A retrospective patient record review was conducted to examine comorbid psychiatric diagnoses, and comorbid substance use, among 465 patients below 45 years of age, presenting to a national alcohol addiction treatment unit in Dublin, between 1995 and 2006. Rates were high for depressive disorder (25.3%) particularly among females (35.4%). Lifetime reported use of substances other than alcohol was 39.2%, and further analysis showed significantly higher rates of deliberate self-harm among this group. Lifetime reported use of ecstasy was also significantly associated with depression in this alcohol-dependent population using logistic regression analysis. Implications and limitations of the findings are discussed.