Neurocognitive functioning in comorbid insomnia and sleep apnea patients is better after positive airway pressure therapy, but worse after cognitive behavioral therapy for insomnia: exploratory analysis of cognitive outcomes from the Multidisciplinary Approach to the Treatment of Insomnia and Comorbid Sleep Apnea study

Study Objectives Neurocognitive impairments in comorbid insomnia and sleep apnea (COMISA) are not well documented. We explored neurocognitive functioning and treatment effects in individuals with COMISA as an ancillary study to a randomized clinical trial. Methods Participants with COMISA (n = 45; 51.1% female; mean age = 52.07 ± 13.29 years), from a 3-arm randomized clinical trial combining cognitive behavioral therapy for insomnia (CBT-I) and positive airway pressure (PAP) concurrently (CBT-I+PAP) or sequentially, completed neurocognitive testing at baseline, and post-treatment. Using Bayesian linear mixed models, we estimated effects of CBT-I, PAP, or CBT-I+PAP, compared to baseline, and CBT-I+PAP compared to PAP on 12 metrics across five cognitive domains. Results This COMISA sample had worse neurocognitive performance at baseline than reported for insomnia, sleep apnea, and controls in the literature, though short-term memory and psychomotor speed performance appears intact. When comparing PAP to baseline, performance on all measures was better after treatment. Performance after CBT-I was worse compared to baseline, and only performance in attention/vigilance, executive functioning via Stroop interference and verbal memory was better with moderate–high effect sizes and moderate probability of superiority (61–83). Comparisons of CBT-I+PAP to baseline generated results similar to PAP and comparing CBT-I+PAP to PAP revealed superior performance in only attention/vigilance via psychomotor vigilance task lapses and verbal memory for PAP. Conclusions Treatment combinations involving CBT-I were associated with poorer neurocognitive performance. These potentially temporary effects may stem from sleep restriction, a component of CBT-I often accompanied by initially reduced total sleep time. Future studies should examine long-term effects of individual and combined COMISA treatment pathways to inform treatment recommendations. Clinical trial This was an ancillary study from a clinical trial (Multidisciplinary Approach to the Treatment of Insomnia and Comorbid Sleep Apnea (MATRICS), which was preregistered at www.clinicaltrials.gov (NCT01785303)).