Chronic alcohol consumption blunts the biological clock’s ability to synchronize daily activities to light, disrupts natural activity patterns and continues to affect the body’s clock (circadian rhythm), even days after the drinking ends, according to a new study with hamsters.

A team of researchers from Monash University, The Brigham and Women's Hospital (Boston), Harvard Medical School and Vanda Pharmaceuticals has found a new drug with the potential to alleviate jet lag and sleep disorders caused by shift work.

The circadian rhythm that quietly pulses inside us all, guiding our daily cycle from sleep to wakefulness and back to sleep again, may be doing much more than just that simple metronomic task, according to Stanford researchers.

Growing evidence indicates that exposure to irregular patterns of light and darkness can cause the human circadian system to fall out of synchrony with the 24-hour solar day, negatively affecting human health — but scientists have been unable to effectively study the relationship between circadian disruptions and human maladies.

As anyone who has suffered from jetlag knows, we have internal clocks that tell us when to sleep and wake, and we can be miserable when these are disrupted.

The use of daytime bright lighting to improve the circadian rhythm of elderly persons was associated with modest improvement in symptoms of dementia, and the addition of the use of melatonin resulted in improved sleep, according to a study in the June 11 issue of JAMA.

The magnitude of circadian advantage influences the outcome of Major League Baseball (MLB) games in that teams with greater circadian advantage are more likely to win, according to a research abstract that will be presented on Tuesday at SLEEP 2008, the 22nd Annual Meeting of the Associated Professional Sleep Societies (APSS).

Like a wristwatch that needs to be wound daily for accurate time-telling, the human circadian system — the biological cycles that repeat approximately every 24 hours — requires daily light exposure to the eye’s retina to remain synchronized with the solar day.

Why do rats live faster and die younger than humans? A newly discovered biological clock provides tantalizing clues.

Bipolar disorder, commonly known as manic-depressive disorder, is highly influenced by the circadian system – the body’s internal clock – and a specific kind of psychotherapy may help decrease irregularities in the circadian system that can trigger key symptoms of bipolar disorder, according to a study presented today at the American College of Neuropsychopharmacology (ACNP) annual meeting.

When people living in many parts of the world move their clocks forward one hour in the spring in observance of daylight saving time (DST), their bodies’ internal, daily rhythms don’t adjust with them, reports a new study appearing online on October 25th in Current Biology, a publication of Cell Press.

Massachusetts General Hospital (MGH) clinical researchers, in collaboration with basic scientists from the University of California, Irvine (UC Irvine) have identified a new molecular pathway required for normal development of the reproductive, olfactory and circadian systems in both humans and mice.