Cognitive-behavioral therapy (CBT) is linked to a significantly reduced risk of depression in patients with insomnia, new research shows.
Insomnia affects over 50% of older adults, and insomnia contributes to a twofold greater risk for major depression, investigators noted.
“We show that by treating insomnia with a simple behavioral approach called Cognitive Behavioral Therapy for Insomnia, or CBT-I, you can reduce the likelihood of developing depression by over 50%,” lead author Michael R. Irwin, MD, Cousins Distinguished Professor of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, said in an interview.
The study is unique in that the treatment “is not just reducing depression, it’s preventing depression,” Dr. Irwin added.
The findings were published online Nov. 24 in JAMA Psychiatry.
Primary outcome met
within the previous 12 months.
All were randomly assigned to receive either CBT-I or Sleep Education Therapy (SET).
CBT-I is a first-line treatment for insomnia that includes five components: cognitive therapy targeting dysfunctional thoughts about sleep, stimulus control, sleep restriction, sleep hygiene, and relaxation.
SET provides information on behavioral and environmental factors contributing to poor sleep. While sleep education provides tips on improving sleep, CBT-I helps patients implement those changes and behaviors, Dr. Irwin noted.
Both interventions were delivered by trained personnel in weekly 120-minute group sessions for 2 months, consistent with the format and duration of most CBT-I trials.
The primary outcome was time to incident or recurrent major depressive disorder as diagnosed by the Structured Clinical Interview of the DSM-5 every 6 months during 36 months of follow-up. A monthly Patient Health Questionnaire 9 (PHQ-9) was used to screen for depressive symptoms.
Results showed depression occurred in 12.2% of the CBT-I group versus 25.9% of the SET group. The hazard ratio (HR) for depression in the CBT-I group compared with the SET group was 0.51 (95% confidence interval, 0.29-0.88; P = .02). The number needed to treat to prevent incident or recurrent depression was 7.3.
After adjustment for factors affecting depression risk such as sex, educational level, income, comorbidity, and history of depression, the HR for depression in the CBT-I group versus the SET group was 0.45 (95% CI, 0.23-0.86; P = .02).
Treatment with CBT-I yielded an annual 4.1% incidence of depression, which is similar to the population rate and half the rate in SET, which was 8.6%.
‘Remission is key’
The secondary outcome was sustained remission of insomnia disorder. The investigators found a greater proportion of the CBT-I group than the SET group achieved remission after treatment (50.7% vs. 37.7%; 95% CI, 0.10-0.93; P = .02).
“Remission is really key to the benefits that we’re seeing,” said Dr. Irwin.
Inflammation may explain why insomnia raises the risk for depression, he noted. “We know sleep disturbance can lead to inflammation and we also know inflammation can produce depression,” Dr. Irwin said.
It is also possible insomnia leads to an impaired pleasure or reward system, which is linked to depression, he added.
The authors noted that because insomnia is associated with suicidal ideation and dementia, CBT-I may reduce risk for suicide or cognitive decline.
While 8-week CBT-I treatments are readily available, “unfortunately, most clinicians will prescribe medications,” said Dr. Irwin. He noted that in older adults, drugs are linked to adverse events such as falls and cognitive problems.
These new results “really argue that psychology and psychiatry need to be fully integrated into what we call collaborative care models,” Dr. Irwin said.
There were no adverse events during treatment, and none of the serious events that occurred during follow-up were attributed to the trial.