Demographic Predictors of Diagnostic Timing in Autism Spectrum Disorder and Co-occurring Mental Health Conditions:...

The present study examined the diagnostic sequencing of co-occurring autism spectrum disorder (ASD) and mental health diagnoses in youth and the impact of demographic factors on diagnostic patterns.

Data were extracted from the electronic health record of youth (n = 3357) under age 18 years in a pediatric health care system in the midwestern United States. Patients with co-occurring ASD and mental health disorders were categorized based on the order in which they were diagnosed: ASD first, mental health disorder first, or concurrent diagnoses. T -tests and linear and multinomial regressions were used to examine whether age at ASD diagnosis differed based on the presence of a mental health disorder and to examine demographic variables as predictors of diagnostic patterning.

ASD was diagnosed 3 years later in youth with a mental health disorder, t(13,464) = 34.26, p < 0.001. Youth were most often diagnosed with a mental health disorder before ASD. Girls were 0.65 times less likely than boys to receive an ASD diagnosis first compared with a mental health diagnosis first ( p = 0.006) and were diagnosed with ASD later than boys (B = 0.97, p = 0.006). Black and multiracial Hispanic children were more likely than White children to receive an ASD diagnosis first compared with a mental health diagnosis (odds ratios 1.37-1.93) and were diagnosed with ASD earlier. Minoritized children were more likely to receive externalizing diagnoses.

Findings highlight issues of diagnostic overshadowing in the diagnosis of ASD and co-occurring mental health conditions, and elucidate demographic groups who may be at risk for late diagnosis of ASD.