Objective: A number of pharmacologic studies have documented that insomnia is among the most commonly reported residual symptoms after remission from depression. Residual symptoms after remission are particularly relevant because these symptoms confer greater risk for subsequent depression. This study was the first to date to examine residual insomnia after cognitive-behavioral therapy (CBT) for depression and to compare CBT with pharmacotherapy for depression on residual insomnia rates.
Method: This naturalistic study examined rates of posttreatment insomnia complaints in patients (N = 94) who had been diagnosed with major depressive disorder (MDD), according to DSM-IV criteria, and who remitted from MDD after completing at least 20 weeks of either CBT or pharmacotherapy at an outpatient clinic specializing in mood disorders. Participants were randomly assigned to the treatment conditions, but only the data from those who completed treatment and remitted were analyzed. Primary outcome measure was the 17-item Hamilton Rating Scale for Depression. Data were collected from October 1, 1999, to September 23, 2003. Groups were compared using a chi(2) for nominal data.
Results: The rate of posttreatment insomnia was 22% for sleep-onset insomnia, 26% for sleep-maintenance insomnia, and 17% for early morning awakenings, and the rates did not statistically differ across the 2 treatment groups.
Conclusion: Although CBT and pharmacotherapy effectively addressed depression in these patients and addressed insomnia symptoms for many, there were a number of patients with residual insomnia. Whereas there appears to be no difference between CBT and pharmacotherapy with regard to rates of residual insomnia, the rates of such insomnia remaining after these treatments suggest that adjunctive sleep treatment to specifically address insomnia may be necessary for some MDD patients.