Curing Insomnia to Treat Depression Psychiatrists have long thought that depression causes insomnia, but new research suggests that insomnia can actually precede and contribute to causing depression. The causal link works in both directions. Two small studies have shown that a small amount of cognitive behavioral therapy to treat insomnia, when added to a standard antidepressant pill to treat depression, can make a huge difference in curing both insomnia and depression in many patients. If the results hold up in other studies already underway at major medical centers, this could be the most dramatic advance in treating depression in decades. A study of 66 patients by a team at Ryerson University in Toronto found that the cognitive therapy for insomnia, a brief and less intense form of talk therapy than many psychiatric patients are accustomed to, worked surprisingly well. Some 87 percent of the patients whose insomnia was resolved in four treatment sessions also had their depression symptoms disappear, almost twice the rate of those whose insomnia was not cured. The new results were reported by Benedict Carey in The Times last Tuesday. The brief course of sleep therapy teaches patients to establish a regular wake-up time; get out of bed during waking periods; avoid reading, watching TV or other activities in bed; and eliminate daytime napping, among other tactics. It is distinct from standard sleep advice, like avoiding coffee and strenuous exercise too close to bedtime. The Toronto study is consistent with a 2008 study of 30 patients at Stanford University, all of whom suffered from insomnia and depression and were taking an antidepressant pill. Some 60 percent of those given seven sessions of behavioral therapy for insomnia in addition to the pill recovered fully from their depression, compared with only 33 percent in a control group that got the standard advice for treating sleeplessness. Other studies involving roughly 70 patients each are being conducted at Stanford, Duke University and the University of Pittsburgh, all financed by the National Institute of Mental Health. Those results are expected to be published next year. How these results, if confirmed, will affect clinical practice is uncertain. Most psychiatrists have very little training in dealing with insomnia. As the head of the study at Duke told Mr. Carey, psychiatrists have largely ignored the body's complex circadian cycles. If these promising results are confirmed next year, the N.I.M.H. and leading psychiatric organizations ought to consider ways to bring this cheap and highly effective sleep therapy into widespread clinical use.