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Thought Suppression in Obsessive–Compulsive Disorder Jessica R. Grisham, PhD and Melissa J. Black, BPsych(Hons) University of New South Wales, Australia
Abstract Understanding the effects of thought suppression is critical to our understanding of obsessive–compulsive disorder (OCD); a disorder characterised by persistent intrusive thoughts and efforts to suppress these thoughts. In the current paper, we explain the prominent theoretical model of thought suppression, Wegner's Ironic Process Theory, which posits that attempts to suppress our intrusions are counterproductive at best. We also provide an overview of the empirical findings regarding this theory in nonclinical and clinical OCD samples. We then outline current directions in thought suppression research that extend beyond simply measuring frequency of intrusive thoughts, including consideration of the persistence of intrusions, disengagement from them, and the associated distress. We conclude with a discussion of the implications of thought suppression research with respect to clinical interventions for OCD. This includes consideration of opportunities for future clinical research on OCD and thought suppression, including novel interventions such as cognitive bias modification.
6 A professional woman attends a formal work function and experiences an unexpected intrusive image of tearing off her clothes and jumping in the fountain. She is horrified by this image and fiercely attempts to banish it from her mind. Unfortunately, the harder she tries to block this disturbing thought, the more she catches it popping up during her conversations with colleagues. Similar to this woman, many people find that intentional attempts to control unwanted thoughts, desires, and feelings are unsuccessful and produce a so-called rebound effect, in which they increase rather than decrease in frequency and intensity (Wegner, 2009). However, the nature of intrusive thoughts, and the impact of efforts to control them, has critical relevance to understanding obsessive–compulsive disorder (OCD). In this review, we focus on the notion of the thought suppression as a key maintaining mechanism for OCD. We also discuss clinical implications and strategies for addressing thought suppression in OCD.
OCD is characterised by recurrent and persistent ideas, thoughts, images, or impulses that are intrusive, unwanted, and cause marked anxiety or distress (American Psychiatric Association, 2013). Individuals with OCD often try to suppress distressing intrusive thoughts (Freeston & Ladouceur, 1997). Research has found that intrusive thoughts in the general population are similar in content to obsessions in OCD, which has led to the suggestion of continuity between normal and abnormal obsessions (Clark et al., 2014; Rachman & de Silva, 1978; Salkovskis, 1985). Individuals with OCD, however, experience obsessions as more frequent, more unacceptable, more difficult to dismiss, and more intense (Garcia-Soriano, Belloch, Morillo, & Clark, 2011; Rachman & de Silva, 1978). Cognitive behaviour therapy (CBT) models assert that a normal intrusive thought can escalate into an obsession if it is interpreted as signifying a threat to self or others, which leads to efforts to suppress and neutralise thoughts (i.e., via compulsions). These efforts to control or suppress obsessions are proposed to lead to a
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Corresponding author:
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paradoxical increase in the thoughts and in distress (Tolin, Abramowitz, Przeworski, & Foa, 2002). Thus the process of responding to obsessions by attempting to suppress them has been proposed to be a significant factor in the aetiology and maintenance of OCD (Salkovskis, 1985, 1989). Wegner's Model In the seminal "white bear" study of the paradoxical effect of thought suppression, Wegner, Schneider, Carter, and White (1987) demonstrated that participants instructed not to think about a white bear were unable to suppress intrusions about the white bear while verbalising a stream of consciousness. Perhaps more interestingly, these participants subsequently reported more white bear thoughts than individuals who had not been instructed to suppress. A follow-up experiment showed that participants were more likely to successfully suppress the unwanted thought if they were given a specific thought (a red Volkswagen) to use as a distractor, although this finding was not reliable (Wegner, Schneider, Carter, & White, 1987). To explain this phenomenon, Wegner (1994) proposed the ironic process theory. This theory describes two processes that may occur during attempted mental control, such as when participants suppressed white bear thoughts. The first is an intentional search for a distracter thought, and the second is an automatic search for the unwanted thought (Wegner, 1994). The automatic monitoring paradoxically increases the target thought's accessibility to consciousness by continually searching for the target (Wegner, Erber, & Zanakos, 1993). Many studies have attempted to replicate the white bear effect, usually with nonclinical undergraduate samples. In these studies, researchers compare individuals instructed to suppress a target thought and those simply asked to monitor their thoughts with respect to the frequency of thoughts during the experimental period and during a subsequent "rebound" period. Abramowitz, Tolin, and Street (2001) conducted a quantitative meta-analysis of controlled
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! studies examining thought suppression. Although the literature findings were inconsistent, many studies found support or partial support for a post-suppression rebound effect. Their analysis found that participants were often able to suppress unwanted thoughts over a short period of time, but that with longer suppression periods and difficulty sustaining efforts, thought suppression became more difficult.
control are also associated with greater suppression effort and poorer mood state (Belloch, Morillo, & Gimenez, 2004; Corcoran & Woody, 2008; Grisham & Williams, 2009; Najmi et al., 2009; Purdon, 2001; Purdon et al., 2005). Indeed, a recent meta-analysis found that people with OCD displayed a reduced initial enhancement effect of thought suppression, associated with increased motivation and effort to suppress unwanted thoughts (Magee, Harden, & Teachman, 2012).
Thought Suppression among Individuals with OCD
Purdon (2004) suggested examining the impact of thought suppression on thought persistence rather than thought frequency. Similarly, Lambert, Hu, Magee, Beadel, and Teachman (2014) suggested that thought return duration is equally important to thought frequency as it may reflect the ease with which participants can disengage from unwanted thoughts. Amongst clinical populations, persistence and/or disengagement may represent a key target for a clinical intervention for unwanted thoughts; that is, being able to experience an unwanted thought and reducing the distress associated with it by reappraising the thought or dismissing it through distraction or substitution.
Chronic thought suppression has been shown to be associated with OCD. Wegner and Zakanos (1994) found that a measure of thought suppression (the White Bear Suppression Inventory) correlated with a measure of OCD, and also predicted clinical obsessions among individuals prone to OCD. Other studies have documented the common use of thought suppression in OCD samples. Freeston and Ladouceur (1997) found that 76% of their sample used thought suppression to manage their obsessions. Similarly, Purdon, Rowa, and Antony (2007) found that OCD patients were spending more than 3.5 hours per day trying to suppress unwanted intrusive thoughts. In addition to naturalistic studies, researchers have conducted experimental studies in which they compare the effects of thought suppression with a control condition among individuals diagnosed with OCD. Contrary to the predictions of the model, however, several studies in clinical OCD samples have failed to demonstrate that suppression leads to an increase in thought frequency (Janeck & Calamari, 1999; Najmi, Riemann, & Wegner, 2009; Purdon, Rowa, & Antony, 2005). One possible explanation for this finding is that individuals with OCD have a great deal of practice as they are constantly suppressing and resisting their obsessions. Abramowitz and colleagues (2001) noted that an instruction to suppress an unwanted thought is the equivalent of asking OCD participants to maintain their natural tendency to resist these thoughts. Indeed, Purdon (2001) found that asking OCD participants to not suppress their thoughts was more aversive than a suppression induction, given the short-term relief that neutralisation strategies induce. Other studies, however, have demonstrated a paradoxical thought suppression effect in OCD samples (McLaren & Crowe, 2003; Rassin & Diepstraten, 2003; Tolin et al., 2002). Tolin and colleagues (2002) found that OCD participants showed a paradoxical increase in unwanted thoughts when asked to not think of a white bear, whilst anxious and non-anxious control participants did not. To address the limitations associated with self-report data for thought suppression, Tolin et al. (2002) conducted a second study in which they used a lexical decision task to test decision times for suppressed words compared to nonsuppressed words. The results of this study replicated those of the previous study, showing an increase in white bear thoughts for OCD participants, but not for anxious or nonanxious controls (Tolin et al., 2002). Many studies with clinical OCD samples have shown that, even if there is no increase in frequency associated with suppression, appraisals of failures of thought
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A limited number of studies have examined whether individuals with OCD may experience more thought suppression failures due to neuropsychological characteristics (e.g., Demeter, Keresztes, Harsanyi, Csigo, & Racsmany, 2014; Grisham & Williams, 2013; Harsanyi et al., 2014). Brewin and Smart (2005) found some evidence that individual differences in cognitive abilities affect the ability to suppress thoughts in a nonclinical sample. Better working memory was related to fewer intrusions in a suppression condition, suggesting a specific association with attempts to inhibit unwanted thoughts. A study conducted in our laboratory compared responses to an experimentally induced intrusive thought in a group of participants diagnosed with OCD, an anxious comparison group, and a nonclinical control group (Grisham & Williams, 2013). Although the OCD group demonstrated significantly worse performance on several neuropsychological tasks, their performance did not predict their response to a novel intrusive thought. The critical factor in determining their cognitive and emotional response was their beliefs about the importance of controlling one's thoughts, in other words, their interpretative bias. Another recent study with a clinical OCD sample also found that self-reported obsessions were not associated with impaired executive functions on a cognitive test battery (Harsanyi et al., 2014). Implications for Intervention Wegner (1989) suggested that the lesson from thought suppression studies is: "in many cases of unwanted thought, it may be best to stop suppressing" (p. 174). The question of how we should stop suppressing, however, has yet to be sufficiently addressed. However, it is possible that asking what is the best response is the wrong question with respect to obsessions. Rather than focussing on response to an intrusive thought, evidence of the importance of interpretation suggests that cognitive restructuring and reappraisal of the intrusion is still the best strategy. Cognitive behavioural therapy for OCD focuses on challenging distorted beliefs about thoughts: inflated responsibility, need to control thoughts, overestimation of threat, intolerance of
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! uncertainty, and perfectionism (Obsessive Compulsive Cognitions Working Group, 1997). A recent meta-analysis of 16 randomised controlled trials supports the efficacy of cognitive and behavioural approaches for OCD (Olatunji, Davis, Powers, & Smits, 2013).
behavioural approaches. More specifically, CBM could be administered prior to exposure-based treatment or as homework throughout therapy. CBM may also be delivered remotely at a low cost as part of internet-delivered CBT (Williams & Grisham, 2013).
In cognitive approaches to OCD, several techniques help patients challenge and modify these dysfunctional beliefs and reduce their need to control thoughts (Wilhelm & Steketee, 2006). For example, a therapist may begin with normalising intrusions by showing clients a list of intrusive thoughts reported by individuals without OCD. Therapists may also conduct behavioural experiments to test maladaptive predictions. For example, a client may deliberately think about a negative outcome (e.g., breaking a leg) to happen to the therapist, make predictions, and assess the outcome. Similarly, a therapist may ask her client to record the frequency of intrusions when suppressing versus not suppressing a target thought.
Other possible approaches promote alternative strategies for the management of unwanted thoughts. Acceptance and commitment therapy (ACT; Hayes, Strosahl, & Wilson, 1999) focuses on encouraging patients to experience uncomfortable thoughts and feelings without avoiding, struggling with, or viewing them as being true. Hayes and colleagues suggested that acceptance is achieved through the absence of control attempts. Marcks and Woods (2005) found that nonclinical participants who used an acceptance-based strategy experienced a decrease in discomfort level associated with intrusive thoughts (although not thought frequency) compared to suppression. Also, using an undergraduate sample, Fabricant, Abramowitz, Dehlin, and Twohig (2013) extended this work by comparing ACT with a well-established treatment, imaginal exposure (IE), and an expressive writing control condition for obsessional thoughts. The authors reported significant reductions on several outcome measures, including obsessional severity, distress and willingness to experience intrusive thoughts, and negative appraisals of intrusive thoughts. Counter to predictions, however, there were no differences between ACT and IE with respect to either efficacy or change processes (Fabricant et al., 2013).
Although CBT has the strongest evidence, other adjunctive and complementary approaches for altering interpretations may ultimately prove useful in treating OCD. For example, researchers have been developing cognitive bias modification for interpretation (CBM-I) specifically for modifying maladaptive beliefs in OCD. CBM-I protocols for OCD are derived from existing methodologies that have demonstrated efficacy in inducing interpretation biases by resolving the ambiguity of threat information in a positive or negative manner (Mathews & Mackintosh, 2000). In CBM-I, participants are typically presented with relevant scenarios that are emotionally ambiguous up to a final missing word. For example, "You and a friend are having a personal discussion. You tell her that you occasionally have bizarre unpleasant thoughts about hurting people you care about. Your friend tells you this is really ___". For a positive training item, the final word resolves the ambiguity in a benign way (e.g., "normal"). For a negative training item, the word "weird" would be used to resolve the scenario. Participants are typically randomised to either a positive cognitive bias modification (CBM) condition or a neutral condition containing half positive and half negative CBM items. Outcomes are assessed on self-report symptom measures, interpretations of novel ambiguous scenarios, behavioural tasks, and physiological measures. Preliminary work from our laboratory and others suggests that CBM may be useful in reducing OCD-relevant biases such as importance of thoughts, control of thoughts, perfectionism, intolerance of uncertainty, responsibility, contamination, and estimation of threat (Obsessive Compulsive Cognitions Working Group, 1997). However, findings are still mixed (Clerkin & Teachman, 2011; Grisham, Becker, Williams, Whitton, & Makkar, 2014; Williams & Grisham, 2013). Our ongoing research examines whether using CBM to modify biases regarding the importance of thoughts could result in decreased use of thought suppression. Future research should also examine the clinical utility of CBM for OCD with treatment-seeking individuals. CBM may ultimately be used as an adjunct that could improve clinical outcomes and/or reduce relapse rates for OCD when combined with traditional cognitive and
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Examining research on acceptance with clinical OCD samples, Najmi et al. (2009) compared suppression, focused distraction, and acceptance for individuals diagnosed with OCD and healthy control participants. They found that for the OCD group, suppression was not associated with more frequent intrusions, but it was associated with a rebound of distress once suppression was abandoned, whereas acceptance led to a reduction in distress. OCD participants who used focused distraction experienced low distress both during and after the task. However, the authors acknowledged that although distraction may be effective in the short term, there is some evidence that distraction may not be the most effective strategy (Wahl, Huelle, Zurowski, & Kordon, 2013; Wegner, 2011). A related study compared the effectiveness of mindfulness-based strategy versus a focussed distraction strategy on responses to obsessive thoughts in OCD participants. Those who engaged in mindfulness of obsessive thoughts reported lower anxiety and fewer urges to neutralise or suppress than the distraction condition (Wahl et al., 2013). Despite a smaller research base, a recent metaanalysis found that ACT is equally effective as CBT in the treatment of anxiety and OCD spectrum disorders (Bluett, Homan, Morrison, Levin, & Twohig, 2014). Wegner (2011) noted that while some of these strategies for managing thought suppression are helpful, many are experimental and thus future research is needed to determine their effectiveness and the mechanisms through which they work. Future research may also examine how cognitive appraisal of intrusive thoughts interacts with various suppression strategies to determine how best to reduce the distress associated with experiencing unwanted thoughts in OCD (Wegner, 2011).
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! Conclusion Wegner's ironic process theory proposes that the suppression of intrusive thoughts is a counterproductive strategy that leads to rebound of thoughts. Experimental work in undergraduate and clinical OCD samples has provided mixed evidence regarding whether suppression of intrusive thoughts leads to an increase in intrusions, with more consistent evidence that suppression leads to increased distress, especially for those with OCD. From a clinical perspective, the best supported therapeutic approach to thought suppression in OCD is to alter the client's interpretations of their intrusive thought so they do not feel that they need to suppress in the first place. Accordingly, several cognitive behavioural techniques may be used to challenge client's maladaptive beliefs about the meaning and importance of intrusive thoughts and reduce suppression efforts. Other emerging treatment strategies, such as CBM-I and acceptance-based approaches, may also prove useful in promoting more adaptive responses to obsessional thoughts. Future research should continue investigating the mechanisms by which suppressing thoughts maintains OCD. References Abramowitz, J. S., Tolin, D. F., & Street, G. P. (2001). Paradoxical effects of thought suppression: A metaanalysis of controlled studies. Clinical Psychology Review, 21(5), 683–703. American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA: Author. Belloch, A., Morillo, C., & Gimenez, A. (2004). Effects of suppressing neutral and obsession-like thoughts in normal subjects: Beyond frequency. Behaviour Research and Therapy, 42(7), 841–857. doi: 10.1016/j.brat.2003.07.007 Bluett, E. J., Homan, K. J., Morrison, K. L., Levin, M. E., & Twohig, M. P. (2014). Acceptance and commitment therapy for anxiety and OCD spectrum disorders; An empirical review. Journal of Anxiety Disorders, 28, 612– 624. doi 10.1016/j.janxdis.2014.06.008 Brewin, C. R., & Smart, L. (2005). Working memory capacity and suppression of intrusive thoughts. Journal of Behavior Therapy and Experimental Psychiatry, 36, 61– 68. Clark, D. A., Abramowitz, J. S., Alcolado, G. M., Alonso, P., Belloch, A., Bouvard, M., . . . Wong, W. (2014). Part 3. A question of perspective: The association between intrusive thoughts and obsessionality in 11 countries. Journal of Obsessive–compulsive and Related Disorders, 3, 292–299. doi: 10.1016/j.jocrd.2013. 12.006i Clerkin, E. M., & Teachman, B. A. (2011). Training interpretation biases among individuals with symptoms of obsessive compulsive disorder. Journal of Behavior Therapy and Experimental Psychiatry, 42(3), 337–343. doi: 10.1016/j.jbtep.2011.01.003 Corcoran, K. M., & Woody, S. R. (2008). Appraisals of obsessional thoughts in normal samples. Behaviour Research and Therapy, 46(1), 71–83. doi: 10.1016/j.brat.2007.10.007
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Demeter, G., Keresztes, A., Harsanyi, A., Csigo, K., & Racsmany, M. (2014). Obsessed not to forget: Lack of retrievalinduced suppression effect in obsessive–compulsive disorder. Psychiatry Research, 218, 153–160. doi: 10.1016/j.psychres.2014.04.022i Fabricant, L. E., Abramowitz, J. S., Dehlin, J. P., & Twohig, M. P. (2013). A comparison of two brief interventions for obsessional thoughts: Exposure and acceptance. Journal of Cognitive Psychotherapy, 27(3), 195–209. doi: 10.1891/0889-8391.27.3.195 Freeston, M. H., & Ladouceur, R. (1997). What do patients do with their obsessive thoughts? Behaviour Research and Therapy, 35(4), 335–348. doi: 10.1016/S00057967(96)00094-0 Garcia-Soriano, G., Belloch, A., Morillo, C., & Clark, D. A. (2011). Symptom dimensions in obsessive–compulsive disorder: From normal cognitive intrusions to clinical obsessions. Journal of Anxiety Disorders, 25(4), 474– 482. doi: 10.1016/j.janxdis.2010.11.012 Grisham, J. R., Becker, L., Williams, A. D., Whitton, A. E., & Makkar, S. R. (2014). Using cognitive bias modification to deflate responsibility in compulsive checkers. Cognitive Therapy and Research, 38, 505–517. doi: 10.1007/s10608-014-9621-0 Grisham, J. R., & Williams, A. D. (2009). Cognitive control of obsessional thoughts. Behaviour Research and Therapy, 47(5), 395–402. doi: 10.1016/j.brat.2009. 01.014 Grisham, J. R., & Williams, A. D. (2013). Responding to intrusions in obsessive–compulsive disorder: The roles of neuropsychological functioning and beliefs about thoughts. Journal of Behavior Therapy and Experimental Psychiatry, 44(3), 343–350. doi: 10.1016/j.jbtep.2013.01.005 Harsanyi, A., Csigo, K., Rajkai, C., Demeter, G., Nemeth, A., & Racsmany, M. (2014). Two types of impairments in OCD: Obsessions, as problems of thought suppression; compulsions, as behavioral-executive impairment. Psychiatry Research, 215(3), 651–658. doi: 10.1016/j.psychres.2013.11.014 Hayes, S. C., Strosahl, K., & Wilson, K. G. (1999). Acceptance and commitment therapy: An experiential approach to behavior change. New York, NY: Guilford Press. Janeck, A. S., & Calamari, J. E. (1999). Thought suppression in obsessive–compulsive disorder. Cognitive Therapy and Research, 23(5), 497–509. Lambert, A. E., Hu, Y., Magee, J. C., Beadel, J. R., & Teachman, B. A. (2014). Thought suppression across time: Change in frequency and duration of thought recurrence. Journal of Obsessive Compulsive and Related Disorders, 3(1), 21–28. doi: 10.1016/j.jocrd. 2013.11.004 Magee, J. C., Harden, K. P., & Teachman, B. A. (2012). Psychopathology and thought suppression: A quantitative review. Clinical Psychology Review, 32(3), 189–201. doi: 10.1016/j.cpr.2012.01.001 Marcks, B. A., & Woods, D. W. (2005). A comparison of thought suppression to an acceptance-based technique in the management of personal intrusive thoughts: A controlled evaluation. Behaviour Research and Therapy, 43, 433–445.
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Salkovskis, P. M. (1985). Obsessive compulsive problems: A cognitive-behavioural analysis. Behaviour Research and Therapy, 23(5), 571–583. doi: 10.1016/00057967(85)90105-6 Salkovskis, P. M. (1989). Cognitive-behavioural factors and the persisitence of intrusive thoughts in obsessional problems. Behaviour Research and Therapy, 27(6), 677– 682. doi: 10.1016/0005-7967(89)90152-6 Tolin, D. F., Abramowitz, J. S., Przeworski, A., & Foa, E. B. (2002). Thought suppression in obsessive–compulsive disorder. Behaviour Research and Therapy, 40, 1255– 1274. Wahl, K., Huelle, J. O., Zurowski, B., & Kordon, A. (2013). Managing obsessive thoughts during brief exposure: An experimental study comparing mindfulness-based strategies and distraction in obsessive–compulsive disorder. Cognitive Therapy and Research, 37(4), 752– 761. doi: 10.1007/s10608-012-9503-2 Wegner, D. M. (1989). White bears and other unwanted thoughts. New York, NY: Viking/Penguin. Wegner, D. M. (1994). Ironic processes of mental control. Psychological Review, 101(1), 34–52. doi: 10.1037/0033-295X.101.1.34 Wegner, D. M. (2009). How to think, say, or do precisely the worst thing for any occasion. Science, 325, 48–50. doi: 10.1126/science.1167346 Wegner, D. M. (2011). Setting free the bears: Escape from thought suppression. American Psychologist, 66(8), 671–680. doi: 10.1037/a0024985 Wegner, D. M., Erber, R., & Zanakos, S. (1993). Ironic processes in the mental control of mood and mood-related thought. Journal of Personality and Social Psychology, 65(6), 1093–1104. doi: 10.1037/0022-3514.65.6.1093 Wegner, D. M., Schneider, D. J., Carter, S. R., & White, T. L. (1987). Paradoxical effects of thought suppression. Journal of Personality and Social Psychology, 53(1), 5– 13. Wegner, D. M., & Zanakos, S. (1994). Chronic thought suppression. Journal of Personality, 62(4), 615–640. Wilhelm, S., & Steketee, G. (2006). Cognitive therapy for obsessive–compulsive disorder: A guide for professionals. Oakland, CA: New Harbinger. Williams, A. D., & Grisham, J. R. (2013). Cognitive bias modification (CBM) for obsessive compulsive beliefs. BMC Psychiatry, 13(256), 1–9. doi: 10.1186/1471-244X13-256
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