As it has happened so often in medical history, a drug to treat one health problem may have significant positive effects on another health condition. This time it appears that a medication used to treat a variety of sleep problems is bringing hope to those who suffer with bipolar disorder.

The drug is Modafinil, and is nicknamed 'the wake-up pill' for its ability to treat those who suffer from sleep apnea, shift-work disorder and the excessive sleepiness that comes from narcolepsy. While medical experts aren't quite sure why it works on the depressive episodes of bipolar disorder, it really shouldn't come as a big surprise.

Bipolar disorder, according to some medical experts, is associated with disruptive patterns in a person's circadian clock, the timing mechanism of the body which allows us to follow a day-night pattern. That's why when a person suffering from bipolar disorder loses sleep, it very often sets off an episode.

A study, conducted at five major universities in the United States and Europe, discovered that Modafinil, appeared effective at controlling the depressive symptoms associated with bipolar disorder. Of 85 people suffering from bipolar disorder who were involved in this study, 44 percent reported improved symptoms in the depressive phase of theirbipolar disorder.

The study's author, and director of the Mayo Clinic Mood Disorders Clinic and Research Program, is very pleased with the potential this holds for those who suffer with bipolar disorder. 'There are very few treatments for the depressive phase ofbipolar disorder,' explained Dr. Mark Frye. '[T]here is an urgent need to evaluate potential new therapeutics.' The study was conducted in 2005 when Frye was associated with the University of California at Los Angeles. The study was published August 2007 in the American Journal of Psychiatry.

Frye said that mood stabilizers, the traditional treatment for those withbipolar disorder, are much better at treating the mania phase of the mental illness. 'But the depressive phase of [bipolar disorder],' he added, 'is far more common.'