How does thought suppression impact upon beliefs about uncontrollability of worry?

According to Wells' metacognitive model of generalised anxiety disorder (GAD; [Wells, A. (1995). Meta-cognition and worry: A cognitive model of generalised anxiety disorder. Behavioural and Cognitive Psychotherapy, 23, 301-320]), GAD patients attempt to suppress intrusions that trigger worry. Wells postulates that these attempts are rarely effective and may increase the frequency of worry triggers. These apparent failures are interpreted as evidence for loss of mental control, thereby exacerbating beliefs about worry uncontrollability. The current study tested these predictions. Sixty-two high worriers completed a naturalistic experiment comprising two sessions separated by 1 week. In Session 1, participants recorded their beliefs about worry in general, including its uncontrollability. They then selected a current worry and recorded how often it came to mind over the following week. The Suppression group (N=32) suppressed their chosen worry during the week. The Mention group (N=30) simply monitored its occurrence. In Session 2, Session 1 measures were repeated. Contrary to prediction, the Suppression group reported a significant increase in worry controllability in general. No shift was demonstrated by the Mention group. In addition, relative to the Mention group, the Suppression group reported more success at suppressing their chosen worries, spent less time thinking about them, and found them more controllable and less distressing. Findings are discussed within the context of Wells' model.