CAN MELATONIN IMPROVE SHIFT WORKERS TOLERANCE OF THE NIGHT-SHIFT - SOME PRELIMINARY FINDINGS

The pineal hormone melatonin is potentially useful in the treatment of disorders, especially sleep disorders, associated with circadian rhyt hm disturbance. We have examined its effects on sleep, mood, and behav iour in a double-blind, placebo-controlled study of a small group of p olice officers working spans of seven successive night shifts. Compare d to placebo, and to no treatment, melatonin (5 mg) taken at the desir ed bedtime improved problems related to sleep and increased alertness during working hours, especially during the early morning. In letter-t arget performance tests visual search speed and accuracy were either u nchanged or slightly improved. Memory scanning speed and perception of mental load were adversely affected. This preliminary study suggests that melatonin has beneficial effects on sleep and alertness, but that its effects on performance need careful evaluation.