Melatonin lag for jet travelers.

Many people whose long-distance flights leave them grounded with jet lag believe they can soar back into action by taking melatonin pills (5/13/95, p. 300) for a few days. Any dent in jet lag attributable to melatonin, however, may stem from a person's expectations that the hormone will provide relief, not from its physiological effects, a new study finds.

After taking a plane trip to Norway from New York City, people receiving melatonin experienced just as much jet lag as fellow travelers given placebos, says a group led by psychiatrist Robert L. Spitzer of Columbia University in New York City. The researchers' investigation represents the largest controlled trial to date of melatonin use for jet lag.

Several prior studies found that melatonin dampens jet lag more than placebos do, although each used a different jet lag measure. To gauge the severity of jet lag, Spitzer and his colleagues devised a self-report survey that they hope will catch on with other researchers. It focuses on fatigue, daytime sleepiness, loss of concentration and alertness, memory troubles, weakness, clumsiness, lethargy, and light-headedness.

Norwegian physicians who had visited New York City for 5 days filled out the jet-lag survey soon after their plane landed back in Oslo and again each day for the next 6 days. The time difference between Oslo and the Big Apple is 6 hours.

On their New York departure day and for the next 5 days, the 257 participants received capsules containing an inactive substance, a small melatonin dose, or a large melatonin dose. The men and women, average age 44, swallowed these capsules at bedtime, except for some in the low-dose group who took them 1 hour earlier each successive evening of the study.

To make it more difficult for volunteers to guess whether they were getting melatonin, they all took a placebo capsule a few hours before gulping down their assigned treatments.

Most of the volunteers in each treatment group endured a blast of jet lag on their first day home, followed by progressive improvement, the scientists report in the September AMERICAN JOURNAL OF PSYCHIATRY. Neither of the melatonin treatments eased the time transition better than placebo use.

It remains unclear whether jet lag arises primarily because of an out-of-sync biological clock, stress and sleep loss away from home, or other factors, Spitzer's group holds.