BACKGROUND: A high proportion of adults with intellectual disabilities receive psychotropic medicines, often in the absence of a mental illness but primarily off-licence for behaviours that challenge. AIM: To provide a cross-sectional view of the pattern of psychotropic medicine prescriptions with the reasons for their use among adults with intellectual disabilities in community settings in the UK. METHOD: We collected psychotropic prescription data on 112 adults with intellectual disabilities who lived in community homes or supported accommodations in the UK. This was done in the context of a feasibility RCT involving a staff training programme, SPECTROM, designed to help reduce the overmedication of adults with intellectual disabilities. RESULTS: The most commonly prescribed psychotropics were antipsychotics (47 %) followed by antidepressants (23 %), anti-epileptics (13 %) and benzodiazepines (7 %). In 45 % of cases, there was a polypharmacy of more than one psychotropic class of medicines, and in 20 %, a combination of antipsychotics and antidepressants. Antipsychotics were used for severe mental illness only in 19 % but for behaviours that challenge in 40 %, and 17 % of the time for anxiety. Antidepressants were prescribed 47.7 % of the time for depression, 11.4 % for anxiety, and 9 % for behaviours that challenge. Antiepileptics were prescribed more often for behaviours that challenge (40 %) than epilepsy (32 %). In the SPECTROM training group, the antipsychotic dose was reduced in 18.6 % of prescriptions compared with 6.5 % in the non-training group at six months follow-up. CONCLUSION: Psychotropic medicines are still prescribed in a high proportion of cases off-licence for behaviours that challenge than mental illness.