SEATTLE, WA—Cognitive behavioral therapy for insomnia (CBT-I) is effective in treating insomnia that occurs comorbidly with other conditions, regardless of diagnosis or severity of the particular comorbid medical or psychiatric disease, according to results of a meta-analysis presented at SLEEP 2015.
To quantify the effect of CBT-I in studies of patients with insomnia and comorbid disorders, Valerie E. Rogers, PhD, RN, of the University of Maryland School of Nursing, Baltimore, MD, and colleagues searched multiple databases for randomized, controlled trials of CBT-I published in English between January 1985 and February 2014.
Inclusion criteria were at least one medical or psychiatric diagnosis and insomnia, the latter of which was defined by one of the following: trouble initiating or maintaining sleep, or nonrestorative sleep, with significant impairment of daytime function, for at least one month; diagnosis based on the Diagnostic and Statistical Manual of Mental Disorders (DSM), the International Classification of Sleep Disorders (ICSD), or Research Diagnostic Criteria for insomnia disorder; or an Insomnia Severity Index (ISI) score >7. CBT-I components included sleep restriction and stimulus control, had to last at ≥4 sessions, and had to be delivered face-to-face, individually or as group therapy.
A total of 23 studies, 19 of which were unique, met inclusion criteria. Of the 1,379 participants, 33.5% were male and mean age was 53.0 years (±10.0 years). Disorders included chronic pain syndromes, cancer, hearing impairment, chronic obstructive pulmonary disease (COPD), major depressive disorder, alcohol dependence, posttraumatic stress disorder (PTSD), and mixed medical and psychiatric diagnoses.
“There were large pre- to post-treatment effects for the ISI (6 points) and Pittsburgh Sleep Quality Index (3 points),” Dr. Rogers reported. All sleep diary variables improved, including total sleep time (17 minutes, small effect size); sleep latency and wake after sleep onset (both 21 sminutes, moderate effect size); and sleep efficiency (9.3%, large effect size).
;“Change in sleep variables from post-treatment to follow-up, extending from 3 to 18 months, showed trivial effect size,” she noted. Heterogeneity of sleep outcomes between studies was low, except for the ISI, which demonstrated a stronger effect size for individual vs. group treatment (8.2 vs. 2.5 point improvement, respectively).
Dr. Rogers noted that the two strongest components of CBT-I were sleep restriction and stimulus control, and that the ISI was “the most sensitive measure of change.” Improvements endured for up to 18 months of follow-up. These results showed treatment effects that were similar to meta-analyses of CBT-I in older patients, she concluded.