Health Briefs / DMN

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Monday | January 7, 2002

Health briefs

01/07/2002

Study finds human clock needs days of 24 hours

Researchers describe it as a world-class case of jet lag, only the problem occurs not on this world but off it. The human clock, they found, cannot adjust to days that deviate from 24 hours – a problem for astronauts on extended missions. The study was paid for by NASA and the National Space Biomedical Research Institute and published in a recent issue of the Proceedings of the National Academy of Sciences.

The researchers found that even slight shifts in the length of the day posed problems. It is already a problem on space shuttle missions, where the crews typically operate on days of 23 1/2 hours. And it poses challenges if astronauts are ever sent to Mars, where the days are a little over 24 1/2 hours.

One author, Dr. P. Jr. of Brigham and Women's Hospital, the Harvard affiliate in Boston where the research was done, said the failure of the human body clock to adjust led to fatigue. And that can raise safety issues.

The research participants remained in low-light settings, like those on spacecraft, for as long as 55 days and maintained fixed schedules of work and rest geared to days of three differing lengths.

Even in the low-light conditions, they found, the volunteers on a 24-hour day had normal levels of a hormone that regulates sleep, melatonin. The two other groups were never able to bring their melatonin levels into sync with their new schedules, and they experienced sleep problems.

Any solution they come up with, the researchers said, may also be useful on Earth for travelers suffering from jet lag and for workers with difficult shifts.

New York Times News Service

Reports note benefits of newer antipsychotics

Patients taking some of the newer antipsychotics appear more likely to stick with their medicine, and less likely to suffer relapse, than patients taking older types of such drugs, researchers report. In one study, scientists at the University of California, San Diego examined a year's pharmacy refill records for 288 veterans with psychotic disorders. Patients taking certain newer, so-called atypical antipsychotic drugs were without medicine for an average of four days per month, compared with seven days for patients on some older, "typical" antipsychotics. The findings appear this month in the American Journal of Psychiatry.

The researchers, noting that even patients on the newer drugs often did not adhere to medicine schedules, urged that programs be developed to help psychosis patients stick with their medicine.

In the second study, scientists led by Csernansky of Washington University School of Medicine in St. Louis assigned nearly 400 patients with schizophrenia or schizo-affective disorder to take the newer antipsychotic Risperdal or the older drug Haldol for at least a year. In the Risperdal group, 25.4 percent suffered a relapse, compared with 39.9 percent in the Haldol group. Among those on Risperdal, 44.1 percent discontinued treatment for reasons other than relapse, while 52.7 percent on Haldol stopped.

The study, sponsored by the research foundation for Risperdal maker Janssen Pharmaceutica, was reported last week in The New England Journal of Medicine.