Rebound effects following deliberate thought suppression: Does PTSD make a difference?

This study was designed to examine the effects of deliberate suppression of trauma-related thoughts in 44 individuals who were diagnosed with posttraumatic stress disorder (PTSD+) and 26 individuals who were not (PTSD-) following a motor vehicle accident (MVA). In an effort to resolve discrepancies in the literature, the PTSD- group was selected from the same help-seeking population as the patient group. Measures included the percentage of MVA-related thoughts, mood, perceived controllability of thoughts, and physiological arousal (heart rate, skin conductance, and two measures of facial EMG). Contrary to hypothesis, both PTSD+ and PTSD- groups showed a rebound in trauma-related thoughts following deliberate thought suppression. This rebound was associated with increases in negative affect, anxiety, and distress and diminished perceptions of controllability over thoughts. Examination of the physiological measures did not mirror the pattern noted for trauma-related thoughts, although the data suggest that suppression was associated with higher levels of frontalis EMG. The current study indicates that help-seeking individuals who are distressed about their psychological state following a serious MVA will show a rebound in MVA-related thoughts, irrespective of PTSD diagnosis. Implications for the study of thought suppression as a potential maintaining factor for trauma-related problems are discussed, with suggestions for future research.