BACKGROUND: National population surveys and information from the National Drug Treatment Reporting System indicate cocaine use is increasing. There is a paucity of studies focusing on comorbid cocaine and alcohol use in Ireland. AIMS: The aims of the study are to examine comorbid cocaine and alcohol use patterns in those under 45 years, presenting to a national addiction treatment unit for alcohol and drug dependence.

METHODS: A retrospective review of the substance misuse behavior of 465 individuals participating in an addiction rehabilitation programme for alcohol dependence.

RESULTS: Cocaine use among this population rose significantly between 1995 (8%) and 2006 (37.9%). There was a significant association between lifetime reported cocaine use and both psychotic disorders and deliberate self harm. Overall, the use was highest among younger age group and this declined steadily with age.

CONCLUSIONS: Cocaine use among the alcohol-dependent population is an increasing problem in the Republic of Ireland, and poses a problem of higher toxicity associated with concurrent cocaine and alcohol use.