Effects of total sleep deprivation in major depression: Overnight improvement of mood is accompanied by increased pain sensitivity and augmented pain complaints

Objective: Major depressive disorder (MDD) is associated with more pain complaints and an altered pain perception. To clarify how short-term alleviation of depressive mood is linked to changes in pain processing, the effect of sleep deprivation (SD) on pain and somatosensory thresholds, pain complaints and mood was investigated in MDD patients. Methods: 19 drug-free inpatients with DSM IV diagnosis MDD were investigated for 3 weeks. All patients received cognitive-behavioral therapy and were randomized to obtain either additional SD therapy (6 nights of total SD, separated by recovery sleep) or no SD therapy (control group). Heat/cold pain thresholds, warmth/cold thresholds, measures of current pain complaints and mood were assessed the evening before and the morning after SD as well as before and after a normal night sleep in the control group. Long-term changes of depressive symptomatology were assessed by weekly mood ratings. Results: Both treatment groups improved markedly in mood over the three-week treatment period. SD regularly induced a nearly significant overnight improvement of mood, which was abolished by recovery sleep. Compared with the control condition, SD significantly decreased heat pain thresholds and nearly significantly cold pain thresholds; SD significantly augmented pain complaints the next morning. Conclusions: SD induced differential short-term effects on mood and pain, with the patients being less depressed but more pain vulnerable.