Using the family history method, the authors examined the relationships of parental alcoholism to alcoholism, depression, and antisocial personality disorder among 638 opioid addicts. It was concluded that, compared to addicts without parental alcoholism; addicts with parental alcoholism were more frequently concurrent alcoholics; addicts with parental alcoholism not only had alcoholism more often, but also depression and antisocial personality disorder; among alcoholic addicts, those with parental alcoholism had more severe problems with alcohol abuse; and addicts with parental alcoholism reported more disruptive childhood events. The independent additive effects of disruptive childhood events and parental alcoholism on the severity of addict disorders including alcoholism were also examined. Although alcoholic addicts had experienced more disruptive childhood events than nonalcoholic addicts, these events did not substantially contribute to increasing the severity of alcohol-related problems. Similar results were obtained for depression and antisocial behaviors in these addicts. The conclusions concerning addicts supported some of those described for "familial alcoholism" among nonaddict alcoholics, but other characteristics of alcoholics with familial alcoholism were not found among addicts.