Delayed sleep phase in severe obsessive-compulsive disorder: a systematic case-report survey.

INTRODUCTION: To study the prevalence of delayed sleep phase (DSP) in a cohort of inpatients with severe obsessive-compulsive disorder (OCD) and to identify clinical and demographic correlates. METHODS: A systematic retrospective case-report study of consecutive OCD admissions to a specialist inpatient unit from January 1995 to December 2003. Nursing and medical records of sleep, demographic, clinical, and other relevant details were recorded. RESULTS: Of 194 eligible consecutive case reports, 187 were located, and nursing and medical reports of sleep were identified in all 187 (100%). Thirty-three patients (17.6%) fulfilled operationally defined criteria for DSP after exclusion of possible confounding factors. All the patients with DSP were unemployed. Phase-shifted patients were significantly younger than non-shifted patients (P=.019) and reported an earlier age of onset of their OCD (P=.005). There was a non-significant trend toward more severe OCD in the phase-shifted group, but they were not more depressed than their non-shifted counterparts. CONCLUSION: A substantial number of patients with severe, enduring OCD also suffer with DSP, which seems to be specifically linked to OCD as opposed to comorbid depression. Clarification of the etiology within DSP and its interaction with core OCD symptoms on clinical function and disability may identify new treatment targets. To this end, further studies of sleep in OCD using actigraphy and biological measures are indicated.