Rapid eye movement (REM) sleep mechanisms may play a role in the pathophysiology of schizophrenia, but results have been inconclusive and studies of sleep in schizophrenia have been deficient in identifying, comparing, and differentiating between subcategories of schizophrenia.
Twenty-nine hospitalized, drug-free schizophrenics were divided into three subgroups—acute, latent, and schizoaffective. The REM intensity measures and REM latency were found to differentiate significantly the schizoaffective group. Sleep-continuity indexes separated the latent and acute groups. Seven patients who later required treatment with tricyclic antidepressants had base line REM latencies significantly lower and hospitalizations significantly more prolonged than the patients who did not require antidepressants.
Sleep measurements may thus identify diagnostic subgroups of schizophrenia as well as predict which schizophrenic patients will have either a prolonged postpsychotic depressive syndrome or a concurrent affective syndrome.