Comparison between eye movement latency and REM sleep parameters in major depression

Alterations of sleep can be observed polysomnographically in approximately 90 percent of depressed patients, Most of the registered sleep abnormalitie s in depression also occur in other psychiatric disorders. Only some types of REM sleep alterations - short REM latency, increase of REM density and s hortening of mean latency of eye movements - were reported as more specific for affective disorders. In the present study polysomnograms of 21 medication free patients with maj or depressive disorder (assessed with a structured interview for DSM-III-R and Hamilton Scale) and 21 healthy controls were analysed. REM latency (LRE M), REM density (RD), latencies of eye movements (LEM) and mean latency of eye movements (M-LEM) were calculated for both groups. Depressed patients ( compared with healthy controls) showed increased RD (38.2% vs. 28.2%, p < 0 .0001), shortened M-LEM (35.7 s vs. 48.3 s, p < 0.04) and shortening of LEM in the 1st (28.9 s vs. 48.9 s, p < 0.007) and 4th (27.0 s vs. 59.1 s, p < 0.043) REM sleep periods. LREM was not shortened significantly in depressiv es (78.5 min vs. 91.3 min, ns). In healthy subjects a negative correlation between M-LEM and Rb was found (rho = -0.47, p < 0.03). Since in the current study depressed patients differed from healthy control s, especially concerning phasic activity, during REM sleep, presented data support the essential role of REM density for the assessment of sleep in de pression. As a quid; and easy manner to compute measurement, M-LEM is sugge sted as additional parameter for the assessment of phasic activity during R EM sleep.