Insomnia does not appear to be associated with substantial structural brain changes.

STUDY OBJECTIVES: Sleep has been demonstrated to significantly modulate brain plasticity and the manifestation of mental disorders. However, previous studies on the effect of disrupted sleep on brain structure have reported inconsistent results. The goal of the current study was to investigate brain morphometry in a well-characterized large sample of patients with primary insomnia (PI) in comparison with good sleeper controls. DESIGN: Automated parcellation and pattern recognition approaches were supplemented by voxelwise analyses of gray and white matter volumes to analyze magnetic resonance images. All analyses included age, sex, and total intracranial volume as covariates. SETTING: Department of Psychiatry and Psychotherapy of the University of Freiburg Medical Center. PARTICIPANTS: There were 28 patients with PI (10 males; 18 females; age 43.7 ± 14.2 y) and 38 healthy, good sleepers (17 males; 21 females; age 39.6 ± 8.9 y). INTERVENTIONS: N/A. RESULTS: No significant between-group differences were observed in any of the investigated brain morphometry variables. CONCLUSIONS: Altered brain function in insomnia does not appear to have a substantial effect on brain morphometry on a macroscopic level.