Psychopathology in adults with autism and intellectual disability.

Tsakanikos et al. (2006) compared psychiatric diagnoses in two groups of adults.

One group had autism plus intellectual disability. The other had intellectual disability alone.

They used medical records and controlled for age, sex, and ability level.

Adults with both autism and ID were no more likely to have any psychiatric diagnosis.

They were actually less likely to receive a personality disorder label.

Autism itself did not add extra psychiatric risk beyond ID.

Porter et al. (2008) found the same null result in a larger sample, reinforcing the point.

Boudreau et al. (2015) seems to disagree: average-IQ autistic adults had far more psychiatric conditions.

The difference is ID status. Elias studied people with ID; Boudreau et al. (2015) excluded them.

Hand et al. (2020) extends the story to suicidal behavior, showing ID can change risk patterns.

Stop assuming every autistic adult is mentally ill. When ID is present, base rates of depression, anxiety, or psychosis match those of other adults with ID. Screen for the same red flags you already know—sleep loss, sudden skill loss, or social withdrawal—and treat what you see, not what you expect.