When asked about the drug they had taken the previous day, 11 of the 14 participants (79%) guessed that the highest dosage of Rozerem was the placebo.
Griffiths says the drug may be particularly useful for treating sleep problems in people who have histories of drug abuse.
Older people with sleep problems may also be good candidates, because the mental and physical side effects of other sleep drugs are particularly dangerous for them.
The study, which was funded by Takeda Pharmaceuticals, is published in the October issue of the journal Archives of General Psychiatry.
The Business of Sleep
Sleep has become big business, with sales of prescription insomnia drugs more than doubling in the past five years.
According to the market research group IMS Health, 43.1 million prescriptions for sleep drugs were filled in 2005, compared with 29 million in 2001. That represented a jump in overall sales of brand-name sleep aids from $1.2 billion to $2.8 billion.
Sleep specialist David Neubauer, MD, tells WebMD that Rozerem is a welcome addition to current sleep medications.
"This isn't a drug that is going to help someone sleep all night long," he says. "That is not what it is designed to do. But it can help people who have trouble getting to sleep because of that evening arousal that most of us feel."
Neubauer is the associate director of the Johns Hopkins Sleep Disorders Center. He was not involved in the study.