A randomized controlled trial depicted that the addition of cognitive behavioral therapy to standard care leads to improvement in sleep efficiency, severity of insomnia, quality of life, and symptom score of depression. In an outpatient population with moderate to severe depression and comorbid insomnia, Henny Dyrberg et al. sought to investigate the impact of cognitive behavioral therapy for insomnia on depressive symptomatology and sleep characteristics.

Overall, 47 individuals were randomly assigned to receive one weekly session of either standard care or cognitive behavioral therapy for insomnia for 6 weeks. The treatment was a hybrid between group therapy and individual therapy. In a group setting, sleep scheduling could be particularly difficult since depressed individuals would require extra encouragement to follow treatment guidelines.

The Insomnia Severity Index (ISI) served as the major endpoint indicator. The World Health Organization Questionnaire for Quality of Life and polysomnography, the Hamilton Depression Rating Scale for depression  (HAM-D17), the Dysfunctional Beliefs and Attitudes about Sleep Questionnaire, and sleep diary data were the secondary endpoints ascertained.

Cognitive behavioral therapy improved sleep efficiency (mean standard error [SE] 71.6 to 83.4). Furthermore, it substantially decreased wake after sleep onset (mean 54.7 minutes to 19.0 minutes) and insomnia severity index (mean ISI 20.6 to 12.1) as contrasted to standard care. There was no alteration in sleep onset latency and total sleep time. Analyses of the symptom dimensions and other rating scales corroborated the findings.

The symptom score of depression (HAM-D17), quality of life (WHO-5), the severity of insomnia (ISI), and efficiency of sleep were significantly improved with CBT-I use in patients with chronic insomnia and severe depression.