Insomnia and depression have long been closely linked and when individuals suffer from both conditions, practitioners tend to focus on treating the depression — yet Swedish researchers have argued that failing to treat insomnia in individuals with depression can hinder recovery and increase relapse risk.
Researchers conducted a randomized controlled trial with a three-year follow-up to compare cognitive behavioral therapy for insomnia (CBT-I) with cognitive behavioral therapy for depression (CBT-D) for patients with insomnia and depression to determine which option may be most beneficial.
The study, published in the journal Sleep in 2017, involved 43 adults with an average age of 47 years. Sixty-three percent of participants were taking sleeping pills, and just under one-third were taking antidepressants. All participants had been diagnosed with major depression and insomnia by psychiatrists.
Participants were randomly assigned to a group that received nine weeks of therapist-guided online CBT-I or a group that received nine weeks of therapist-guided online CBT-D.
The short term effects of CBT for insomnia and depression
After nine weeks, both groups showed statistically significant improvements on both insomnia severity and severity of depressive episodes as measured by the Insomnia Severity Index (ISI) and Montgomery–Åsberg Depression Rating Scale (MADRS), respectively. However, analysis of the data found CBT-I had the biggest effect on both insomnia and depression.
At the end of the nine weeks, researchers found that just 35 percent of those in the CBT-I group still suffered from major depression and just 33 percent had insomnia.
For those in the CBT-D group, 57 percent were still found to suffer from major depression and 43 percent still had insomnia.
The long term effects of CBT for insomnia and depression
After three years, improvements in both symptoms were maintained regardless of the treatment group. Fifty-six percent of interviewed participants no longer had a diagnosis of depression, while 62 percent no longer had a diagnosis of insomnia.
With that being said, CBT-I was still found to be superior to CBT-D for insomnia symptoms, although there were no significant differences between treatment groups in terms of depression.
So is CBT-I more effective than CBT-D?
Although both treatment options led to improvements in insomnia and depressive symptoms, CBT-I was found to be the superior treatment even three years after treatment.
The authors of the study suggested this may be partly due to the fact that participants in the CBT-I group were more positive about the treatment compared to those in the CBT-D group. Furthermore, those in the CBT-D group tended to have more severe symptoms and additional comorbidities that may have hindered the effect of the CBT-D treatment — and researchers pointed out that CBT-I (although found to be the superior treatment option) would likely not be a sufficient treatment for a majority of these individuals.
Finally, it’s worth being reminded that the sample size in this study was small — there were only 43 participants and only 37 responded to the follow-up three years after treatment.
That being said, this study does highlight the importance of treating insomnia when comorbid with depression since it can reduce insomnia severity, aid recovery from depression, and may even prevent a relapse into depression.
These findings led the authors of the study to suggest that individuals with both insomnia and depression should be offered CBT-I in addition to medication or psychological treatment for depression.