Imagery Rescripting for Obsessive Compulsive Disorder and Body Dysmorphic Disorder: a Multiple-Baseline Single-Case Experimental Design.

In a multiple baseline case series study the effectiveness of Imagery Rescripting (ImRs) as a treatment for Body Dysmorphic Disorder (BDD) and Obsessive Compulsive Disorder (OCD) will be researched. 18 participants with OCD and 18 participants with BDD will be randomized to a waiting list with variable length between 3-8 weeks. After this participants will enter a 1-3 session for preparation followed by 12 sessions with ImRs, given twice-weekly. Follow up assessment will take place 6 weeks after ending treatment. Primary outcome is schema of core beliefs and OCD or BDD symptoms, operationalized by daily measures with visual analogue scales. Also 4 times the investigator measures the OCD or BDD symptoms with the Yale Brown Obsessive Compulsive Scale (Y-BOCS), depression with the Hamilton Depression Rating Scale (HDRS) and 3 times the schema and mode questionnaires with the Young Schema Questionnaire (YSQ) and de Schema Mode Inventory (SMI). The hypothesis is that the primary outcomes will reduce more during the intervention phase compared to the baseline phase and remain stable or even further improve in the follow-up phase. For the secondary outcomes the investigator hypothesized a decrease in depressive symptoms, a decrease in the emotions guilt or shame and first an increase in sadness, fear and angriness followed by an decrease. The largest effect is expected from pre- to post treatment, with a relative stable little change during baseline and follow-up.

Results will be analyzed using visual inspection, repeated measures ANOVA and multilevel analysis, pooling the effects of the individual cases. Finally, participants will be interviewed post treatment about their experiences during treatment.