The impact of thought suppression outside the laboratory: effects on thought frequency, dismissability and distress in an obsessional cohort

Background: Thought suppression is a form of mental control implicated in the development and maintenance of Obsessive Compulsive Disorder (OCD). Aims: To examine the impact of thought suppression on intrusive thought frequency, distress and thought dismissability in a non-clinical, high obsessional cohort. Method: Fifty two non-clinical participants, screened for obsessional intrusions, completed a thought suppression paradigm over one week. Participants were randomly allocated to a suppression (N=25) or mention (N=27) group and completed three experimental phases, each lasting two days: (1) baseline monitoring, (2) experimental instruction (suppress or mention), and (3) monitoring. Participants recorded target thought occurrences and daily ratings of thought frequency, duration, dismissability, anxiety and unacceptability. Results: The suppression group experienced reduced thought frequency during phases two and three relative to baseline. Lower levels of anxiety were reported in the suppression group relative to the mention group at phases two and three. Suppression instructions had no impact on ratings of dismissability or unacceptability of intrusive thoughts. Conclusions: Results do not support the view that thought suppression leads to an immediate or delayed increase in thought frequency. There was no evidence that thought suppression led to any other detrimental effects. Theoretical and clinical implications are considered