Background: Psychotropic medication is frequently administered to people with intellectual disability with mental health and/or behavioural problems, instead of other non-pharmacological interventions. This study describes the mental health and behavioural problems of people aging with intellectual disability, their psychotropic medication intake, and the factors contributing to a greater medication intake. Method: The sample consisted of 991 people with intellectual disability over 45 years. Descriptive statistics and multinominal logistic regression were carried out. Results: Antipsychotics were the most used psychotropic drug. Older people with mild intellectual disability living in institutions and affected by mental health and behavioural problems were more likely to take larger amounts of psychotropic medication. Conclusions: Antipsychotics continue to be widely used by people with intellectual disability and mental and behavioural health problems, especially those in institutionalised settings. Future research should consider if medication intake could be reduced providing better supports in the community and non-pharmacological interventions.