Anxiety Disorders Affect Half of Autistic Adults in Landmark Diagnostic Interview Study

Autistic adults may be carrying a far heavier burden of anxiety than most clinics realize. A new cross-sectional study from Tehran University of Medical Sciences, published in BMC Psychiatry, found that generalized anxiety disorder was present in just over half of autistic adults attending a tertiary neurodevelopmental clinic, and social anxiety disorder in nearly as many. The researchers, led by AmirAli Soltani and colleagues, used the Structured Clinical Interview for DSM-5, the diagnostic gold standard, rather than relying on questionnaires alone, giving the findings a technical rigor that many prevalence studies lack.

The study enrolled 83 autistic adults referred to the neurodevelopmental disorders clinic of Roozbeh Hospital in Tehran. Participants had a mean age of 26.53 years with a standard deviation of 7.17, and the male-to-female ratio was 4.53 to 1, reflecting the well-documented male skew in autism referrals. Because research on adult autism in Iran is exceedingly scarce, the team set out to do two things: measure the current prevalence of comorbid anxiety disorders using a formal diagnostic interview, and examine how autism-trait measures relate to the severity of anxiety symptoms.

The diagnostic results were striking. Using the SCID-5, the current prevalence of generalized anxiety disorder was 50.6 percent, social anxiety disorder 48.2 percent, panic disorder 16.9 percent, and agoraphobia 14.5 percent. These figures sit at the high end of the international literature, and the authors argue that symptom overlap between autism and anxiety may partly explain why reported prevalence varies so widely between studies. When autistic traits and anxiety symptoms blur into one another, diagnosis becomes complicated and access to proper treatments can be delayed or denied.

What makes the study technically interesting is how it handled the measurement problem. Rather than depending on a single instrument, the researchers triangulated data from participants’ prior clinical records, including the Autism-Spectrum Quotient, the Ritvo Autism Asperger Diagnostic Scale-Revised, and measured intelligence quotient, alongside the Hamilton Anxiety Rating Scale and the SCID-5 interview. The Hamilton scale is a clinician-rated measure of anxiety severity, which means the anxiety findings were not simply self-reported but anchored to structured clinical judgment.

The correlation analysis revealed a clear pattern. Hamilton anxiety scores correlated positively with both RAADS-R scores, with a correlation coefficient of 0.49 and a 95 percent confidence interval spanning 0.282 to 0.654 at a p value below 0.001, and with AQ scores, where the coefficient was 0.33 with a confidence interval of 0.096 to 0.532 at a p value of 0.005. In plain terms, the more pronounced a participant’s autistic traits, the more severe their rated anxiety symptoms tended to be.

Crucially, the association survived statistical adjustment. After controlling for age, sex, and IQ, RAADS-R remained positively associated with Hamilton anxiety scores, with an unstandardized coefficient of 0.154, a standardized beta of 0.419, and a confidence interval of 0.071 to 0.237 at p below 0.001. The AQ association also held, with a coefficient of 0.619, a beta of 0.345, and a confidence interval of 0.193 to 1.045 at p equal to 0.005. This suggests the link between autistic traits and anxiety severity is not an artifact of demographic differences within the sample.

The group comparisons added further texture. Participants with generalized anxiety disorder had significantly higher RAADS-R scores than those without it, with a Cohen’s d of 0.765 and a p value of 0.002, indicating a moderate-to-large effect. The social anxiety contrast was even sharper: those with social anxiety disorder had higher RAADS-R scores with a Cohen’s d of 1.111 at p below 0.001, a very large effect, and higher AQ scores with a Cohen’s d of 0.593 at p equal to 0.017. Social anxiety, in particular, appears tightly bound to the intensity of autistic traits in this clinical population.

The authors interpret these findings as evidence of a positive association between autism-trait measures and the severity of anxiety disorders as reflected by Hamilton scores, combined with a very high prevalence of diagnosable anxiety conditions in this tertiary clinic sample. They emphasize that anxiety disorders are known to adversely affect quality of life in autistic individuals, and that the estimated adult autism prevalence, roughly 11 per 1000 individuals, means the scale of the problem is substantial even before considering how many autistic adults remain undiagnosed until adulthood.

The study carries practical weight for clinical systems. The authors call for improved recognition and management of anxiety in autistic adults, the development of targeted support programs, and enhanced training of mental health professionals in adult autism. In Iran, where adult autism research is exceedingly scarce, the findings offer some of the first systematically collected prevalence data, drawn from a clinic that serves as a referral hub for the capital. The male-to-female ratio also highlights how adult autism services may be under-identifying autistic women, a concern echoed across the international literature.

There are limits worth noting. The sample of 83 participants came from a single tertiary clinic, so the prevalence figures describe a referred clinical population rather than the general community, and the cross-sectional design cannot establish whether autistic traits cause anxiety or whether the two conditions share underlying mechanisms. The authors also note that the published version is an early shared article subject to further edits. Even so, the combination of a structured diagnostic interview, clinician-rated anxiety severity, and adjusted statistical models makes this one of the more methodologically careful studies of comorbid anxiety in autistic adults, and a signal that autism services worldwide need to treat anxiety not as a side issue but as a core clinical concern.

Subject of Research: Psychiatry

Article Title: Investigating the prevalence of anxiety disorders in autistic adults referred to the neurodevelopmental disorders clinic of Roozbeh hospital using the Structured clinical interview for DSM-5®

Article References: Soltani, A., Kalantari, A., Alaghband-rad, J., & Motamed, M. (2026). Investigating the prevalence of anxiety disorders in autistic adults referred to the neurodevelopmental disorders clinic of Roozbeh hospital using the Structured clinical interview for DSM-5®. BMC Psychiatry. https://doi.org/10.1186/s12888-026-08568-y

Image Credits: AI Generated

DOI: 10.1186/s12888-026-08568-y

Keywords: autism spectrum disorder, anxiety disorders, adults, SCID-5, Hamilton anxiety scale, BMC Psychiatry, Investigating, prevalence, anxiety, disorders, autistic, referred