U.S. PSYCH: Insomnia Treatment Boosts Antidepressant Efficacy

SAN FRANCISCO, April 25 -- A significant number of patients with major depression also suffer from chronic insomnia that hampers recovery, a sleep expert said here.

"Treating the insomnia pharmacologically or behaviorally can improve outcomes in depression," said Christopher L. Drake, Ph.D., of the Henry Ford Hospital Sleep Disorders and Research Center in Detroit.

The prevalence of insomnia comorbid with psychiatric disorders is 40.4%, with major depression accounting for about 15%, he said in a presentation at the U.S. Psychiatric and Mental Health Congress regional extension meeting here.

Depression treatment itself may increase the risk of sleep disturbance. A 2002 study in the Journal of Clinical Psychopharmacology found that 15% to 25% of patients on a selective serotonin reuptake inhibitor antidepressant had insomnia as an adverse event while 15% to 20% reported somnolence during double-blind acute treatment.

"Insomnia is the most common 'residual' symptom in non-remitted depression," Dr. Drake said, so there may be some independence between insomnia and depression. But, residual symptoms such as insomnia predict time to relapse or recurrence of depression among responders.

Poor sleep quality is also predictive of suicidal behavior.

However, most insomniacs do not seek treatment for the condition. In a study by the Gallup Organization, only 6% of individuals with insomnia had seen a physician with sleep problems as the primary reason for consultation while 24% had insomnia as a secondary reason for consultation.

Sleep aids do appear to work for patients with major depression, though. A 1999 study of zolpidem (Ambien) found it improved time to sleep onset and waking after sleep onset among patients with stable SSRI-treated depression.

Furthermore, treating insomnia in patients with major depressive disorder improves antidepressant response, Dr. Drake said.

In a study published in the journal Biological Psychiatry in 2006, patients who took both the sleep aid eszopiclone (Lunesta) and fluoxetine (Prozac) had an antidepressant response about two weeks earlier than patients treated with fluoxetine alone (P=0.0002).

Eszopiclone and fluoxetine together also significantly improved on both the overall Hamilton depression scores and Hamilton scores excluding insomnia-related items compared to fluoxetine alone. Significantly more patients treated for both depression and insomnia reached remission as well (42% versus 32.8%, P=0.03).

While there are few controlled trials of treatment of comorbid insomnia among patients with other psychiatric and medical conditions, there is some evidence of benefit for those with mixed psychiatric conditions, alcoholism, post-traumatic stress disorder, and Alzheimer's disease, according to a study in the journal Sleep Medicine Reviews last year.