Very Different Psychiatric Diagnoses Share Common Genes

"By integrating genome-wide data from a million+ people with 14 psychiatric disorders, a 2026 Nature study marked a turning point in psychiatric science, showing many common psychiatric diagnoses are not genetically separate diseases. Instead, they share genetic liability (five genomic factors) across major psychiatric diagnoses, shaped by neurodevelopmental biology and life experiences. These findings challenge the disease model in psychiatric diagnoses and the Diagnostic and Statistical Manual of Mental Disorders (DSM)."

"Psychiatric manual categories still help with communication and treatment planning, but are imperfect proxies for personalized medicine or treatment predictions. The study confirmed what some clinicians already knew- how patients respond to treatment matters more than the disorder's name. Also, comorbidity is common, and patients often move between diagnoses in the same cluster. Depression, anxiety, and posttraumatic stress disorder ( PTSD) often present together because of overlapping tendencies like negative emotions and stress sensitivity."

Genome-wide data from over one million people across 14 psychiatric disorders indicate that many common psychiatric diagnoses share genetic liability organized into five genomic factors. Alcohol, cannabis, opioid, and nicotine use disorders share substantial genetic liability and cluster together as a single brain disorder. Genetic overlap links depression, anxiety, and PTSD through shared neurodevelopmental risks and stress sensitivity, producing high comorbidity and diagnostic shifts over time. Psychiatric manual categories aid communication and treatment planning but are imperfect proxies for personalized medicine or treatment prediction. Treatment response often matters more than diagnostic labels for clinical outcomes.

Read at Psychology Today