Genetics of addictions.

Addictions include a group of common, heritable psychiatric illnesses that have multiple psychiatric and medical comorbidities. Robust genetic associations have been found for alcohol dependence, nicotine dependence, and cocaine dependence. Common genetic associations have been found between alcohol dependence and aerodigestive cancers and between nicotine dependence and lung disease. These associations highlight the importance of understanding the genetics of substance dependence in the context of its multiple medical and psychiatric comorbidities.