Objective: Substance misuse complicates an individual's management in adult Mental Health services. This study aimed to examine both the overall prevalence of substance misuse in those admitted to the psychiatric unit and additionally those admitted with a primary diagnosis and comorbid substance misuse. The study focuses on the associated diagnoses and demographics in 100 consecutive admissions to an acute psychiatric unit in an Irish university hospital.

Results: The combined prevalence of mental illness and substance misuse was 47%. Twenty two out of 100 (22%)were admitted primarily for the management of substance misuse and dependence (plus psychosocial reasons). Twenty-five of the patients admitted with a primary psychiatric illness (25%) were discovered to have comorbid substance misuse. At risk groups were found to be males and aged under 45 years.

Conclusion: Our study demonstrates the importance of screening and identification for substance misuse in psychiatric inpatient units; and consequently, the need for individual case management, additional development of duall diagnosis services and accurate patient data reporting to facilitate forward service-planning.