Gray Matter Changes Following Cognitive Behavioral Therapy for Patients With Comorbid Fibromyalgia and Insomnia: A Pilot Study

Study Objectives: Insomnia frequently co-occurs with fibromyalgia, which is associated with gray matter atrophy. We examined the effect of cognitive behavioral therapy for insomnia (CBT-I) and pain (CBT-P) on cortical thickness. Methods: Patients with fibromyalgia and insomnia underwent MRI before and after random assignment to CBT-I (n = 14), CBT-P (n = 16), or waitlist control (WLC; n = 7). Results: Repeated-measures analyses of variance revealed significant interactions for two regions (left lateral orbitofrontal cortex, left rostral middle frontal, Ps < .05) and trends for four regions (right medial orbitofrontal cortex, right posterior cingulate, left caudal middle frontal, left transverse temporal; Ps < .10). Cortical thickness increased in all regions for CBT-I and decreased in five regions for CBT-P and WLC. Hierarchical regressions revealed that for the CBT-I group, reductions in wake after sleep onset were associated with an increase in cortical thickness. Conclusions: Our pilot study presents novel evidence suggesting that CBT-I may slow or reverse cortical gray matter atrophy in patients with fibromyalgia and insomnia.