt, Wadley & Horgas, 2003; Lyness, King, Cox, Yoediono, & Caine, 1999; Seidlitz, Lyness, Conwell, Duberstein, *Corresponding author. Email: [email protected] ISSN 1360–7863 print/ISSN 1364–6915 online ß 2009 Taylor & Francis DOI: 10.1080/13607860902774501 http://www.informaworld.com

& Cox, 2001) and risk for future major depressive episode (Chopra et al., 2005). While precise definitions of subthreshold depression vary, many studies have found these subsyndromal depressive symptoms to be associated with subjective distress and reduced quality of life in older adults (Lavretsky & Kumar, 2002), and appropriate targets for non-pharmacological intervention approaches (Rabheru, 2004). There is a disagreement in the literature about whether subthreshold depression constitutes a qualitatively distinct syndrome in older adults or a set of fewer depressive symptoms along a continuum. Clinical validation of the subthreshold category of depression in adults of all ages in primary care has likened it to neurotic or existential depression, therefore suggesting it to be qualitatively different from major depression (Akiskal, Judd, Gillin, & Lemmi, 1997). Other researchers have noted that late life subthreshold depressive symptoms present in various combinations that differ from the usual DSM-IV criteria (Geiselmann & Bauer, 2000; Kumar, Lavretsky, & ElderkinThompson, 2004) and that symptoms tend to be somatic, rather than emotional (Judd & Akiskal, 2002). Geiselmann and Bauer (2000), analyzing data from the Berlin Study on Aging, found that symptom profiles of older adults with subthreshold depression


Aging & Mental Health resembled the profiles of nondepressed elders more than they resembled the profiles of those with major depression, with low proportions of symptoms of insomnia, suicidal thinking, and feelings of guilt or worthlessness. However, they also found subthreshold depressed elders resembled those with criterion depression in proportion of other symptoms and characteristics, including poor concentration, low energy, recent crying, number of somatic diagnoses, and use of psychotropic medications (Geiselmann & Bauer, 2000; Geiselmann, Linden, & Helmchen, 2001). Others have suggested that subthreshold depression is a quantitatively lesser version of Major Depressive Disorder, rather than a distinct entity (Lewinsohn, Solomon, Seeley, & Zeiss, 2000; Royall, 2004). In keeping with a hypothesis that subthreshold depression may represent a qualitatively different syndrome from major depression, we should find specific symptoms over-represented among those with subthreshold depression. In older adults, a specific syndrome variously referred to as ‘depression without sadness’ (Gallo & Rabins, 1999), apathetic depression (Gallo, 2004), or ‘depletion’ (Adams, 2001; Newman, Klein, Jensen, & Essex, 1996) – a set of symptoms more common in older than younger adults that resemble and overlap with what we normally think of as depression – may be a likely candidate for a subthreshold depression syndrome, with its suggestion of fewer and possibly less severe, symptoms. In studies by Gallo Anthony and Muthen (1994) and Gallo, Rabins, Lyketsos, Tien, and Anthony (1997), this nondysphoric depression was found to be more consistent with minor depression than major depression, and was associated with clinically significant functional impairment that contributes to lower quality of life.

Risk factors for subthreshold depression Most of the literature about risk factors for late life depression comes from studies involving major depression or depressive symptoms obtained from screening scales. Studies focused specifically on risk factors for subthreshold depression among older adults have found subthreshold depression to be influenced by the degree of functional disability and the experience of negative life events (Beekman et al., 1997; Fiske, Gatz, & Pedersen, 2003; Horowitz, Reinhardt, & Kenny, 2005). Beyond that, a number of other individual characteristics and social factors are presumed to influence depression in older adults, with unknown effects with regard to subthreshold depression. Health status and disability are among the known risk factors for depression in late life (Cole & Dendukuri, 2003) and some have found these influence minor forms of depression more than major depressive episode (Schoevers et al., 2000). Experience of pain is a related issue that has been linked with geriatric depression (Parmelee, Harralson, Smith, & Schumacher, 2007; Parmelee, Katz, & Lawton, 1991).

683

Loneliness is often a precursor to depression among older adults (Blazer, 2002). Common agerelated losses and transitions, such as moving to a new residence or a change in health that necessitate a change in routine may also promote loneliness. In a review of 149 studies examining loneliness in older persons, women, those over 80, and those with lower incomes, were more likely to be lonely (Pinquart & Sorenson, 2001). For older adults in congregate living or long-term care facilities, attendance at organized social activities does not appear to adequately inoculate against loneliness (Adams, Sanders & Auth, 2004). Further, recent research has suggested that older adults may define depression as loneliness since it is less stigmatizing (Barg et al., 2006). Because loneliness is a known risk factor for depression, it is likely also associated with subthreshold depression. Commonly occurring losses in later life include the death of loved ones, decline in health, losses of customary social roles and perhaps their status and prestige, and, for some, loss of aspects of independent functioning. The grief inherent in bereavement or loss of independent functioning places older adults at risk for both loneliness and depression (Adams, Sanders & Auth, 2004). Symptoms of grief and depression overlap considerably and there is research to suggest that bereavement in older adults poses a substantial risk for major or subthreshold depression (Turvey, Carney, Arndt, Wallace, & Herzog, 1999). Cognitive impairment in older adults is another potential risk factor for psychiatric symptoms, including both depression and anxiety (Chan, Kasper, Black, & Rabins, 2003). The diagnosis of mild cognitive impairment (MCI) has become more widely used in the past few years, and researchers are finding it associated with higher rates of psychiatric symptoms than normal cognitive status (Forsell, Palmer, & Fratiglioni, 2003). Moreover, qualitative studies have found that some people with early-stage cognitive impairment experience a sense of inadequacy and low self-esteem (Clare, 2003; Holst & Holberg, 2003). Impaired cognitive functioning is another important factor to examine in relation to subthreshold depression. The current study identified characteristics and selfreported symptoms of subthreshold depression, and risk factors for subthreshold depression among elders in congregate living facilities. A diagnostic interview conducted by telephone identified these participants as nondepressed, subthreshold depressed, or with major depression. This study focused only on the nondepressed and those with subthreshold depression, testing three related hypotheses: (1) Subthreshold depression will resemble ‘depression without sadness’ or depletion, as represented by a high proportion of withdrawal, apathy, and [lack of] vigor (WAV) endorsement, compared to negative affect endorsement. (2) Subthreshold depressed older adults will be distinguished from those who are nondepressed by differences in demographic and health characteristics, adding validity to this diagnostic category. (3) A

684

K.B. Adams and H. Moon

conceptual model consisting of demographic variables (age, gender, race, marital status, education level, and income adequacy); health (self-rating of health, pain rating, cognitive functioning, and functioning in Instrumental Activities of Daily Living (IADL)); and psychosocial factors (social and emotional loneliness, and grief from a recent loss) will predict subthreshold depression compared to nondepression with a high degree of accuracy.


Methods Procedures and participants The study obtained approval of the Case Western Reserve University IRB Committee and review personnel at each hosting facility. Self-administered surveys of residents in the independent living or assisted living sections of six Continuing Care Retirement facilities with a total population of approximately 1500 residents. The six facilities included three nonprofit (one Jewish, one primarily African-American) and three for-profit independent living or assisted living facilities in Northeast Ohio. Adams visited five out of the six facilities and announced the study to resident groups. In addition, signs were posted and one-page flyers were placed in residents’ open mail cubbies. Blank survey packets with self-addressed stamped envelopes were left in a labeled box near residents’ mailboxes in each facility. Returned surveys had an area for respondents to write their name and contact information to be contacted for a telephone follow-up. Completed surveys were followed by telephone interviews to administer a cognitive screen and depression and anxiety modules of a structured interview based on official diagnostic criteria. Three research assistants, one B.A. level and two M.A. level, with clinical or research experience in social work or psychology, were trained by the Principle Investigator to administer the telephone interviews. A $20 gift card was given to participants completing both the survey and the follow-up. Measures The major depressive episode module of the Mini International Neuropsychiatric Interview (MINI) (Sheehan et al., 1998) was administered over the phone to classify respondents with depression and subthreshold depression. Based on diagnostic criteria from the DSM-IV and ICD-9, the MINI consists of a number of modules that can be administered separately or together. The MINI has been used in a number of studies with primary care patients and older adults, with validity and reliability comparing favorably with longer diagnostic interviews such as the Composite International Diagnostic Interview (CIDI) or the Structured Clinical Interview for DSM Disorders (SCID) (Haringsma, Engels, Beekman, & Spinhoven, 2004; Shvartzman et al., 2005). Modules of the MINI have been administered by phone in at

least two published studies with adult participants (Olfson et al., 1996; Shvartzman et al., 2005). In this study, MINI modules were administered with modified instructions to ask all questions of each participant, rather than stopping if criterion from key symptoms (low mood or loss of interest) was not reached. Respondents in the current study were classified using the 9-item depression module from the MINI as either Major Depressive Episode (5 or more symptoms, including one of the key symptoms), Subthreshold Depressive Symptoms (2–4 symptoms, may or may not include a key symptom), or Nondepressed (0–1 symptoms). The 2-week symptom criterion was retained in this classification. This definition of subthreshold depression that does not require one of the two key symptoms of depression has been used by some of the earliest investigators of this phenomenon (Judd, Akiskal, & Paulus, 1997; Kumar, Lavretsky & Elderkin-Thompson, 2002), and may be termed as subthreshold symptoms (Haringsma et al., 2004). Other investigators have required one of the two key symptoms in defining subthreshold depression (e.g., Olfson et al., 1996); however, one or both key symptoms with the addition or one or two additional symptoms but short of criterion for a diagnosis of major depressive episode has recently received the provisional diagnosis of Minor Depression in the DSM-IV-TR (American Psychiatric Association, 2000) (Rapaport et al., 2002). Thus, the subthreshold depression category here includes both those with Minor Depression (2–4 symptoms inclusive of one of the key symptoms) and subthreshold depression (2–4 symptoms without one of the key symptoms). The other instrument administered by phone was the Modified Telephone Interview for Cognitive Status (TICS-M; Welsh, Breitner, & Magruderhabib, 1993), a cognitive screening measure modeled after the MiniMental State Exam (MMSE) (Folstein, Folstein, & McHugh, 1975), but specifically designed as a phone measure. The TICS-M tests functioning in several domains: concentration, orientation, memory, naming, comprehension, and abstraction. Its validity as a measure of global functioning has been established by high correlation with the MMSE (Welsh et al., 1993). The Geriatric Depression Scale (GDS) (Brink et al., 1982), a 30-item self-rated questionnaire with yes/no responses, was included in the self-administered survey. In the original study introducing this scale, it obtained Cronbach’s alpha for internal consistency of 0.94, test–retest reliability of 0.85, and split-half reliability of 0.94 (Yesavage et al., 1983). Using the 30 items as a single additive scale at one point each for the ‘depressed’ responses, there are several possible cut-off scores for the GDS to distinguish depressed from nondepressed respondents. The original authors recommended the use of 11 points and above, with an obtained sensitivity of 84% and specificity of 95%. A 14-point cut-off has also been referred to in the literature (Kafonek et al., 1989; Lyons, Strain, Hammer, Ackerman, & Fulop, 1989). Most recently,

685


Aging & Mental Health Lavretsky and Kumar (2002) recommended a 12-point cut-off on the GDS as one criterion for clinically significant non-major depression, but Watson and colleagues (2004) determined a lower GDS cut-off of 9 points was appropriate for a sample of oldest-old retirement community residents. Adams and colleagues (Adams, 2001; Adams, Matto, & Sanders, 2004) identified a 6-item WAV factor of the GDS in two samples of older adults, using principal component analysis and confirmatory factor analysis. WAV items describe low energy, preference for staying home, and lack of motivation to start new projects. High scorers on WAV were found to be older, in poorer health, and with greater functional impairment, suggesting that the WAV items describe a depletion syndrome (Adams, 2001). Recently, the WAV symptom cluster and the other GDS factors were validated with a sample of the Chinese older outpatients in Hong Kong (Cheng & Chan, 2007). In the current study, Cronbach’s alpha internal reliability coefficients were run on the six GDS subscales previously identified (Adams et al., 2004), using only nonmissing data for the sample as a whole. The 9-item Dysphoria subscale with its Cronbach alpha of 0.775 fared the best. None of the items, if omitted, would raise that alpha, suggesting good internal consistency for the entire set. The 6-item WAV subscale obtained an alpha of 0.626, which would rise to 0.632 if item #28, Prefer to avoid social gatherings, were omitted. The other preliminary GDS subscales (Hopelessness, Worry, Cognitive, and Agitation) had alpha coefficients of less than 0.6. Health variables in the self-administered survey included Self-Rated Health from the SF-12, with ratings from 1 ¼ Poor to 5 ¼ Excellent, and a pain rating question, also from the SF-12, on which higher scores meant more curtailment of normal activities due to pain. The OARS IADL instrument (Duke University Center for the Study of Aging and Human Development, 1978) was used to indicate functional impairment, with higher scores indicating better functioning. A checklist of 11 chronic health conditions was also included. Additional psychosocial variables in the survey were the DeJong-Gierveld Loneliness Scale (De JongGierveld & Van Tilberg, 1999), with subscales identified by the authors for Social and Emotional Loneliness. This instrument features 12 dichotomous items, so that scores range from 0 to 12, with higher scores meaning more loneliness. Further, we had a yes/ no question about grieving an important loss, which could include any loss, but specifically listed loss of a spouse, other family member or friend, loss of a pet, or a health-related loss. Demographic variables included age in years, gender, a dichotomous education variable: high school or less versus beyond high school, marital status (having a partner versus not), and a perceived income adequacy question that was divided into either plenty/adequate or barely adequate/ inadequate.

Analytic strategies To address our major research questions and hypotheses, we first focused on characteristics of the older adults identified as subthreshold depressed. To determine whether there was a specific symptom cluster that was more commonly represented among the subthreshold depressed individuals, we planned paired t-tests to identify mean differences between the subscales of the GDS. We compared symptoms and characteristics with the nondepressed elders in our study with independent t-tests or Chi-square tests, as appropriate for the type of variable. Mindful of the risks for inflated type I error rates with multiple comparisons, we utilized Bonferroni correction that adjusts the alpha level for these tests. Although this correction is straightforward, it is quite restrictive and may under-estimate actual differences (Sokal & Rohlf, 1995). For instance, Bonferroni reduces the alpha level from 0.05 to 0.0017 for 30 comparisons. We consider results both with and without this correction. Many respondents left from one to four items blank in the GDS. In creation of GDS subscale and total scores, to retain all cases, missing items were replaced by the sample mean for the item, providing a participant missed 20% or fewer items. This imputation strategy results in standard errors of the mean that are attenuated, but checks on our results with and without imputing missing data revealed no substantive differences. We constructed a theoretical model of subthreshold depression consisting of demographic variables (age, gender, race, marital status, education level, and income adequacy), health (pain rating, IADL functioning, self-rated health, and TICS-M total cognitive functioning score), and psychosocial factors (social and emotional loneliness scores, and grief from a recent loss) (Figure 1). Bivariate logistic regression analysis with subthreshold depressed versus nondepressed status as the dependent variable was conducted to test this model. First, we examined bivariate correlations for each pair of independent variables. The only

Demographics: age, gender, race, maritalstatus, education, income

Health: pain, self-rated health, IADL, cognitive status

Subthreshold depression

Psychosocial factors: social /emotional loneliness, grieving an important loss

Figure 1. Conceptual model of subthreshold depression in relation to nondepression.

686


pairs showing any multi-collinearity were the correlations between African-American race and income inadequacy and between pain rating and self-rated health, each with bivariate correlations from 0.5 to 0.6, but not large enough to require eliminating variables on that basis (Pett, Lackey, & Sullivan, 2003). The full model proved to include several nonsignificant predictors. We then refined the model by removing variables with the weakest association to the outcome and evaluated results of the classification tables and goodness-of-fit tests.

needing ‘some help’ with housework, around 30–35% needing some help with travel, shopping, meal preparation, 15% with handling finances, and 6% with taking medications. For personal Activities of Daily Living (ADLs), only 8% reported the need for help with bathing and 3% with dressing or bathroom chores. Overall mean total score on the GDS was 6.44 (4.9), with a range from 0 to 23 points.

Divisions according to MINI depression scores According to participants’ MINI responses, 46 (27.7%) met criteria for subthreshold or minor depression and seven (4.2%) for major depressive episode. The MINI depressive symptoms most frequently reported by the subthreshold group were tiredness/low energy, sleep difficulty (the question includes insomnia and early morning awakening), and less interest and enjoyment in the last 2 weeks, followed by appetite disturbance or weight change, and moving or talking more slowly (Table 1). Of this subthreshold group, 21 (45.6%) endorsed either the low interest or depressed mood item, along with additional symptoms, meeting criterion for Minor Depression.


Results Description of the sample Surveys were returned by 178 participants, of whom 166 gave contact information and were reached for telephone interviews; these complete cases comprise the full sample for this study. The sample of 166 was 22.9% African-American and 77.1% white; 78.3% were female and 81.2% were not married or living with a significant other. The average age for this sample was 82.9 (7.12), with over two-thirds of them 80 years or older. Over 80% were high school graduates, and 51.8% were college graduates or beyond. Of the 146 respondents who indicated a religious preference, 47.9% were Protestant, 28.1% Jewish, and 8.2% Catholic, with the remainder indicating ‘Other’, or ‘None’. On a measure of income adequacy, 36 respondents, 22.1%, reported having just enough to get by or not enough to get by, while the majority of respondents reported having enough or more than enough money. Respondents reported an average of nearly two chronic health conditions from a list of 11, and rated themselves as just above ‘good’ for their health. On the TICS-M, using norms adjusted by level of education, 47 individuals (28.3%) had scores suggestive of mild cognitive impairment. Out of a possible 50 points for correct responses, the group mean was 31.6 (5.6), with a range from 14 to 47. Functional impairments were more commonly seen in IADLs, with 60%

Characteristics of subthreshold depressed group and group differences Table 2 displays comparative demographic and psychosocial characteristics for the subthreshold and nondepressed groups, as defined by their MINI scores; the seven respondents with criterion depression were not included. Chi-square and student t-tests were performed to identify between-group differences. These bivariate tests revealed that the subthreshold depression group consisted disproportionately of those with less education and those who reported inadequate income. The two groups did not differ in gender distribution or age in years, nor did the difference in proportion of African-American elders reach significance. Those with subthreshold depression did not

Table 1. Depressive symptoms endorsed on the telephone-administered MINI for full sample (N ¼ 166) and for those with subthreshold depression (N ¼ 46) and major depressive episode (N ¼ 7). Full sample

Key symptoms: Depressed most of the time, past 2 weeks Less interest or less enjoyment, past 2 weeks Additional symptoms, past 2 weeks: Change in appetite or weight loss Difficulty sleeping or waking too early Moving or talking more slowly Tired/low energy Feeling worthless or guilty Difficulty concentrating or making decisions Considering hurting self, wish to be dead

Subthreshold group

Depression group

N

(%)

N

(%)

N

(%)

14 24

(8.4) (14.5)

7 18

(15.2) (39.1)

6 5

(85.7) (71.4)

21 49 22 48 6 7 6

(12.7) (29.5) (13.3) (28.9) (3.6) (4.2) (3.6)

16 24 16 27 3 4 2

(34.8) (52.2) (34.8) (58.7) (6.5) (8.7) (4.3)

4 6 4 6 3 3 3

(57.1) (85.7) (57.1) (85.7) (42.9) (42.9) (42.9)

687

Aging & Mental Health Table 2. Demographics health conditions, and GDS scores by MINI depression group. Nondepressed (N ¼ 113)

Subthreshold (N ¼ 46)

N (%)

N (%)

Categorical variables Gender: Female Race: African-American Education: HS or less Unmarried Income inadequate Grieving important loss


Continuous variables Age in years # of health conditions Self-rated health (1–5) Pain rating IADL functioning TICS-M cognitive score Emotional loneliness score Social loneliness score GDS dysphoria GDS WAV GDS hopelessness GDS worry GDS cognitive GDS agitation GDS total score

86 21 31 87 15 17

(76.1) (18.6) (27.7) (77.0) (13.5) (16.0)

Mean (SD) 82.8 (7.4) 1.7 (1.2) 3.3 (1.01) 2.1 (1.06) 11.9 (2.07) 32.3 (6.0) 1.4 (1.7) 1.5 (1.7) 0.73 (1.36) 2.41 (1.76) 0.35 (0.74) 0.40 (0.77) 0.93 (1.03) 0.39 (0.66) 5.20 (4.25)

37 13 22 42 17 15

(80.4) (28.3) (48.9) (91.3) (37.0) (34.1)

Mean (SD) 83.7 (7.5) 1.8 (1.3) 1.9 (1.09) 2.5 (1.20) 11.6 (2.08) 30.1 (5.4) 2.1 (2.0) 2.3 (2.0) 1.95 (1.96) 2.85 (1.34) 0.84 (0.85) 0.87 (1.07) 1.27 (1.24) 0.86 (0.79) 8.63 (4.97)

2

p-Value

0.350 1.821 6.458* 4.375* 11.014** 6.038*

0.554 0.177 0.011 0.036 0.001 0.014

t

p-Value

0.736 0.636 2.433* 2.322* 0.412 2.131* 2.348* 2.589* 3.869** 1.708 3.436** 2.721* 1.644 3.883** 4.116**

0.463 0.526 0.016 0.022 0.412 0.035 0.020 0.006 50.0001 0.129 50.0001 0.002 0.077 50.0001 50.0001

Notes: *p 5 0.01, **p 5 0.001 (Bonferroni correction for 14 comparisons, alpha 0.0035). GDS ¼ Geriatric Depression Scale, WAV ¼ Withdrawal, apathy, [lack of] vigor.

differ in IADL functioning or number of health conditions endorsed, but they could be characterized as more likely to be cognitive impaired, with lower selfrated health and higher pain rating. The subthreshold depressed elders were more likely to report grieving a recent loss and had higher loneliness scores. Mean GDS total score for the subthreshold group was 8.63, and for the nondepressed group was 5.20 (t ¼ 4.116, p 5 0.001) (Also see Table 2). The subthreshold group did not have uniformly high GDS total scores; only about 24% of them scored above the cut-off of 12 suggested for subthreshold depression by Lavretsky and Kumar (2002), while 43.5% scored above the cut-off of 9 suggested by Watson et al. (2004). The subthreshold group’s highest GDS factor score was WAV, which was significantly different from the next highest factor score, Dysphoria (paired t ¼ 3.064, df ¼ 45, p ¼ 0.004). Among the GDS factor scores, Dysphoria, Hopelessness, Worry, and Agitation were significantly higher for the subthreshold group than for the nondepressed group. The subthreshold depressed group’s mean WAV score and cognitive score did not differ significantly from those of the nondepressed group.

Depressive symptoms reported by subthreshold depressed and nondepressed We examined endorsement rates for the 30 individual GDS items for the subthreshold group to determine

which specific symptoms were reported (Table 3). The most prevalent depressive symptoms from the GDS reported by the respondents with subthreshold depression were low energy, lack of positive affect or apathy (not finding life exciting) and cognitive changes or confusion (mind not as clear as it used to be), affecting from 50 to 75% of the group. Next most common, over 40% of the group reported difficulties with taking initiative (hard to start new projects), giving up usual activities and interests, and two sentiments about the future, being worried and not being hopeful. The latter, again, also reflects lack of positive affect. And finally, close to one-third of the group reported symptoms of sadness and irritability (downhearted and blue, frequently upset, often feel like crying), preference for staying at home, often get bored, not easy to make decisions, and avoiding social gatherings. In sum, subthreshold depression in this study was characterized by symptoms of apathy, perceived cognitive changes or confusion, lack of positive affect, difficulty taking initiative, worries and lack of hope about the future, sadness, and social withdrawal. We conducted Chi-square tests on each item to compare GDS symptom endorsement for the nondepressed and subthreshold depressed groups. The following items differentiated the nondepressed from the subthreshold group, after Bonferroni correction for multiple tests: Downhearted and blue, [Not] Basically satisfied with life, Often feel like crying, Worry about the future, [Not] Hopeful about the future, and

688


Table 3. Geriatric depression scale items proportion endorsement in the depressed direction, by MINI depression group.


Number endorsed (Percent of nonmissing items) Nondepressed

Subthreshold

Item/Wording

(N ¼ 113)

(N ¼ 46)

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.

8 (7.1) 48 (44.0) 4 (3.6) 15 (13.3) 17 (15.7) 15 (13.6) 5 (4.4) 11 (9.7) 11 (10.0) 10 (8.8) 9 (8.3) 43 (39.4) 13 (12.1) 12 (11.1) 14 (12.6) 10 (8.8) 5 (4.5) 4 (3.6) 44 (39.6) 29 (26.6) 68 (63.6) 6 (5.3) 6 (5.4) 18 (16.2) 8 (7.2) 13 (11.8) 15 (13.6) 30 (26.8) 21 (19.1) 56 (50.5)

10 (21.7) 22 (48.9) 6 (13.3) 13 (28.9) 18 (40.9) 9 (20.5) 5 (10.9) 7 (15.6) 10 (22.2) 9 (20.0) 8 (18.2) 16 (35.6) 18 (40.9) 7 (15.6) 8 (17.8) 17 (37.0) 7 (15.6) 5 (11.1) 22 (52.4) 21 (45.7) 33 (75.0) 4 (8.7) 6 (13.0) 17 (37.8) 15 (32.6) 12 (26.1) 14 (30.4) 13 (28.3) 13 (28.9) 26 (56.5)

Satisfied with life (rev) Dropped activities, interests Feel life is empty Often get bored Hopeful about the future (rev) Bothered by thoughts In good spirits (rev) Afraid something bad will happen Happy most of the time (rev) Often feel helpless Restless and fidgety Prefer to stay at home (rev) Worry about the future More problems with memory Wonderful to be alive (rev) Downhearted and blue Feel pretty worthless Worry a lot about the past Find life very exciting (rev) Hard to start new projects Full of energy (rev) Feel situation is hopeless Most people are better off Frequently get upset Often feel like crying Trouble concentrating Enjoy getting up in AM (rev) Avoid social gatherings Easy to make decisions (rev) Mind as clear as used to be (rev)

Pearson’s 2 ( p-value) 6.88 0.30 5.13 5.38 11.17 1.11 2.26 1.08 4.07 3.78 3.13 0.20 15.81 0.58 0.71 18.32 5.59 3.38 2.02 5.37 1.85 0.64 2.69 8.55 16.78 4.91 6.05 0.04 1.79 0.48

(0.009)** (0.582) (0.024)* (0.020)* (0.001)** (0.292) (0.133) (0.299) (0.044)* (0.052) (0.077) (0.651) (0.001)** (0.448) (0.401) (0.001)** (0.018)* (0.066) (0.156) (0.020)* (0.174) (0.425) (0.101) (0.003)** (0.001)** (0.027)* (0.014)* (0.850) (0.181) (0.488)

Notes: Only nonmissing data were included for these item analyses, so N’s are not equal. **Indicates significant difference between subthreshold depression group and nondepressed group using Bonferroni correction, alpha 0.0017. *Indicates alpha 0.05.

Frequently get upset about little things. Obtaining a significant difference without multiple test correction were these additional items: [Not] Happy most of the time, Feel life is empty, Often get bored, Hard to start new projects, Trouble concentrating, Feel pretty worthless, and [Do not] Enjoy getting up in the morning. Of the 13 items with between-group differences, six were from the Dysphoria subscale, two from Hopelessness, two from Agitation, and one each from Worry, Cognitive, and WAV. Among the 17 items with similar endorsement by both the nondepressed and subthreshold groups, several were low endorsement items, such as Feel situation is hopeless, Worry about the past and Feel restless and fidgety. In contrast, highly endorsed by both the nondepressed group and the subthreshold group were the cognitive item, Mind [not] as clear as it used to be, and five of the six-WAV items: [Do not] Feel full of energy, [Do not] Find life very exciting, Dropped activities and interests, Prefer to stay at home, and Avoid social gatherings. These items were endorsed by 27–51% of the nondepressed respondents and comparable proportions of the subthreshold depressed group,

so they did not differentiate the subthreshold from the nondepressed group.

Estimation of a conceptual model for subthreshold depression In the full bivariate logistic regression model we estimated first to classify subthreshold depressed versus nondepressed elders, a number of the variables were not associated with subthreshold depression, including age, gender, self-rated health, and IADL functioning and emotional loneliness. A second, more parsimonious equation retained the following variables: marital status, education, race, pain rating, TICS-M cognitive functioning score, grieving, income inadequacy, and social loneliness (Table 4). This model was significant (Model Chi-square ¼ 32.455, p 5 0.001), adequately fit the data according to the Hosmer–Lemshow goodness-of-fit test ( p ¼ 0.484), and predicted group membership with 79.2% accuracy. The model predicted those without depression more accurately than the subthreshold depressed individuals.

689

Aging & Mental Health Table 4. Logistic regression equation for subthreshold depressed vs. nondepressed.1

Marital status Education Race Pain rating TICS-M score Grieving Income adequacy Social loneliness Constant

B

SE

Wald

df

Sig.

Exp(B)

Lower 95% C.I.

Upper 95% C.I.

1.128 1.408 1.535 0.204 0.074 0.897 1.060 0.235 1.557

0.718 0.671 0.856 0.191 0.041 0.493 0.593 0.119 1.612

2.472 4.401 3.216 1.147 3.231 3.311 3.201 3.898 0.932

1 1 1 1 1 1 1 1 1

0.116 0.036 0.073 0.284 0.072 0.069 0.074 0.048 0.334

3.091 4.086 4.643 1.227 0.929 2.452 2.887 1.265 0.211

0.757 1.097 0.867 0.844 0.857 0.933 0.904 1.002

12.613 15.219 24.860 1.783 1.007 6.441 9.221 1.597


Notes: 1Model Chi-Square ¼ 32.455, p 5 0.001. Hosmer and Lemeshow test Chi-Square ¼ 7.494, p ¼ 0.484; Nagelkerke R-square ¼ 0.289. Marital status: 1 ¼ Unmarried, 0 ¼ Married; Education: 1 ¼ High school or lower; Race: 1 ¼ African-American, 0 ¼ White; Pain rating ¼ SF12 Pain question; TICS-M score ¼ Modified telephone interview for cognitive screening score; Grieving: 1 ¼ Yes, 0 ¼ No; Income: 1 ¼ Inadequate, 0 ¼ Adequate; Social loneliness: subscale score from DeJong-giervald loneliness scale.

Two individual variables were significantly associated with membership in the subthreshold depression category: high school education or less (OR ¼ 4.086, p ¼ 0.036) and social loneliness (OR ¼ 1.265, p ¼ 0.048). Those in the high school or less category were approximately four times as likely to be in the subthreshold depression group, and each one point increase on the social loneliness scale equates with a 26% increase in being in the subthreshold depression group. Race, income, and grieving were marginally significant in this equation, with odds ratios of belonging in the subthreshold group of 4.643 for African-American race, 2.887 for inadequate income, and 2.452 for grieving a recent loss.

Discussion Although similar in age and gender distribution, older residents in congregate housing with subthreshold depression were less well educated and were more likely to be unmarried, and to have inadequate income, than those without depression, in uncontrolled differences. Further, in bivariate comparisons the subthreshold depressed group had lower self-rated health, more cognitive impairment, more reported loneliness, and were more likely to report grieving a recent loss. When controlling for the set of variables in a bivariate logistic regression equation, many of these differences remain and some new differences come to light, adding to accumulating evidence that mild depression may be influenced by situational factors such as low income and loneliness (Barg et al., 2006). In the controlled equation, African-American race, lower education and income inadequacy, three related demographic variables, each predicted subthreshold depressed status at p 5 0.10 or 0.05 and with meaningful odds ratios. Of psychosocial variables, only grieving and social loneliness were significant or marginal predictors. Age, gender, self-rated health, and impairment in IADL’s were not associated with subthreshold depression in this sample of old–old, vulnerable elders.

Prior literature examining the phenomenology of subthreshold depression in later life has noted a preponderance of somatic, cognitive, and functional symptoms (Woehr & Goldstein, 2003). In the current study, the subthreshold group’s symptom profile, if taken apart from the comparison group, suggests that low energy, lack of mental clarity, and other WAV issues form a core symptom cluster for this level of depression in older adults. However, when contrasted with the nondepressed comparison group, these results must be seen somewhat differently. Among elders in congregate housing, a majority of them over age 80, many who are frail, functionally impaired, or mildly cognitively impaired, concerns of low energy and cognitive changes were quite common, perhaps forming a core of age-related ‘depletion’ symptoms. Symptoms that differentiated the subthreshold and nondepressed groups were not these depletion symptoms, but were instead negative affect symptoms, lack of positive affect, and lower satisfaction with life. These latter symptoms are far less likely to be reported by nondepressed elders, and may be more likely shared by those who have criterion depression. According to prior research, older adults with major depression also experience additional dysphoric and vegetative symptoms, such as suicidal ideation, feelings of worthlessness, or hopelessness (Blazer, 2003; Lavretsky & Kumar, 2002). Consistent with these findings, Geiselman and Bauer (2000, p. 36) concluded that ‘subthreshold depressive disorder represents a heterogeneous group of milder forms of depression, at least milder than major depression, with qualitatively distinct symptom patterns’. Evidence of both quantitative and qualitative distinction is emerging for subthreshold depression among older adults. Quantitative difference is seen in subthreshold depressed elders reporting numerically fewer symptoms than those with criterion depression and more than nondepressed older adults, while qualitative difference is seen in reporting more symptoms that are shared by nondepressed elders, which tend to be milder, along with a lower


690


likelihood of reporting the most severe symptoms of depression. The GDS items determined the range and the wording of symptoms examined in this study. For instance, unlike the MINI or official diagnostic criteria, the GDS does not include items about sleep or appetite disturbance. In addition, the exact wording of some of the GDS items may have allowed participants to endorse items they might not have if the items were stated in a different form. For example, it may be easier to say you are ‘downhearted and blue’, which 37% of the subthreshold depressed group endorsed on the GDS, than to say you are ‘depressed most of the time’, which only 15.2% of the subthreshold group endorsed as part of the MINI. Chodosh and colleagues (Chodosh, Buckwalter, Blazer, & Seeman, 2004) explored this question in comparing the CES-D and the Hopkins Symptom Checklist, and found systematic differences attributable to the emphasis on frequency in one measure versus the emphasis on level of concern or bother in the other. While the greater range of possible symptoms in the GDS, vis-a`-vis a diagnostic screen such as the MINI, seems to point to a greater potential for identifying concerns of older adults, there may be a potential confound with the GDS due to the way both frequency and bother are addressed informally and inconsistently throughout the questions. Sampling design was a limitation in the current study. The sample was gathered from six different facilities, a fairly heterogeneous group of older residents of congregate housing. Furthermore, due to restrictions on recruiting at some of the facilities, those who completed the self-administered surveys were selfselected. Although we estimate the response rate to be about 10% of the total population of residents in the facilities, it is impossible to know how many residents were actually exposed to information about the study, either from reading an informational flyer or hearing a brief announcement. A sizable number of residents were unlikely to be able to complete the surveys independently due to physical and cognitive disability (Horowitz, 2006). Research in residential settings with older adults is also typically subject to concerns about privacy and lack of perceived benefits (CohenMansfield, 2003; Horowitz, 2006.) On the other hand, of those who completed surveys, most agreed to be phoned for the follow-up interview. Benchmarking our rates of depression with the literature on geriatric depression finds our sample to be within the range of estimates of the prevalence of depressive conditions in residential settings. This suggests that self-selection did not skew the sample in favor of more depressed or less depressed respondents. Other minor limitations to the study should be noted. In comparing responses on the MINI to those on the GDS, there may have been effects of the inevitable delay of 3–10 days between completing the GDS in survey form and responding by phone to the MINI questions, as well as potential effects from

the difference in these two modes of administration. Because only seven participants scored in the range of criterion depression, this group could not be included in statistically meaningful comparisons. Further, cross-sectional data captures symptom endorsement by those with subthreshold depression at only one point in time. Findings here add to growing evidence that subthreshold depression in late life is a form of mild depression, falling somewhere between the severity of Major Depressive Disorder and normal responses to the vicissitudes of aging, with differences in severity as well as in number of symptoms. Although somatic symptoms may be disproportionately represented in subthreshold depression, ‘depression without sadness’ would not be an adequate descriptor for the condition as identified here, where negative affect and negative thoughts played a role. Further, the subthreshold and nondepressed elders did not differ in terms of the health, functioning, and pain related variables in our controlled equation. Essentially, many of these older adults have some health concerns and impairments, just as they endorsed some of the WAV items on the GDS. Therefore, the discriminating issues for subthreshold depression in this sample were related to lower socio-economic status, social losses, and loneliness which appear to bestow added vulnerability to these symptoms. Clinician researchers have maintained that depression among older adults is multiply-determined and presents in several guises. Issues of early onset or late onset, medical co-morbidities, stressful life events such as caregiving or bereavement, and a history of early traumatic losses or troubled relationships each may influence depression’s specific symptoms, severity and prognosis (Blazer, 2003; Garner, 2002; Knight, 2004). Several authors on the topic of nonmajor depression have noted the limitations to strictly bounded diagnostic methods in the assessment of depression among older adults in light of the fluidity of symptoms over time and between categories (Flint, 2002; Judd & Akiskal, 2002; Lavretsky & Kumar, 2002). A spectrum or dimensional approach to depression in late life with focused attention on type and severity of symptoms may be preferable to a categorical diagnostic approach for both clinical practice and research.

Acknowledgement This study was supported by a grant from the John A. Hartford Geriatric Social Work Faculty Scholars Program.

References Adams, K.B. (2001). Depressive symptoms, depletion, or developmental change? Withdrawal, apathy, and lack of vigor in the geriatric depression scale. Gerontologist, 41(6), 768–777.


Aging & Mental Health Adams, K.B., Matto, H.C., & Sanders, S. (2004). Confirmatory factor analysis of the geriatric depression scale. Gerontologist, 44(6), 818–826. Adams, K.B., Sanders, S., & Auth, E. (2004). Loneliness and depression in independent living retirement communities: Risk and resilience factors. Aging and Mental Health, 8(6), 475–485. Akiskal, H.S., Judd, L.L., Gillin, J.C., & Lemmi, H. (1997). Subthreshold depressions: Clinical and polysomnographic validation of dysthymic, residual and masked forms. Journal of Affective Disorders, 45(1–2), 53–63. American Psychiatric Association (2000). Diagnostic and statistical manual of mental disorders DSM-IV-TR (4th ed.). Washington, DC: Author. Barg, F.K., Huss-Ashmore, R., Wittink, M.N., Murray, G.F., Bogner, H.R., & Gallo, J.J. (2006). A mixedmethods approach to understanding loneliness and depression in older adults. The Journals of Gerontology: Series B Psychological sciences and social sciences, 61B(6), S329–S339. Beekman, A.T.F., Penninx, B.W.J.H., Deeg, D.J.H., Ormel, J., Braam, A.W., & van Tilburg, W. (1997). Depression and physical health in later life: Results from the Longitudinal Aging Study Amsterdam (LASA). Journal of Affective Disorders, 46, 219–231. Blazer, D.G. (2002). Self-efficacy and depression in late life: A primary prevention proposal. Aging and Mental Health, 6(4), 315–324. Blazer, D.G. (2003). Depression in late life: Review and commentary. Journals of Gerontology Series A-Biological Sciences and Medical Sciences, 58(3), 249–265. Brink, T.L., Yesavage, J.A., Lum, O., Heersema, P.H., Adey, M., & Rose, T.L. (1982). Screening tests for geriatric depression. Clinical Gerontologist, 1(1), 37–43. Chan, D., Kasper, J.D., Black, B.S., & Rabins, P.V. (2003). Prevalence and correlates of behavioral and psychiatric symptoms in community-dwelling elders with dementia or mild cognitive impairment: The memory and medical care study. International Journal of Geriatric Psychiatry, 18, 174–192. Cheng, S.T., & Chan, A.C.M. (2007). Withdrawal, apathy and lack of vigor in late life depression: Factorial validity and relationship to diagnosis. Aging & Mental Health, 11(5), 532–537. Chodosh, J., Buckwalter, J.G., Blazer, D.G., & Seeman, T.E. (2004). How the question is asked makes a difference in the assessment of depressive symptoms in older persons. American Journal of Geriatric Psychiatry, 12(1), 75–83. Chopra, M.P., Zubritsky, C., Knott, K., Ten Have, T., Hadley, T., Coyne, J.C., et al. (2005). Importance of subsyndromal symptoms of depression in elderly patients. American Journal of Geriatric Psychiatry, 13(7), 597–606. Clare, L. (2003). Managing threats to self: Awareness in early stage Alzheimer’s disease. Social Science and Medicine, 57, 1017–1029. Cohen-Mansfield, J. (2003). Consent and refusal in dementia research: Conceptual and practical considerations. Alzheimer Disease and Associated Disorders, 17(Suppl. 1), S17–S25. Cole, M.G., & Dendukuri, N. (2003). Risk factors for depression among elderly community subjects: A systematic review and meta-analysis. American Journal of Geriatric Psychiatry, 160, 1147–1156.

691

De Jong-Gierveld, J., & Van Tilberg, T. (1999). Manual of the loneliness scale. Amsterdam, Netherlands: Vrige Universitait. Duke University Center for the Study of Aging & Human Development (1978). Multidimensional functional assessment: The OARS methodology. Durham, NC: Author. Fiske, A., Gatz, M., & Pedersen, N.L. (2003). Depressive symptoms and aging: The effects of illness and non-health related events. Journal of Gerontology: Psychological Sciences, 58B, P320–P328. Flint, A.J. (2002). The complexity and challenge of nonmajor depression in late life. American Journal of Geriatric Psychiatry, 10(3), 229–232. Folstein, M.F., Folstein, S.E., & McHugh, P.R. (1975). ‘Mini-Mental State’: A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12, 189–198. Forsell, Y., Palmer, K., & Fratiglioni, L. (2003). Psychiatric symptoms/syndromes in elderly persons with mild cognitive impairment. Data from a cross-sectional study. Acta Neurologica Scandinavica, 107(Supp. 179), 25–28. Gallo, J.J. (2004). Spectrum of depression in late life – Primary study (Abstract); Grant number 5R01MH06221004. Retrieved September 6, 2004, from http.//Crisp. cit.nih.gov/crisp/ Gallo, J.J., Anthony, J.D., & Muthen, B.O. (1994). Age differences in the symptoms of depression: A latent trait analysis. Journals of Gerontology: Psychological Sciences, 49, P251–P264. Gallo, J.J., & Leibowitz, B.D. (1999). The epidemiology of common late-life mental disorders in the community: Themes for a new century. Psychiatric Services, 50, 1158–1168. Gallo, J.J., & Rabins, P.V. (1999). Depression without sadness: Alternative presentations of depression in late life. American Family Physician, 60(3), 820–826. Gallo, J.J., Rabins, P.V., Lyketsos, C.G., Tien, A.Y., & Anthony, J.C. (1997). Depression without sadness: Functional outcomes of nondysphoric depression in later life. Journal of the American Geriatric Society, 45, 570–578. Gallo, J.J., Rebok, G.W., Tennstedt, S., Wadley, V.G., & Horgas, A. (2003). Linking depressive symptoms and functional disability in late life. Aging and Mental Health, 7, 460–480. Garner, J. (2002). Psychodynamic work and older adults. Advances in Psychiatric Treatment, 8, 128–135. Geiselmann, B., & Bauer, M. (2000). Subthreshold depression in the elderly: Qualitative or quantitative distinction? Comprehensive Psychiatry, 41(2), 32–38. Geiselmann, B., Linden, M., & Helmchen, H. (2001). Psychiatrists’ diagnoses of subthreshold depression in old age: Frequency and correlates. Psychological Medicine, 31(1), 51–63. Haringsma, R., Engels, G.I., Beekman, A.T.F., & Spinhoven, P. (2004). The criterion validity of the Center for Epidemiological Studies Depression Scale (CES-D) in a sample of self-referred elders with depressive symptomatology. International Journal of Geriatric Psychiatry, 19(6), 558–563. Holst, G., & Holberg, I.R. (2003). Exploring the meaning of everyday life, for those suffering from dementia. American Journal of Alzheimer’s Disease and Other Dementias, 18(6), 359–365.


692


Horowitz, A. (2006). Issues in conducting social work research in aging. In B. Berkman (Ed.), Handbook of social work in health and aging (pp. 989–1000). New York: Oxford University Press. Horowitz, A., Reinhardt, J.P., & Kennedy, G.J. (2005). Major and subthreshold depression among older adults seeking vision rehabilitation services. American Journal of Geriatric Psychiatry, 13(3), 180–187. Judd, L.L., & Akiskal, H.S. (2002). The clinical and public health relevance of current research on subthreshold depressive symptoms to elderly patients. American Journal of Geriatric Psychiatry, 10(3), 233–238. Judd, L.L., Akiskal, H.S., & Paulus, M.P. (1997). The role and clinical significance of subsyndromal depressive symptoms (SSD) in unipolar major depressive disorder. Journal of Affective Disorders, 45, 5–18. Kafonek, S., Ettinger, W.H., Roca, R., Kittner, S., Taylor, N., & German, P.S. (1989). Instruments for screening for depression and Dementia in a long-term care facility. Journal of the American Geriatrics Society, 37(1), 29–34. Knight, B.G. (2004). Psychotherapy with older adults (3rd ed.). Thousand Oaks, CA: Sage. Kumar, A., Lavretsky, H., & Elderkin-Thompson, V. (2004). Nonmajor clinically significant depression in the elderly. In S.P. Roose, & H.A. Sackeim (Eds.), Late-life depression (p. 64). New York: Oxford University Press. Lavretsky, H., & Kumar, A. (2002). Clinically significant non-major depression – Old concepts, new insights. American Journal of Geriatric Psychiatry, 10(3), 239–255. Lewinsohn, P.M., Solomon, A., Seeley, J.R., & Zeiss, A. (2000). Clinical implications of ‘subthreshold’ depressive symptoms. Journal of Abnormal Psychology, 109(2), 345–351. Lyness, J.M., King, D.A., Cox, C., Yoediono, Z., & Caine, E.D. (1999). The importance of subsyndromal depression in older primary care patients: Prevalence and associated functional disability. Journal of the American Geriatrics Society, 47(6), 647–652. Lyons, J.S., Strain, J.J., Hammer, J.S., Ackerman, A.D., & Fulop, G. (1989). Reliability, validity, and temporal stability of the geriatric depression scale in hospitalized elderly. International Journal of Psychiatry in Medicine, 19(2), 203–209. National Institute of Mental Health (NIMH) (2007). Older adults: Depression and suicide facts. Retrieved November 13, 2008, from http://www.nimh.nih.gov/ health/publications/older-adults-depression-and-suicidefacts.shtml Newman, J.P., Klein, M.H., Jensen, J.E., & Essex, M.J. (1996). Depressive symptom experience among older women: A comparison of alternative measurement approaches. Psychology and Aging, 11, 112–126. Olfson, M., Broadhead, W.E., Weissman, M.M., Leon, A.C., Farber, L., Hoven, C., et al. (1996). Subthreshold psychiatric symptoms in a primary care group practice. Archives of General Psychiatry, 53, 880–886. Parmelee, P.A., Katz, I., & Lawton, M.P. (1991). The relationship of pain to depression among institutionalized aged. Journal of Gerontology: Psychological Sciences, 46, 15–21. Parmelee, P.A., Harralson, T.L., Smith, L.A., & Schumacher, H.R. (2007). Necessary and discretionary

activities in knee osteoarthritis: Do they mediate the paindepression relationship?. Pain Medicine, 8, 449–461. Pett, M.A., Lackey, N.R., & Sullivan, J.J. (2003). Making sense of factor analysis. Thousand Oaks: Sage. Pinquart, M., & Sorensen, S. (2001). Influences on loneliness in older adults: A meta-analysis. Basic and Applied Psychology, 23(4), 245–268. Rabheru, K. (2004). Special issues in the management of depression in older patients. The Canadian Journal of Psychiatry, 49(Suppl. 1), 41S–50S. Rapaport, M.H., Judd, L.L., Schettler, P.J., Yonkers, K.A., Thase, M.E., Kupfer, D.J., et al. (2002). A descriptive analysis of minor depression. American Journal of Psychiatry, 159(4), 637–643. Royall, D.R. (2004). The ‘Subsyndromal’ syndromes of aging. Journal of the American Geriatrics Society, 52(3), 463–465. Schoevers, R.A., Beekman, A.T.F., Deeg, D.J.H., Geerlings, M.I., Jonker, C., & van Tilburg, W. (2000). Risk factors for depression in later life; results of a prospective community based study (AMSTEL). Journal of Affective Disorders, 59, 127–137. Seidlitz, L., Lyness, J.M., Conwell, Y., Duberstein, P.R., & Cox, C. (2001). Profile of discrete emotions in affective disorders in older primary care patients. Gerontologist, 41(5), 643–651. Sheehan, D.V., Lecrubier, Y., Sheehan, K.H., Amorim, P., Janavs, J., Weiller, E., et al. (1998). The Mini-International Neuropsychiatric Interview (MINI): The development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. Journal of Clinical Psychiatry, 59, 22–33. Shvartzman, P., Weiner, Z., Vardy, D., Friger, M., Sherf, M., & Biderman, A. (2005). Health services utilization by depressive patients identified by the MINI questionnaire in a primary care setting. Scandinavian Journal of Primary Health Care, 23(1), 18–25. Sokal, R.R., & Rohlf, F.J. (1995). Biometry: The principles and practice of statistics in biological research (3rd ed.). New York: W.H. Freeman and Co. Turvey, C.L., Carney, C., Arndt, S., Wallace, R.B., & Herzog, R. (1999). Conjugal loss and syndromal depression in a sample of elders aged 70 years or older. American Journal of Geriatric Psychiatry, 156, 1596–1601. Watson, L.C., Lewis, C.L., Kistler, C.E., Amick, H.R., & Boustani, M. (2004). Can we trust depression screening instruments in healthy ‘old–old’ adults? International Journal of Geriatric Psychiatry, 19(3), 278–285. Welsh, K.A., Breitner, J.C.S., & Magruderhabib, K.M. (1993). Detection of dementia in the elderly using telephone screening of cognitive status. Neuropsychiatry Neuropsychology and Behavioral Neurology, 6(2), 103–110. Woehr, J.L., & Goldstein, M. (2003). Geriatric nonmajor depression symptoms: Dysthymia, subsyndromal depression, and other nonmajor depressive disorders in the elderly. In J.M. Ellison, & S. Verma (Eds.), Depression in later life: A multi-disciplinary psychiatric approach (pp. 79–107). New York: Marcel Dekker. Yesavage, J.A., Brink, T.L., Rose, T.L., Lum, O., Huang, V., Adey, M., et al. (1983). Development and validation of a geriatric depression screening scale – A preliminaryreport. Journal of Psychiatric Research, 17(1), 37–49.