Evidence / 2019
Prevalence of co-occurring mental health diagnoses in the autism population: a systematic review and meta-analysis
Lai MC, Kassee C, Besney R, et al. (2019). The Lancet Psychiatry.
- Population
- Autistic children and adults in studies reporting co-occurring mental health diagnoses
- Sample
- Systematic review and meta-analysis of studies reporting co-occurrence (see paper)
- Condition
- Autism; co-occurring mental health diagnoses including ADHD, anxiety, sleep, depression, OCD, bipolar, psychosis-spectrum
- Medication focus
- Not a treatment trial
- Jurisdiction
- International
- Last reviewed
- 1 September 2026
- PMID
- 31447415
- DOI
- 10.1016/S2215-0366(19)30289-5
Plain-language finding
Co-occurring mental health diagnoses are more prevalent in the autism population than in the general population. ADHD, anxiety disorders, sleep–wake disorders and depressive disorders were among the most frequently reported. Estimates varied widely between studies. Co-occurrence is common; it is not universal; and it is not a claim that autism explains every psychiatric symptom.
Important limitation
Pooled percentages are sensitive to diagnostic method, age, sample source (clinic vs community) and era. Heterogeneity was high. Clinic samples inflate co-occurrence relative to community samples.
Why we cite this
Major quantitative synthesis of co-occurring mental health diagnoses in autism, with heterogeneity kept visible.
autism · adhd · nd-overlap · psych-comorbidity · differential
Supported by clinical guidelines, regulatory information, systematic reviews, or well-established pharmacological knowledge. Still describes populations, not an individual.
Claims this source supports
ADHD and autism commonly co-occur. They were not formally allowed as co-diagnoses until DSM-5 (2013). Having one does not rule out the other, and treating one does not automatically treat the other.
Last reviewed 1 September 2026
Depression, anxiety, sleep disorders, OCD, trauma-related conditions, substance-use problems and eating disorders commonly co-occur with ADHD and/or autism. They may be separate, interacting, or both. A later developmental diagnosis does not mean the psychiatric diagnosis was imaginary.
Last reviewed 1 September 2026
Bipolar disorder, borderline personality disorder and schizophrenia-spectrum disorders can share surface features with ADHD, autism, trauma or mood presentations. They can also coexist with neurodevelopmental conditions. They are not simply manifestations of neurodivergence. Correct differentiation can materially affect treatment.
Last reviewed 1 September 2026
AuDHD is community language for autism and ADHD occurring together. It is not a separate DSM or ICD diagnosis with its own criteria. DSM-5 (2013) removed the earlier rule that had treated the two as mutually exclusive. Each condition still has to be assessed on its own terms. One does not automatically explain the other.
Last reviewed 1 September 2026