Jet lag: Clinical features, validation of a new syndrome-specific scale, and lack of response to melatonin in a randomized, double-blind trial

Objective: The goals of this study were to validate a new rating scale for measuring severity of jet lag and to compare the efficacy of contrasting melatonin regimens to alleviate jet lag. Method: This was a randomized, double-blind trial of placebo and three alternative regimens of melatonin (5.0 mg at bedtime, 0.5 mg at bedtime, and 0.5 mg taken on a shifting schedule) for jet lag. The subjects were 257 Norwegian physicians who had visited New York for 5 days. Jet lag ratings were made on the day of travel from New York back to Oslo (6 hours eastward) and for the next 6 days in Norway. The main outcome measures were scale and item scores from a new, syndrome-specific instrument, the Columbia Jet Lag Scale, that identifies prominent daytime symptoms of jet lag distress. Results: There was a marked increase in total jet lag score in all four treatment groups on the first day at home, followed by progressive improvement over the next 5 days. However, there were no significant group differences or group-by-time interactions. In addition, there was no group effect for sleep onset, time of awakening, hours slept, or hours napping. Ratings on a summary jet lag item were highly correlated with total jet lag scores (from a low of r=0.54 on the day of travel to a high of r=0.80 on day 3). The internal consistency of the total jet lag score was high on each day of the study. Conclusions: The use of melatonin for preventing jet lag needs further study.