Investigating unwanted intrusive thoughts in laboratory settings and a natural environment

Unwanted intrusive thoughts (UITs) are essential to research of obsessive-compulsive disorder. This thesis aimed (1) to replicate results of a previous study in which rumination about a UIT maintained the urge to neutralize the UIT, (2) to evaluate the validity of a counter-app method in assessment of UIT frequency, and (3) to examine in what aspects exam-related UITs and related neutralizing behaviors (ER-UITs-N) are analogous to obsessions and compulsions. In study one, we temporarily activated a UIT in N = 105 students and randomly assigned them to rumination about the UIT, rumination about negative mood, or distraction. We assessed distress, urge to neutralize, depressed mood, and UIT frequency. In the next study, we activated a UIT in N = 142 students and assessed the UIT frequency with the counter-app method and three other measures (convergent validity criteria). We also assessed discriminant and predictive validity criteria. Finally, we assessed severity of ER-UITs-N, obsessive-compulsive symptoms, anxiety, distress, urge to neutralize, depressed mood, and stress in N = 29 students using the ecological momentary assessment. Rumination about the UIT maintained the urge to neutralize and distress compared to rumination about negative mood and distraction. Correlations between the counter-app frequency and the validity criteria supported convergent and predictive, but not discriminant, validity of the counter-app method. The severity of ER-UITs-N was positively associated with obsessive-compulsive symptoms, anxiety, distress, urge to neutralize, and stress, but not with depressed mood. Results suggest that rumination about UITs might contribute to their persistence. The counter-app method validly assesses UIT frequency but is not appropriate when the differentiation of frequency from other constructs (e.g., duration) is needed. Finally, the ER-UITs-N seem analogous to obsessions and compulsions in some aspects (e.g., association with distress), but not all (e.g., no relation to depressed mood).