On the issue of drug washout prior to polysomnographic studies in depressed patients.

In psychoneurobiological studies it is a point of controversy how long psychoactive medication has to be withdrawn to exclude drug effects on the variables to be investigated. In order to answer the question of whether the generally assumed two-week washout of psychoactive medication is sufficient for polysomnographic studies, we computed a post hoc analysis of EEG sleep recordings in 61 newly admitted depressed patients. The results indicate that after a 2-week withdrawal of tricyclic antidepressants and/or benzodiazepines there are no major drug effects on visually scored polysomnograms. In addition, the observations raise the question of whether even a 1-week drug washout may be sufficient to exclude confounding effects of prior psychoactive medication on EEG sleep.