EFFECTS OF PARA-CHLOROPHENYLALANINE ON SLEEP IN MAN

The effect of depleting brain serotonin with para-chlorophenylalanine (PCP), a selective inhibitor of serotonin synthesis, was studied on the sleep of man. PCP markedly decreased rapid eye movement (REM) sleep. Non-rapid eye movement (NREM) sleep remained either unchanged or was slightly increased. This is in contrast to the reported effect of PCP in other mammals, which is to decrease NREM sleep. In one subject, at a time when PCP had maximally reduced REM sleep, psychological disturbances were produced similar to those previously described in patients taking PCP. These data and the results of other reported investigations suggest that the establishment of any general significance of serotonin in the neuropharmacology of sleep will require detailed investigation of the species in question. © 1969.