Alcohol misuse and mental illness share genetic roots, study finds

A research team at Seoul National University Bundang Hospital (SNUBH) has identified strong genetic correlations between problematic alcohol use and a wide range of psychiatric disorders.

The study utilized a large-scale genome-wide association study (GWAS) involving more than 430,000 individuals from multiple ethnic backgrounds. The aim was to map the shared genetic architecture of alcohol misuse and mental illness more precisely than ever before.

Problematic drinking -- defined not merely by consumption volume but by patterns involving impaired control, diminished social and occupational functioning, and physical or psychological harm -- is frequently seen in psychiatric conditions such as schizophrenia and depression. Although their co-occurrence is well documented, the specific genetic variations linking them have remained poorly understood.

The team, led by Professor Myung Woo-jae of the Department of Neuropsychiatry, conducted an analysis revealing significant genetic overlaps between alcohol use problems and several psychiatric disorders.

The findings showed a genetic correlation of 73 percent with schizophrenia, 65 percent with anorexia nervosa, 60 percent with autism spectrum disorder, 50 percent with bipolar disorder, 46 percent with attention deficit hyperactivity disorder (ADHD), and 39 percent with major depressive disorder.

Professor Won Hong-hee of the Department of Digital Health at Samsung Medical Center also participated in the study. 

“These findings support the idea that problematic alcohol use and psychiatric disorders may stem from shared genetic foundations, beyond mere behavioral or environmental factors,” Professor Myung said.

Further genetic mapping pointed to two key genes, TTC12 and ANKK1, as likely contributors to both conditions. These genes play a critical role in regulating dopamine pathways involved in impulse control and the brain’s reward system. The discovery opens the door to developing new treatments that target this common biological mechanism.

“This study used cutting-edge statistical analysis and vast genomic data to uncover the genetic connections between complex conditions,” said Professor Won. “It not only advances our understanding of disease mechanisms but also supports the development of precision therapies that reflect this shared biology.”

Professor Myung also emphasized the real-world impact of the findings. “Many patients with mental illness turn to alcohol as a way of coping, but this often worsens their symptoms.”

Myung stressed that by revealing a shared genetic mechanism, the team’s research offers a new conceptual and therapeutic framework for managing dual diagnoses.

The findings were published in the American Journal of Psychiatry.