Variables at the Time of ASD Diagnosis in Toddler Years Predict Outcome in Adaptive Functioning and ADHD Co-Morbidity in Adolescence: a Long-Term Follow-up Study

Rational

Short-term follow-up studies in ASD reported that cognitive ability, autism severity, adaptive functioning and age at diagnosis predicted outcome. Adolescents with ASD have shown high rates of attention deficit/hyperactivity disorder (ADHD).

Objectives:

To examine how measures of age, cognitive ability, autism severity and adaptive skills at diagnosis can predict long-term outcomes in adaptive skills and ADHD symptoms.

Methods:

The study included 61 participants, (Males=55, Females=6) with an age range of 10:5– 7:10y (M=13:6±1:10y). Participants were diagnosed with ASD at 1:3-3:1y (M=2:2±0:5y) (T1) using standardized tests and were reassessed (T2) after 8:7-15:7y. Outcome measures included, Vineland adaptive behavior scales (VABS)] composite score; autism severity [the Autism Diagnosis Observation Schedule (ADOS), calibrated severity scale (CSS), ADOS social-affect CSS (SA-CSS) and restrictive and repetitive behaviors CSS (RRB-CSS) (≥4-ASD)] at T1 and T2; Inattention and Hyperactivity/Impulsivity scores from the Conners` Rating Scales–Revised (CRS-R) (score>60 - significant) at T2. Independent variables included, T1 DQ, VABS score, ADOS-SA-CSS, ADOS-RRB-CSS scores and age of diagnosis.

Results:

When VABS score served as the dependent variable (DV), ADOS-SA-SCC score (p<.01) and age of diagnosis (p<.05) correlated negatively and significantly with VABS score.

When Hyperactivity/Impulsivity score served as the DV, T1-DQ score (p<.05) correlated significantly and positively and T1-VABS score (p<.05) correlated significantly and negatively with Hyperactivity/Impulsivity score.

When Inattention score served as the dependent variable, T1DQ score (p<.05) and T1ADOS-RRB-CSS (p<.05) correlated significantly and positively with inattention score.

Conclusions

Autism severity and level of functioning during early diagnosis of ASD predicted outcome in adaptive skills and ADHD co-morbidity.