Psychiatric and Medical Conditions Among Adults with ASD

Background: Children with autism spectrum disorders (ASD) have been shown to have a higher burden of medical and psychiatric comorbidities and increased utilization of health care services compared to the general pediatric population.  However, very little is known about the general health status among the adult ASD population.  Given that increasing numbers of children are entering adulthood each year with an ASD diagnosis, an understanding of this issue is critical for resource planning and the development of effective strategies for health care delivery to adults with ASD.

Objectives: To describe the frequency of psychiatric and medical conditions among a large, diverse, insured population of adults with ASD in the US.

Methods: The study population was drawn from the adult membership (≥ 18 years) of Kaiser Permanente Northern California (KPNC) (~2.5 million) enrolled in the health plan for at least 9 months each year from 2008-2012.  Physician documented diagnoses routinely captured in KPNC electronic medical records were utilized for all analyses.  ASD cases (N=2,108) were adults with at least one ASD diagnosis (ICD-9-CM 299.0-299.8) recorded by December 2012.  A control group of adults without any ASD diagnoses (N=21,080) were sampled at a 10:1 ratio and frequency matched to cases on total length of KPNC membership, sex, and age.  We compared the prevalence of psychiatric, behavioral, and medical conditions overall and by sex, age group, and race/ethnicity between cases and controls.

Results:  Adults with ASD had significantly increased rates of depression (38% vs. 17%), anxiety (39% vs. 18%), bipolar disorder (8% vs. 1%), and suicide attempts (1.6% vs. 0.3%), and prevalence differences between cases and controls increased with age.  Among women, rates of alcohol and chemical dependency were 2-fold higher in ASD cases than controls.  Nearly all medical conditions were significantly more common in adults with ASD than controls: diabetes (6% vs. 4%), gastrointestinal disorders (47% vs. 38%), epilepsy (12% vs. 1%), sleep disorders (19% vs. 10%),  dyslipidemia (26% vs. 18%), hypertension (27% vs. 19%), and obesity (27% vs. 16%).  Among women, asthma, allergy and autoimmune disorders were present 20%-30% more often in adults with ASD than controls.  Rarer conditions, such as eating disorders, mechanical falls, vision and hearing impairments, osteoporosis, and chronic heart failure were also significantly more common among adults with ASD than controls.  Rate differences between cases and controls were variable across race/ethnic groups, especially for diabetes and epilepsy.  Of note, adults with ASD were significantly less likely to use alcohol (23% vs. 53%) or smoke (16% vs. 30%).  Finally, the rate of cancer was similar between ASD cases and controls (2.7% vs. 2.6%).     

Conclusions: Adults with ASD have a significant burden of major psychiatric and medical conditions.  Their underlying impairments in social communication and increased sensory sensitivities likely impede the delivery of preventive health care.  Improved strategies for delivering the most appropriate and effective health care are needed for this growing population.