Distinct temporal pattern of the effects of the combined serotonin-reuptake inhibitor and 5-HT1A agonist EMD 68843 on the sleep EEG in healthy men

Rationale: EMD 68843 (EMD) has properties of a serotonin (5-HT)-reuptake in hibitor and a partial 5-HT1A agonist in one molecule in order to combine an tidepressive and anxiolytic properties. Objective: We investigated the effe cts of EMD on the sleep EEG in order to characterize how the complex intera ction between these two properties influences the sleep EEG. Methods: We pe rformed a randomized crossover study in ten young normal male controls (20- 30 years), receiving a single dose of 20 mg EMD or placebo orally at 2100 h ours. Sleep EEG was recorded from 2300 to 0700 hours. Results: After EMD, r apid eye movement (REM) sleep was nearly totally abolished. In the course o f the night other effects on the sleep EEG occurred in distinct intervals. Slow wave sleep and EEG delta power increased in the first and third one-th ird of the night, whereas wakefulness was enhanced in the second and third one-third of the night. Conclusion: The sleep EEG effects of EMD fit with i ts pharmacological profile, which might lead to adaptive changes suggested to characterize an antidepressive substance.