Implications of comorbid ADHD in ASD interventions and outcome: Results from a naturalistic follow up study from south India

Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder commonly associated with Attention Deficit Hyperactivity Disorder (ADHD), the prevalence ranging from 14-70%. The current study attempted to assess the impact of comorbid ADHD in children with ASD, in terms of challenges in diagnosis, treatment, intervention outcomes and parental stress and coping through a naturalistic design. Methods: Fifty children aged 2-6 years with ASD were recruited, assessed and followed up for six months. Twenty children were found to have comorbid ADHD. Severity of ASD and ADHD was assessed by Childhood Autism rating scale and Connor's abbreviated rating scale respectively. Parental stress and coping was assessed by Family Interview for stress and coping. Results: The diagnosis of ASD was apparently obscured by ADHD symptoms in about 22% of cases, as only diagnosis of ADHD was made at the time of referral to our centre. ADHD was the most common comorbidity followed by intellectual disability and seizure disorder. About 66% of children received combination of pharmacological and behavioral interventions. Clonidine was the most common medication to be used and was well tolerated. The improvement in ADHD symptomatology showed positive correlation with improvement with ASD-specific interventions as reflected by change in severity scores. Severity of ADHD significantly also predicted parental stress and coping, and thereby engagement in ASD-specific interventions. Conclusion: The current study highlights the need for screening and early diagnosis of comorbid ADHD in children with ASD and vice versa considering the management challenges. In case of multiple comorbid neurodevelopmental disorders, early interventions for one disorder can improve the outcome of the other.