Psychiatric comorbidities in alcohol use disorder.

Alcohol use disorder is a major contributor to the morbidity and mortality burden worldwide. It often coexists with other psychiatric disorders; however, the nature of this comorbidity is still a matter of debate. In this Series paper, we examine the main psychiatric disorders associated with alcohol use disorder, including the prevalence of co-occurring disorders, the temporal nature of the relationship, and mechanisms that might explain comorbidity across the lifespan. Overall, this disorder co-occurs with a wide range of other psychiatric disorders, especially those disorders involving substance use and violent or aggressive behaviour. The causal pathways between alcohol use disorder and other psychiatric disorders are heterogeneous. Hypotheses explaining these relationships include reciprocal direct causal associations, shared genetic and environmental causes, and shared psychopathological characteristics of broader diagnostic entities (eg, externalising disorders). Efforts to untangle the associations between alcohol use disorder and other disorders across the lifespan remain a crucial avenue of research.