[Melatonin and schizophrenia]

Many research studies have been conducted with melatonin, a pineal hormone, in psychiatry. Studies with melatonin in schizophrenic patients are rare. Blood plasma samples were drawn at 24 hours and 12 hours in 23 schizophrenic subjects and 26 controls, during the same season. Plasma melatonin levels were obtained using a specific radioimmunoassay technique. The 24 hours levels significant decreased in schizophrenic patients compared with controls (p less than 0.01). Methodology, specificity of results and concomitant study of cortisol levels are discussed.