To investigate the occurrence of depression and mental health disorders other than depression among Brazilian people with intellectual disabilities, analysing data from a national household survey.

Cross-sectional epidemiological study using data from the 2019 National Health Survey (PNS).

Brazil, nationwide data collection in urban and rural private households.

272 499 individuals, among whom 1.2% (n=3198) reported intellectual disabilities.

Self-reported depression and mental health disorders other than depression (anxiety, panic, schizophrenia, bipolar disorder, psychosis or obsessive–compulsive disorder (OCD)), either isolated or comorbid.

Among people with intellectual disabilities, 43.2% reported at least one mental health disorder versus 13.7% without disabilities. In adults aged 0–59 years, intellectual disability was associated with higher odds of depression (adjusted OR (aOR) 3.25, 95% CI 1.76 to 6.00), mental health disorders other than depression (aOR 12.23, 95% CI 7.52 to 19.90) and depression associated with other mental health disorders (aOR 14.34, 95% CI 7.92 to 25.96). In older adults (≥60 years), risks also remained elevated: depression (aOR 1.71, 95% CI 1.04 to 2.79), mental health disorders other than depression (aOR 4.33, 95% CI 2.09 to 8.94) and depression associated with other mental health disorders (aOR 2.98, 95% CI 1.49 to 5.95). Women with intellectual disabilities were more likely to report depression and multimorbidity, while men more often reported non-depressive disorders. Poorer self-perceived health was consistently linked to worse outcomes across age groups.

Mental health disorders and their comorbidities are significantly more prevalent among people with intellectual disabilities in Brazil. These findings highlight the urgent need for inclusive, equitable and specialised mental healthcare policies.