Psychological Medicine (2011), 41, 2535–2546. f Cambridge University Press 2011 doi:10.1017/S0033291711000560
O R I G I N A L AR T I C LE
The relationship between coping and subclinical psychotic experiences in adolescents from the general population – a longitudinal study A. Lin1,2*#, J. T. W. Wigman3#, B. Nelson1, W. A. M. Vollebergh3, J. van Os4,5, G. Baksheev1, J. Ryan1, Q. A. W. Raaijmakers6, A. Thompson1 and A. R. Yung1 1
Orygen Youth Health Research Centre and Centre for Youth Mental Health, University of Melbourne, Victoria, Australia School of Psychology, University of Birmingham, Edgbaston, Birmingham, UK 3 Department of Interdisciplinary Social Science, University of Utrecht, Utrecht, The Netherlands 4 Department of Psychiatry and Psychology, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands 5 King’s College London, King’s Health Partners, Department of Psychosis Studies, Institute of Psychiatry, London, UK 6 Research Center Adolescent Development, University of Utrecht, Utrecht, The Netherlands 2
Background. Subclinical psychotic experiences during adolescence may represent liability for developing psychotic disorder. Both coping style and the degree of persistence of psychotic experiences may play a role in the progression to clinical psychotic disorder, but little is known about the causal relationship between the two. Method. Path modelling was used to examine longitudinal relationships between subclinical positive psychotic experiences and three styles of coping (task-, emotion- and avoidance-oriented) in an adolescent general population sample (n=813) assessed three times in 3 years. Distinct developmental trajectories of psychotic experiences, identified with growth mixture modelling, were compared on the use of these coping styles. Results. Over time, emotion-oriented coping in general was bi-directionally related to psychotic experiences. No meaningful results were found for task- or avoidance-oriented coping. Females reported using a wider range of coping styles than males, but the paths between coping and psychotic experiences did not differ by gender. Persistence of psychotic experiences was associated with a greater use of emotion-oriented coping, whereas a decrease in experiences over time was associated with an increased use of task-orientated coping. Conclusions. Emotion-oriented coping is the most important coping style in relation to psychotic experiences, as it may contribute to a ‘ vicious cycle ’ and is associated with persistence of experiences. In addition, more task-oriented coping may result in a decrease in psychotic experiences. Results suggest that opportunities for intervention may already be present at the level of subclinical psychosis. Received 12 October 2010 ; Revised 14 March 2011 ; Accepted 17 March 2011 ; First published online 28 April 2011 Key words : Coping, development, general population, subclinical psychotic experiences.
Introduction Subclinical psychotic experiences are common in the general population, implying a continuum of the psychosis phenotype (Johns & van Os, 2001 ; Scott et al. 2006 ; van Os et al. 2009, Yung et al. 2009 ; Nuevo et al. 2010). While most experiences are transient and resolve spontaneously (Dhossche et al. 2002 ; Hanssen et al. 2005 ; Wiles et al. 2006 ; Dominguez et al. 2011), a small proportion of individuals with mild psychotic * Address for correspondence : Ms. A. Lin, Orygen Youth Health Research Centre and Centre for Youth Mental Health, University of Melbourne, 35 Poplar Road, Melbourne 3052, Australia. (Email :
[email protected]) # These authors contributed equally as joint first authors.
experiences will progress to psychotic disorder (Poulton et al. 2000). Low-level delusional thinking and mild hallucinations often precede clinical disorder (e.g. Yung & McGorry, 1996 ; Poulton et al. 2000 ; Welham et al. 2009), particularly when persistent (Dominguez et al. 2011). During adolescence, when psychosis proneness is at its peak (Verdoux et al. 1998), subtle psychotic experiences are frequently reported (Wigman et al. 2009 ; Yung et al. 2009). A suggested paradigm for understanding the development of psychosis is the proneness–persistence– impairment model. This model proposes that transition from subclinical psychosis to clinical disorder is preceded by the persistence of these subtle psychotic experiences and accompanied by
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progressive impairment, depending on additional psychopathological, developmental and psychological factors which lead to (i) persistence of these experiences and (ii) need for care (Cougnard et al. 2007 ; van Os et al. 2009). Focus on the development of subclinical psychotic symptoms over time, rather than on crosssectional and possibly transient psychotic experiences, may be useful in distinguishing true underlying vulnerability to schizophrenia from incidental, benign experiences or clinical ‘ noise ’ around a non-psychotic disorder (Nelson & Yung, 2009 ; Yung et al. 2009). Previous studies have found that persistence of subclinical psychotic experiences in general population samples is associated with poor outcome, such as diagnosis of psychotic disorder (Dominguez et al. 2011), poor social functioning (Ro¨ssler et al. 2007), high levels of depression (Mackie et al. 2010 ; Wigman et al. 2011) or negative symptoms (Dominguez et al. 2010) and greater use of health care (Wigman et al. 2011). Coping style may play a role in shifts along the extended psychosis continuum, i.e. in persistence and possible development of clinical psychotic disorder (Krabbendam et al. 2005 ; Philips et al. 2009). Coping has been defined in a number of ways, one distinction being between task-oriented coping (e.g. talking to someone, actively looking for a solution), emotion-oriented coping (e.g. worry, selfblame) and avoidance-oriented coping (e.g. distraction, social diversion) styles (Endler & Parker, 1990). In general, task-focused coping is more adaptive in dealing with psychotic symptoms and daily stressors than emotionally driven coping (Phillips et al. 2009). Such adaptive coping is related to feelings of control and higher levels of functioning (Bak et al. 2003 ; Krabbendam et al. 2005). Coping is related to psychotic symptoms at all levels of the extended psychosis continuum : non-adaptive coping is associated with poor outcome in chronic schizophrenia populations (Ritsner et al. 2003), first-episode (Boschi et al. 2000 ; Thompson et al. 2003) and ultra-high risk for psychosis (Ruhrmann et al. 2008) samples, and within the general population (Schuldberg et al. 1996 ; Bak et al. 2003 ; Krabbendam et al. 2005 ; Dangelmaier et al. 2006). Gender differences in coping with psychotic symptoms have been identified, but findings are inconsistent. Some studies show no differences between genders (Boschi et al. 2000 ; Dangelmaier et al. 2006 ; Modestin et al. 2009), whereas others report that females use more adaptive coping strategies than their male counterparts (Thompson et al. 2003). To date, most research on coping and psychosis has been cross-sectional. This is a limitation, as it does not allow causal inferences to be drawn on the relationship between the two. To better identify individuals at highest risk of developing a psychotic disorder,
longitudinal data are necessary to clarify the mechanisms that might be associated with the persistence of subclinical psychotic experiences and possible transition to psychotic disorder. Investigating different coping styles in relation to developmental trajectories of subclinical psychotic experiences may inform possible preventive interventions, since coping with psychotic symptoms has been shown to be modifiable through psychotherapy (Farhall et al. 2007). Given that intervention may be most beneficial when applied before the onset of psychotic disorder (Mrazek & Haggerty, 1994 ; McGorry et al. 2006), the rationale for understanding the relationships between subclinical psychotic experiences and coping is evident. Aims and hypotheses The present study investigated the relationship between subclinical positive psychotic experiences and coping styles (emotion-, task- and avoidance-oriented) over 3 years in a large adolescent general population cohort. First, the associations between subclinical positive psychotic experiences and different coping styles over time were assessed bi-directionally. Second, distinct developmental trajectories of subclinical psychotic experiences were identified and compared on measures of general psychopathology. Third, the mean use of different coping styles was compared across each trajectory. Since higher levels of psychopathological problems are associated with the use of more coping styles in general (Escher et al. 2003), the proportional use of each coping style was also investigated. It was hypothesized that : (i) the increased use of emotion- and avoidance-oriented coping would be longitudinally associated with higher levels of subclinical positive psychotic experiences, (ii) increasing or persistent trajectories of psychotic experiences would be associated with higher levels of psychopathology and lower functioning, and with (iii) more use of emotion- and avoidance-oriented, and less taskoriented coping. Method Participants Participants were recruited through secondary schools in Western Metropolitan Melbourne, Australia ; 60 secondary schools were approached and 34 consented (20 government, five Catholic and nine independent schools). Three data collection waves were completed : T1 (baseline), n=813 ; T2 (12 months after baseline assessment), n=646 (73 % of original cohort) ; and T3 (3 years after baseline assessment), n=514
Coping and subclinical psychotic experiences in adolescents (58 % of original cohort). At baseline, 51 % of the sample was female. Mean age was 15.6 (S.D.=2.6) years. Procedure At T1, students were assessed via questionnaire during one study period. Trained research assistants were present to answer queries. All participants provided written informed consent and assent from their parent/guardian. The second wave of data collection (T2) was conducted 12 months later. This assessment comprised semi-structured interview and questionnaires. Written consent was again obtained from participants and from their parent/guardian if they were still under the age of 18 years. This process was repeated 3 years after baseline (T3). The study was approved by Research and Ethics Committees at the University of Melbourne, Victorian Department of Education and Catholic Education Office. Instruments The Community Assessment of Psychic Experiences (CAPE) positive experiences subscale (20 self-reported items) was used to assess psychotic experiences in all study phases (Stefanis et al. 2002 ; Konings et al. 2006). Each item rates two aspects of psychotic experiences (frequency and associated distress) on a four-point scale of never/not distressed (1) to nearly always/ very distressed (4). The 20 frequency items showed good internal consistency at all time points (Cronbach’s a=0.82 to 0.85). Sum scores were used as continuous indicators of subclinical positive psychotic experiences. Coping styles were assessed using the adolescent version of the Coping Inventory for Stressful Situations (CISS ; Endler & Parker, 1990). Three different coping styles were assessed on a five-point scale of not at all (1) to very much (5). Task-oriented coping refers to purposeful efforts aimed at solving the problem, cognitively or physically. Emotion-oriented coping describes self-oriented emotional reactions, self-preoccupation and fantasizing. Avoidanceoriented coping refers to activities and cognitive changes intended to avoid the situation (Endler & Parker, 1990). Scores for each coping style were calculated as the sum of item scores per style at each time point. The proportional use of each coping style was calculated from the total amount of all coping styles used by the individual at each time point. Internal consistency of the CISS was good at all assessments (Cronbach’s a=0.88 to 0.91). The Centre for Epidemiologic Studies Depression Scale (CES-D) assessed depressive symptomatology over the past week (Radloff, 1977). The CES-D consists of 20 self-report items rating frequency of depressive
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symptoms. General mental health was measured using the General Health Questionnaire-12 (GHQ-12), a 12-item self-report screen for psychological strain in the general population (Goldberg & Williams, 1988). The Revised Multidimensional Assessment of Functioning Scale (RMAFS) is a 23-item self-report questionnaire, designed at Orygen Youth Health, to assess functioning in the domains of family, peer and general daily life. Items are rated from not at all/rarely applicable (0) to (almost) always applicable (5). Higher scores indicate better functioning. Analyses Analyses were conducted with Mplus 5.1 (Muthe´n & Muthe´n, 1998–2007 ; Muthe´n & Muthe´n, USA) and PASW Statistics 18 (SPSS Inc., USA). Full information maximum likelihood (FIML) was used for estimation of missing values and, given that data were nonnormally distributed, robust maximum likelihood was used for model estimation. This method estimates a mean-adjusted x2 robust to non-normality (Brown, 2006). Differences between participants who completed all assessments and those who dropped out at T2 or T3 were analysed using analysis of variance for continuous variables and odds ratios (ORs) for binary variables. Step 1 : path analysis Path analysis was used to investigate the relationships between subclinical positive psychotic experiences and the different coping styles (task-, emotion- and avoidance-oriented) over time, using only observed variables. Paths were drawn to allow psychotic experiences to predict the three different coping styles over time and vice versa. The CAPE score and the three scores on the different coping styles were allowed to correlate at all time points, but the three coping styles were not allowed to predict other coping styles over time because this was not of primary interest. Several fit indices were used for model evaluation (Brown, 2006). For good model fit, the x2 should be low ; the comparative fix index (CFI) should be above 0.90 or 0.95 and the root mean square error of approximation (RMSEA) should be lower than 0.08 or 0.05 for acceptable and good model fit, respectively. Multi-group analysis on gender was conducted to investigate whether regression coefficients differed for gender. To do this, two models were compared : (i) a model with the different paths constrained to be equal for both genders and (ii) a model with the paths freely estimated. If the model with the freely estimated paths does not differ significantly from the constrained
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Fig. 1. Path model of positive subclinical psychotic experiences and different coping styles (task-, emotion- and avoidanceoriented). Only significant paths are shown. The values represent b coefficients. Minor differences in the model when controlled for depression are outlined in the Results section.
model, paths can be considered to be equal for females and males. Models do not significantly differ if nCFI
