Insomnia's cure proves elusive for researchers

Washington -- Helping patients attain a good night's rest is a goal for many physicians, but what to recommend is not always clear.

Adequate sleep seems to be regularly out of reach for an estimated 40 million to 70 million Americans and effective treatments are elusive, said a panel of sleep experts convened by the National Institutes of Health on June 13-15.

Insomnia is the most commonly reported sleep problem in the industrialized world, and many with the problem often turn to unproven medications to gain some rest, testified Manisha Witmans, MD, who is a sleep medicine specialist and assistant professor at the University of Alberta in Canada.

A sleep problem can be a disorder on its own or it can be a symptom of something else, most commonly depression. Lack of sleep is associated with mood disturbances, difficulties with concentration and memory, and some cardiovascular, pulmonary and gastrointestinal disorders. It has even been implicated in the rising levels of obesity.

"We know that patients can struggle for years with insomnia, and we know that they use a variety of over-the-counter and prescription drugs to deal with it," said Alan Leshner, PhD, chief executive officer of the American Assn. for the Advancement of Science, and the chair of the panel. "Unfortunately, we found insufficient evidence to recommend most of these treatments for long-term use."

Vaughn McCall, MD, professor and chair of the Psychiatry Dept. at Wake Forest University Baptist Medical Center in Winston-Salem, N.C., told the panel he could find no evidence that randomized controlled clinical trials had ever been conducted for five of the 10 pharmaceuticals prescribed most often for chronic insomnia.

None of the 10 are currently approved for insomnia, though all have been approved by the Food and Drug Administration as antidepressants, antipsychotics or sedatives, he noted.

The antidepressant trazodone is the most often prescribed first-line therapy, yet Dr. McCall found only one study showing that it was superior to placebo in the first week of treatment for insomnia and no better than placebo in the second week. For patients already on antidepressants, there were two small, short-term trials that showed the use of trazodone was better than placebo.

Panelists also expressed concern about many of the other drugs used to treat insomnia, including antihistamines, which are relied on by many but have not been approved for treating insomnia and could cause lingering daytime sleepiness.

Many with insomnia also self-medicate with alcohol, according to the panel, despite the fact that the risks of excess alcohol consumption outweigh any sleep benefit.

The panel also found little to recommend melatonin or herbal therapies as sleep remedies.

Dispelling the myths that such treatments work likely will prove a difficult challenge, said panelist Sean M. Caples, DO, assistant professor of medicine at the Mayo Clinic in Rochester, Minn.

The concern is that those treatments could have serious medical consequences of their own, Dr. Leshner said. Without the benefit of good research to establish their efficacy, it's almost impossible for a physician or patient to do the cost-benefit analysis necessary to determine whether to prescribe, recommend or use a particular medication, he noted.

Sleep remedies

Despite the gloomy news about most treatment options, the panel did find a few effective approaches. Among them: cognitive-behavioral therapy and the newer benzodiazepine receptor agonist medications. Neither, however, is as widely used as it could be, the panel found.

While cognitive-behavioral therapy is effective and has no side effects, there are few trained sleep specialists who can administer such treatment, said Jack Edinger, PhD, a clinical professor in the department of psychiatry at Duke University in Durham, N.C.

Behavioral methods could include instruction in relaxation techniques, while cognitive therapy seeks to eliminate any anxiety-producing beliefs about sleep, Dr. Edinger said.

Research has shown that the non-benzodiazepines, or hypnotics, have fewer and less severe adverse effects than other medications and show promise for long-term use, according to the panel. But physicians aren't prescribing them as often as they could.

The fact that they are controlled substances could be one reason for this reluctance, suggested panel member James Kvale, MD, professor at the University of Texas Health Science Center's Dept. of Family and Community Medicine.

Physicians might believe that they would be more vulnerable to scrutiny by authorities if they prescribe them too often, Dr. Kvale said.

Panel members found so many gaps in the research on insomnia that they called for a wide range of studies to address the causes, mechanisms, consequences and the course of chronic insomnia.

The National Sleep Foundation commended the panel's findings.

"Its report was well-balanced and did an excellent job of reviewing existing therapies," said James K. Walsh, PhD, president of the National Sleep Foundation and a senior scientist and executive director of the Sleep Medicine and Research Center at St. John's/St. Luke's Hospitals in St. Louis. Dr. Walsh also testified before the panel.