Sleep disturbance isn’t merely a consequence of pain, says Johns Hopkins sleep researcher Michael Smith. “Insomnia makes pain worse.” This is especially true, he adds, in patients with knee osteoarthritis (OA), 81 percent of whom report having trouble maintaining sleep.

A recent study Smith spearheaded, however, shows that cognitive-behavioral therapy may improve both insomnia and clinical pain. Published in the May 2015 issue of Arthritis and Rheumatology, the study is the largest to date examining the effectiveness of cognitive behavioral therapy as a sole treatment for insomnia related to chronic pain and the only study that’s included polysomnography—tests to diagnose sleep disorders–among the outcome measures.

Smith and his colleagues conducted the randomized, double-blind, active placebo-controlled clinical trial with 208 participants in four groups: people with insomnia and OA; people with joint problems only; people with insomnia only; and healthy adults with neither disorder. Seventy-two percent of the participants were women.

The active treatment Smith and colleagues used was a standardized cognitive behavioral therapy intervention that included sleep restriction therapy, stimulus control therapy, cognitive therapy for insomnia and sleep hygiene education. For the control, they used behavioral desensitization, which Smith says was shown to be a credible placebo in a primary insomnia study. In addition to using in-home polysomnography, the researchers measured outcomes with sleep diary assessments and sensory tests of pain modulation at baseline, post-treatment, three months and six months.

Results showed that patients in the cognitive-behavioral therapy group had significantly greater reductions in wake time after sleep onset. In that group, most patients also reported significant and comparable reduction in pain over six months—with a third reporting a 30 percent reduction in pain severity. Furthermore, diary and polysomnography measurements of sleep improvement predicted decreased pain at each study end point, indicating, says Smith, that better sleep has at least some beneficial effects on pain.  

Smith considers these findings strong evidence that cognitive behavioral therapy should be used as a first-line treatment for chronic insomnia in most patients with knee osteoarthritis. “The best part,” he adds, “is that there are relatively minor side effects associated with CBT-I, unlike many sedative hypnotics, which put older adults with knee problems at risk for falls and hip fractures.”