First-night effect of melatonin treatment in patients with chronic schizophrenia

The first-night effect (FNE) is the tendency for individuals to sleep worse than normal during their first night of polysomnographic sleep evaluation. FNE reflects the adaptive increase of alertness and perhaps the stress res ulting from an unfamiliar sleeping environment. This effect is usually abse nt in patients with chronic schizophrenia. Melatonin (N-acetyl-5-methoxy-tr yptamine), the hormone secreted by the pineal gland at night, has been foun d to improve sleep in elderly patients with insomnia and recently in patien ts with chronic schizophrenia. The authors used FNE as a marker to explore the neurobehavioral responses of patients with chronic schizophrenia to mel atonin treatment. In a randomized, double-blind, crossover trial, 14 patien ts with chronic schizophrenia were administered melatonin (2 mg in a contro lled-release formulation) or placebo for 3 weeks with a 1-week washout betw een treatment periods. Polysomnography was performed during the last two co nsecutive nights of each treatment period. The following significant FNEs w ere observed with melatonin treatment: (1) rapid eye movement sleep latency was longer; (2) sleep efficiency was lower; and (3) the duration of wakefu lness during sleep was lower on the first night than on the second night. T hese effects were not found when the patients received a placebo. The FNE w as manifested regardless of whether melatonin was administered before or af ter the placebo treatment period. For the first time, these results show th at melatonin treatment exaggerates FNE in patients with chronic schizophren ia, thereby suggesting an improved ability of these patients to mobilize al ertness in unfamiliar surroundings.