Background Mental health services for patients intellectual disabilities (ID) and additional mental illnesses are only sparsely studied. Objective The objective was to describe a representative sample of patients with ID in a specialized psychiatric department. Methods Data were collected from case files in a 7-year period. Of 143 invited patients, 133 participated. Results More than 60% were admitted involuntarily. Schizophrenia was found in 30.1%, mood disorder in 25.6%, and anxiety disorders in 15.8%, Obsessive Compulsive Disorder (OCD) in 8.4% and Post Traumatic Stress Disorder (PSTD) in 12.9%, PD in 14.3%, and ADHD in 12%. Average waiting time was 6.1 months. Length of stay was 9.1 months for the inpatients. Conclusion Services for patients with ID appear to still be reliant on inpatient units for at least a proportion of their patients. More research is needed to find out why this is. The results raise questions about referring, compliance between psychiatric diagnosis, and interventions.
