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

Abstract

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.

Clinical trial registration: Registry: ClinicalTrials.gov, Identifier: NCT02001077, Title: Sleep and Pain Interventions in Fibromyalgia (SPIN), URL: https://ichgcp.net/clinical-trials-registry/NCT02001077.

Keywords: MRI; clinical trial; cognitive behavioral therapy; fibromyalgia; insomnia.

© 2018 American Academy of Sleep Medicine.

Figures

Figure 1. Study flow.

Details available from the first author upon request. CBT-I = cognitive behavioral therapy for insomnia, CBT-P = cognitive behavioral therapy for pain, WLC = waitlist control.

Figure 2. Cortical regions with significant or near-significant repeated-measures analysis of variance.

Figure 3. Effect sizes (η2p) for cortical thickness changes in each region.

Positive values indicate an increase in thickness from pretreatment to posttreatment, and negative values indicate a decrease in thickness. CBT-I = cognitive behavioral therapy for insomnia, CBT-P = cognitive behavioral therapy for pain, WLC = waitlist control.