Attention Deficit Hyperactivity Disorder (ADHD) is a major comorbid psychiatric disorder in children with Autism Spectrum Disorders (ASD) that significantly undermines behavioral, social, and emotional adjustment. Although the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) does not specifically allow for a comorbid diagnosis of ADHD with ASD, many children with an ASD manifest symptoms of ADHD and are treated for it with stimulants or other medication. The few studies on ADHD in ASD have not consistently established its cognitive and behavioral manifestations, or the optimal parameters for treatment. The proposed project will address these issues through studies of cognitive and behavioral functioning in children with ASD, with and without ADHD, and through a study of medication treatment of ADHD symptoms in autism.~Participants between the ages of 7 to 12 with an autism spectrum disorder participated in the initial phase of the study to examine the nature and effects of ADHD symptoms on behavioral and cognitive functioning. Participants underwent an initial psychological testing session that included standardized measures of intellectual, adaptive behavior, language, behavioral, and emotional functioning, along with standardized diagnostic measures to confirm their diagnoses of ASD and/or ADHD (Visit 1). Children with intelligence quotients (IQs) below 50 or greater than 130 or with major sensory, motor, neurological, genetic, or psychiatric disorders that may interfere with testing were be excluded. The participants who meet eligibility criteria completed computerized tasks of attentional functioning in a second visit (Visit 2).~A subset of the children meeting criteria for the ASD/ADHD group (N=24) participated in a six-week randomized double-blind, placebo-controlled treatment trial using various doses (low, medium, or high dose) of methylphenidate (MPH). Children participated in the treatment trial will be those who qualified based on the initial phase and who do not have any physical contraindications to MPH (e.g., history of MPH intolerance). In each week of the treatment trial, the children took one of the three doses of MPH or a placebo. At the end of each week the child were evaluated in the clinic by including a medical check-up, parent interviews about the child's behavior and functioning that week, and computerized cognitive testing. Additionally, the child's parent and teacher completed questionnaires about the child's behavior each week, so that the child's home and school behaviors at each MPH dose could be assessed.
This study examined the cognitive and behavioral differences in children who have an autism spectrum disorder (ASD) with or without additional symptoms of ADHD. The study also examined the effectiveness of a range of doses of methylphenidate in improving cognitive and behavioral outcomes in children with both ASD and ADHD.