Association between Self-Reported and Clinician-Rated Anxiety in Adults with Autism Spectrum Disorder and Adults with Schizophrenia Spectrum Disorders

Background: The prevalence of anxiety in adults with Autism Spectrum Disorder (ASD) and adults with Schizophrenia Spectrum Disorders (SSD) is high. Typically, multiple assessment modalities are used to capture specific symptomology, yet there is limited research examining self-report vs. clinician ratings of anxiety transdiagnostically in adults with ASD and with SSD.

Objectives: The current study investigated demographic factors and clinical features as predictors of clinician-assigned anxiety diagnoses transdiagnostically. It was hypothesized that self-report ratings of anxiety in both ASD and SSD diagnostic groups would be associated with increased probability of meeting diagnostic criteria for a comorbid anxiety disorder on a clinician-rated measure.

Methods: Collected as part of a larger research study, the sample included 36 adults with ASD (27 male; M=25.06 years old) and 27 adults with SSD (22 male; M=23.29 years old). Diagnoses were confirmed by the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) and Structured Clinical Interview for DSM-IV (SCID-IV). IQ was measured using the WASI-II (ASD M=105.11, SD=15.51; SSD M=95.96, SD=11.43). Anxious symptomology was measured using the self-report Beck Anxiety Inventory (BAI), and the clinician-rated Mini International Neuropsychiatric Interview (MINI). A dichotomous (yes/no) variable was created to indicate the presence (ANX)/absence (N-ANX) of an anxiety disorder based on the MINI. ASD symptomology was measured by the ADOS-2 Severity Score (DSM-5 ADOS-2 Module-4 algorithm) and SRS-2 self-report and SSD symptomology was measured by the SAPS/SANS.

Results: An independent-samples t-test was conducted to investigate differences in self-report ratings between the ANX-group and N-ANX-group. As expected, the ANX (M=13.28, SD=9.49) and the N-ANX (M=7.56, SD=9.63) groups differed significantly; t(61)=2.14, p=.04. There was a significant point bi-serial correlation between clinician and self-report ratings, r_pb(63)=-.26, p=.04, with anxiety diagnoses associated with higher ratings on the self-report. To further explore this relationship, a binomial logistic regression was performed to ascertain the effects of age, gender, IQ, level of autism and SSD symptomology, and self-report ratings on the likelihood of receiving an anxiety diagnosis on the MINI. The logistic regression model was statistically significant, χ²(7)=55.23, p<.001. The model explained 87.5% (Nagelkerke R²) of the variance in clinician ratings and correctly classified 94.8% of cases (sensitivity 94.1%, specificity 95.1%, positive predictive value 83.3%, negative predictive value 93%). Of the seven predictors, three were statistically significant: gender (B=-5.16,Waldχ² =5.14,p=.02), ADOS-2 Severity Score (B=.52,Waldχ²=6.47,p=.01), and SRS-2 Total Score (B=-.358,Waldχ² =10.31, p=.001). Males had 5.16 times lower odds of being diagnosed with anxiety than females. Increasing ADOS-2 severity scores were associated with an increased likelihood of clinician-rated diagnosis but increasing SRS-2 scores were associated with a reduced likelihood. Age and SSD symptomology approached significance (p=.06 and p=.07), respectively.

Conclusions: Results demonstrate an association between self-report and clinician ratings of anxiety, but surprisingly, self-report of anxiety was less predictive of an anxiety diagnosis than other factors such as gender or ASD symptomology. SSD symptomology was approaching significance as a predictor, which may suggest that individuals, regardless of primary diagnosis, are reporting symptomology related to both ASD and SSS that lead to a greater likelihood of a clinician-rated anxiety diagnosis.