New-onset psychiatric disorders in individuals with autism.

Roberts et al. (2008) followed autistic adults who had been diagnosed as children. They wanted to know how many would develop brand-new psychiatric disorders later in life.

The team checked medical records and gave fresh interviews to see who met criteria for a new illness.

One in every six adults had a definite new psychiatric disorder appear after childhood. Obsessive-compulsive disorder, catatonia, and mood disorders with obsessive features topped the list.

The risk stayed the same for both men and women.

Hilton et al. (2010) extends this picture. They looked at autistic adults who also had intellectual disability and found over half had a psychiatric disorder. The higher rate makes sense because the 2008 study only counted new illnesses that showed up after childhood, while the 2010 study counted any current disorder.

Orinstein et al. (2015) seems to disagree at first glance. They reported lower psychiatric rates in youth who no longer met autism criteria. The key difference is population: the 2015 paper studied kids who "lost" their diagnosis, while Jane et al. studied adults who kept it. Fewer autism traits means fewer comorbidities, so the numbers line up once you account for that.

Adamou et al. (2025) acts as a modern successor. They sampled adults currently referred for autism assessment and again found anxiety and OCD as the most common co-occurring conditions, confirming the 2008 pattern still holds today.

If you work with autistic teens or adults, plan to screen for OCD, mood, and catatonic symptoms at every visit. A clear childhood diagnosis does not protect against new illness. Flag sudden changes in rigidity, movement, or mood and refer for psychiatric evaluation early.