Behaviors related to self-regulation, such as substance use disorders or antisocial behaviors, have far-reaching consequences for affected individuals, their families, communities, and society at large1,2. Collectively, this group of correlated traits are classified as externalizing3. Twin studies have demonstrated that externalizing liability is highly heritable (~80%)4,5. To date, however, no large-scale molecular genetic studies have utilized the extensive degree of genetic overlap among externalizing traits to aid gene discovery, as most studies have focused on individual disorders6. For many high-cost, high-risk behaviors with an externalizing component – opioid use disorder and suicide attempts7 being salient examples – there are limited genotyped cases available for gene discovery8,9.
