Contributing factors to advanced brain aging in depression and anxiety disorders

Abstract

Depression and anxiety are common and often comorbid mental health disorders that represent risk factors for aging-related conditions. Brain aging has shown to be more advanced in patients with major depressive disorder (MDD). Here, we extend prior work by investigating multivariate brain aging in patients with MDD, anxiety disorders, or both, and examine which factors contribute to older-appearing brains. Adults aged 18-57 years from the Netherlands Study of Depression and Anxiety underwent structural MRI. A pretrained brain-age prediction model based on >2000 samples from the ENIGMA consortium was applied to obtain brain-predicted age differences (brain PAD, predicted brain age minus chronological age) in 65 controls and 220 patients with current MDD and/or anxiety. Brain-PAD estimates were associated with clinical, somatic, lifestyle, and biological factors. After correcting for antidepressant use, brain PAD was significantly higher in MDD (+2.78 years, Cohen's d = 0.25, 95% CI -0.10-0.60) and anxiety patients (+2.91 years, Cohen's d = 0.27, 95% CI -0.08-0.61), compared with controls. There were no significant associations with lifestyle or biological stress systems. A multivariable model indicated unique contributions of higher severity of somatic depression symptoms (b = 4.21 years per unit increase on average sum score) and antidepressant use (-2.53 years) to brain PAD. Advanced brain aging in patients with MDD and anxiety was most strongly associated with somatic depressive symptomatology. We also present clinically relevant evidence for a potential neuroprotective antidepressant effect on the brain-PAD metric that requires follow-up in future research.

Fig. 1. Brain-age prediction.

A Correlation between predicted brain age and chronological age in controls (r = 0.73, R² = 0.45, p < 0.0001) and patients (r = 0.72, R² = 0.36, p < 0.0001). Of note, predicted brain age reflects estimates corrected for the offset (brain age_corrected = brain age − brain PAD − mean brain-PAD_controls). B There was a residual effect of age on the brain-PAD outcome in controls (r = −0.32, p = 0.01) and patients (r = −0.37, p < 0.0001), C which was statistically corrected for by adding age as a covariate in all models.

Fig. 2. Brain-PAD differences and clinical characteristics.

A AD-free patients showed significantly higher brain PAD compared with AD-using patients (+2.58 years [SE 1.02 years], Cohen’s d = 0.36, 95% CI 0.09–0.64) and controls (+2.63 years [SE 1.10 years], Cohen’s d = 0.31, 95% CI 0.01–0.60). B Advanced brain aging was associated with overall higher total depressive symptoms (b = 0.07 years per unit increase on the Inventory of Depressive Symptoms, p = 0.03), C total anxiety symptoms (b = 0.11 years per unit increase on the Beck’s Anxiety Inventory, p = 0.01), but not specifically with D the mood/cognition (b = 0.89 years per unit increase on average sum score, p = 0.27) or E immunometabolic (b = 0.45 years per unit increase on the average sum score, p = 0.62) symptom cluster. The association in (B) seemed to be driven mostly by F a specific cluster of somatic symptoms (b = 4.03 years per unit increase on the average sum score, p < 0.0001). Brain-PAD estimates (in years) were residualized for age, sex, education level (years) and two dummy variables for scan location.