Sleep propensity at daytime as assessed by Multiple Sleep Latency Tests (MSLT) in patients with schizophrenia increases with clozapine and olanzapine

In conclusion, mean sleep latency was > 36% longer (i.e. sleep propensity was lower) in untreated patients with schizophrenia than in healthy subjects previously consistently reported. Furthermore, clozapine and olanzapine increased sleep propensity in schizophrenic patients. A minority of patients reported subjective sleepiness.