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 inhibitor and a partial 5-HT1A agonist in one molecule in order to combine antidepressive and anxiolytic properties. Objective: We investigated the effects of EMD on the sleep EEG in order to characterize how the complex interaction between these two properties influences the sleep EEG. Methods: We performed 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 hours. Sleep EEG was recorded from 2300 to 0700 hours. Results: After EMD, rapid eye movement (REM) sleep was nearly totally abolished. In the course of 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-third 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 its pharmacological profile, which might lead to adaptive changes suggested to characterize an antidepressive substance.