Sleep patterns of two consecutive nights were analyzed in 26 drug-free
patients with Parkinson's disease (PD), who were clinically divided into
depressed (n = 8) and nondepressed (n = 18) groups. Sleep
electroencephalographic (EEG) recording showed significantly shorter rapid
eye movement (REM) latency in depressed PD patients (41.1 +/- 21.7 min)
compared to nondepressed PD patients (129.0 +/- 84.9 min, p less than
0.002). Furthermore, shortened REM latency (less than or equal to 65.0 min)
was observed with significantly more frequency in depressed PD patients (6
out of 8) compared to nondepressed PD patients (4 out of 18, p less than
0.02). The other sleep parameters studied did not differ significantly
between the two groups of patients. Because shortened REM latency is one of
the most reliably documented biological features of major depression, these
findings may be of some importance for understanding the nature of
depression in the course of PD.Abstract Teaser