How dangerous is this really? The answer drawn from 4.2 million people born between 1958 and 1999 is that a substance use disorder raises the risk of a suicidal event sixteenfold.
Published in Molecular Psychiatry the study counted 119,220 suicidal events including attempts and deaths across the cohort. Of those people 59,436 nearly half carried a substance use disorder diagnosis.
The breakdown showed 16.2 times the risk of any suicidal event, 18.3 times the risk of an attempt and 6.3 times the risk of death compared with people who had no substance use disorder.
Even after researchers adjusted for co-occurring psychiatric illness, which accounts for much of the danger, the risk remained 6.4 times higher.
The Combination Worse Than Either Alone
Single diagnoses told only part of the story. Alcohol use disorder alone meant 9.5 times the risk, while drug use disorder alone meant 18.5 times the risk. Using both substances together produced 30.8 times the risk of any suicidal event before adjustment.
Even after researchers accounted for psychiatric comorbidity, the combination still carried 8 times the risk which marked the highest risk among all groups. The authors wrote that the AUD plus DUD combination showed the highest elevation in risk for any suicidal event.
The mixing pattern matters clinically. People who drink and also use other drugs sit in the steepest part of the risk curve.
This pattern often appears in high stress professional circles, where people may view alcohol as an acceptable form of self-medication. Family history sharpens the risk further because a close relative’s history of addiction or suicide adds to the overall burden.
Twins Siblings and Shared DNA
The study’s family design helps explain why the overlap is so strong. The researchers compared identical twins, fraternal twins, full siblings, half siblings and cousin. They found that closer genetic relationships corresponded with stronger associations between substance use and suicidal behavior.
They estimated heritability at 46 percent for substance use disorder and 41 percent for suicidal behavior and found a genetic correlation of 0.84 between the two. Shared genetic factors explained about 54 percent of the total correlation.
The authors also noted higher risk among co-twins, full siblings and half-siblings which they said supports a role for inherited liability rather than coincidence.
What Treatment Decisions Should Take From This
Integrated dual diagnosis care should become the standard rather than an upgrade. Psychiatric conditions account for much of the adjusted risk so treatment that addresses depression, anxiety or trauma alongside substance use directly addresses factors linked to the danger.
The authors identify a gap because no evidence based treatment currently targets suicidality, specifically among people with substance use disorders. That gap makes routine screening important for clinicians in settings ranging from primary care to emergency departments.
For people in treatment or considering it the practical takeaway is simpler. Be honest about combined substance use with your care team, disclose your family history and treat a program’s ability to address dual diagnosis as a safety feature rather than an amenity.
Where to Go From Here
If suicidal thinking is present now, call or text 988 in the United States immediately. For confidential guidance to treatment programs, contact SAMHSA’s National Helpline at 1-800-662-4357 or call
800-985-8516
( 
Sponsored Helpline )
. You can also search Rehab.com’s directory to find local addiction treatment centers.
