A protein missing in people suffering from narcolepsy could be the key to helping insomniacs sleep, according to a study published Sunday.

A team of researchers led by Francois Jenck of Swiss drug company Actelion Pharmaceuticals found blocking brain receptors to the blood peptide orexin promoted sleep in rats, dogs and humans, according to a paper in the online issue of Nature Medicine.

Orexin, or hypocretin, is absent in the brain of people suffering from narcolepsy, the disorder that causes some people to drop off into sleep.

The researchers said they have developed a drug that blocks the receptors in the brain that respond to orexin/hypocretin. A spokesman for Actelion said the company hopes to decide this year whether to pursue another, more thorough, study that would be the final step before seeking government approval.

Narcolepsy victims also experience cataplexy, a waking condition that involves the loss of muscle control, though Jenck said the tests have not shown any instances of cataplexy.

Dr. Thomas Scammell, an assistant professor of neurology at Harvard University and not a member of the research team, said the results were promising but cautioned subsequent studies are needed to determine the quality of the sleep experienced.

One in seven Canadians aged 15 or older — or 3.3 million people — suffer from some form of insomnia, according to information from the 2002 Canadian Community Health Survey. The College of Family Physicians of Canada says 30 to 40 per cent of adults suffer from insomnia.

With files from the Associated Press