EVIDENCE FOR THE ROLE OF SEROTONIN IN THE REGULATION OF SLOW-WAVE SLEEP IN SCHIZOPHRENIA

Nocturnal sleep data and cerebrospinal fluid (CSF) concentrations of the biogenic amine metabolites were measured in 20 male schizophrenics. Consistent with other reports of a stage 4 sleep deficit in schizophrenia, measures of stage 4 sleep were low relative to normal reference data. Measures of stage 4 sleep in absolute amounts and corrected for total sleep were positively correlated with CSF concentrations of the serotonin metabolite, 5-hydroxyindole acetic acid (5-HIAA). CSF 5-HIAA was also correlated with measures of stage 3 sleep and total sleep time suggesting that serotonin may modulate the amount of slow wave sleep broadly defined and possibly sleep duration. Total stage 4 time was also correlated with the dopamine metabolite HVA; consequently, the specificity of the finding might be limited. Also, in this study, schizophrenia was used as a particular model for stage 4 deficits; however, the association of measures of stage 4 sleep with CSF levels of 5-HIAA is not thought to be specific to schizophrenia.