Impaired off-line memory consolidation in depression

• Published in: European neuropsychopharmacology 2010-08, Vol.20 (8), p.553-561
• Main Authors: Dresler, Martin, Kluge, Michael, Genzel, Lisa, Schüssler, Petra, Steiger, Axel
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aging; Antidepressive Agents - therapeutic use; Depression; Depressive Disorder, Major - drug therapy; Depressive Disorder, Major - physiopathology; Depressive Disorder, Major - psychology; Female; Humans; Internal Medicine; Learning; Male; Memory; Memory Disorders - physiopathology; Memory Disorders - psychology; Middle Aged; Neuropsychological Tests; Practice (Psychology); Psychiatry; Psychomotor Performance; Sex Characteristics; Sleep; Sleep - drug effects; Time Factors; Young Adult
• ISSN: 0924-977X; 1873-7862
• DOI: 10.1016/j.euroneuro.2010.02.002

Abstract Sleep is critically involved in the consolidation of procedural memory. In major depression (MD) and during antidepressant pharmacotherapy, changes in sleep EEG are well documented. Here, we test if off-line motor memory consolidation is impaired in MD. 50 medicated patients with an acute episode of MD, 50 normal controls and 12 patients with a remitted episode of MD were assessed using a sequential finger tapping task before and after a night of sleep. Although depressed patients and control subjects did not differ in practice-dependent learning, healthy subjects showed markedly overnight improvements in tapping performance of 18% while patients failed to show any improvement. This pattern became even more striking when the subjects were divided by an age threshold of 30 years: In the 30+ yrs group the healthy subjects showed 16% overnight increase in motor performance, whereas the patients showed − 10% overnight decrease. In contrast, patients and controls in the ≤ 30 yrs group showed virtually the same motor performance, as well as remitted patients and controls in the 30+ yrs group. In addition, the younger controls showed stronger overnight improvements than the older controls. This pattern might be interpreted as a synergistic interaction between age and depression: Off-line motor memory consolidation is not affected in young patients, but severely impaired in older patients with an acute episode of MD. This impairment seems to recover after remission from depression.