Reported sleep patterns in obsessive compulsive disorder
Previous studies of sleep disturbance in OCD have produced contradictory findings. This may be due to different methodological approaches but may also reflect the fact that many studies have not screened OCD patients for depressive symptoms. This is particularly important since major depression is well known to disrupt sleep. METHOD: The current study examined 94 subjective reports of sleep as measured by the Pittsburgh Sleep Quality Index (PSQI). Twenty-four OCD patients with and without co-morbid depression ( n =12 in each group) were compared with a group of normal subjects ( n =57) and a group of subjects with major depression ( n =13). RESULTS: In general, the OCD patients with co-morbid depression exhibited very similar sleep patterns to the group with major depression. By contrast, those OCD patients without depressive symptoms showed similar sleep patterns to the group of normal subjects. Thus, contrary to some earlier studies, these data suggest that OCD does not generally influence reported sleep patterns unless there is a co-morbid diagnosis. However, a few non-depressed OCD patients did report sleep phase shifting, suggesting that a small proportion may have abnormal sleep parameters. CONCLUSION: Such anomalies may be masked by group analyses and further case studies are therefore warranted to investigate whether such patients exhibit abnormal scores on biological sleep markers.