The Superiority of Danger Ideation Reduction Therapy (DIRT) Over Exposure and Response Prevention (ERP) in Treating Compulsive Washing

The present study involved the random allocation of 22 obsessive-compulsive (OC) washer/cleaners to one of two treatment conditions: Danger Ideation Reduction Therapy (DIRT), or Exposure and Response Prevention (ERP). Participants received 12 1-hour individual clinical sessions and were assessed at pretreatment, posttreatment and at a 6-month follow-up with a battery of 17 measures assessing core obsessive-compulsive disorder (OCD) symptomatology, depression, stress, general anxiety, disease expectancy and perceived responsibility. DIRT subjects experienced significantly greater before to after-treatment reductions in symptomatology on six outcome measures. On 10 of the remaining 11 measures, posttreatment mean scores were lower in the DIRT condition than in the ERP condition, though differences between groups failed to reach significance. Of note, on 3 of the 17 measures, DIRT subjects experienced significantly greater posttreatment to follow-up symptom reduction. Finally, and most importantly, symptom change (regardless of treatment condition) was shown to significantly correlate with change in threat or disease expectancy across the trial. No relationships were found between improvements in perceived responsibility and any of the dependent variables. The findings suggest that DIRT and ERP may be working by reducing specific beliefs in threat; the former treatment being more effective in producing such change than the latter.