THE UNIPOLAR-BIPOLAR DICHOTOMY AND THE RESPONSE TO SLEEP-DEPRIVATION

Fifty-one inpatients affected by a major depressive episode were divid ed into four groups according to mood disorder diagnosis and previous clinical history (bipolar disorder type I; bipolar disorder type II; m ajor depressive disorder with at least three previous depressive episo des; and single depressive episode patients) and administered three co nsecutive total sleep deprivation (TSD) cycles. Mood changes were rate d with a reduced version of the Hamilton Depression Rating Scale and w ith self-administered visual analogue scales. TSD caused better clinic al effects in bipolar and single-episode patients; in particular, unip olar patients lacked effects in perceived mood after the first TSD and showed worse Hamilton ratings in respect to the other groups after th e three TSD treatments. Discriminant function analysis could correctly classify 80% of bipolar patients, post hoc, based on TSD response. Fu rther researches on the clinical efficacy of TSD must take into accoun t the heterogeneity of depression and of its biological substrate. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.