Biological and neurocognitive correlates of comorbid post-traumatic stress disorder and alcohol use disorder: a systematic review.

TL;DR

This systematic review of 14 studies found suggestive evidence of distinct neurobiological alterations (lower neurometabolites, white matter integrity, and hippocampal volume) and genetic vulnerabilities in comorbid PTSD and alcohol use disorder, but notes insufficient data and significant methodological limitations warrant caution in interpretation.

Key findings

• Genetic studies showed 72% overlap between PTSD and AUD in female twins, with DRD2 A1 allele and absence of APOE ϵ2 allele associated with PTSD and drinking
• Neuroimaging findings included lower neurometabolites, reduced white matter integrity, and smaller hippocampal volume in comorbid PTSD & AUD
• Studies examining cortisol and ACTH found no unique markers distinguishing comorbid PTSD & AUD from single disorders
• Major limitations included selection bias (predominantly male veterans) and inadequate sample size justification across included studies

Why this matters at the bedside

Understanding biological pathways linking PTSD and AUD comorbidity could inform treatment strategies, but the current evidence base is too limited to guide clinical practice decisions.