Relationship between mood improvement and sleep changes with acute nicotine administration in non-smoking major depressed patients.

Background: Acute administration of nicotine patches produced rapid eye movement sleep (REM) increases in non-smoking major depressed patients as well as clinical improvement in mood. Antidepressant effect was also observed after four continuous days of nicotine administration. The main goal of the present study was to observe the relationship between changes in REM sleep variables and mood in non-smoking major depressed patients.

Method: Fifteen major depressed patients (DSM-III-R) were studied under the following sleep laboratory conditions: habituation, two all-night polysomnography recordings, the first one was baseline and the second one was nicotine patch (17.5 mg) night. Patients should had a HAMD-21 punctuation equal or above 18 points for to be admitted in the study. A short HAMD (10 items), and side effect scale was used daily during the two recording nights.

Results: A significant increase in REM sleep time and reduction in sleep stage II was observed when patients were on nicotine patches. Ten patients improved (reduction of 30% in the HAMD of 10 items), the morning after nicotine. All of them also increased REM sleep time above their baseline. Eight patients from the one with significant improvement had a short REM sleep latency below 60 minutes at baseline.

Conclusions: The hypersensitivity of the cholinergic system may be related to the REM sleep enhancement effect observed in some of the patients when received nicotine and also related to the clinical improvement. The role of the acetylcholine in depression could be explored with the administration of transdermal nicotine patches.