Cholinergic REM induction test with arecoline in depressed children.

Children with major depressive disorder often fail to exhibit electroencephalographic (EEG) sleep abnormalities similar to those reported in depressed adults. It was hypothesized that a cholinergic rapid eye movement (REM) induction test would contribute to the identification of EEG sleep abnormalities in depressed children. To test this hypothesis, prepubertal children meeting research diagnostic criteria for major depressive disorder (n = 33) and carefully screened healthy control children (n = 15) were enrolled in a 4-day psychobiologic protocol that included 1 night with infusion of arecoline (0.5 mg) during the first non-REM sleep period. Although there had been no significant group differences in baseline sleep measures, results on the arecoline night revealed significantly shorter REM latency in the group of depressed children compared with the control children (mean +/- SD = 105 +/- 51 minutes vs. 140 +/- 46 minutes). The design of the protocol (with an interval break immediately preceding the arecoline night) prevented a direct estimation of arecoline effects within subjects; however, these data provide promising preliminary results regarding cholinergic REM induction tests in childhood depression.