Autism Spectrum Disorder, Processing Speed and Stimulant Effect

Background: There is a progressive increase in prescription of stimulants for children diagnosed with Autistic Spectrum Disorder (ASD). Previous findings suggest that patients with co-occurring Attention Deficit/Hyperactivity Disorder (ADHD) and ASD might benefit from stimulants, but the knowledge is scarce and there are no clinical distinct guidelines for that matter.
Objective: The aim of this study was to analyze the effects of stimulant on cognitive attention performance in children with ASD and ADHD.
Methods: Forty children aged 6-18 years diagnosed with ASD who also met the criteria for ADHD were recruited. All children performed a computerized performance test for the assessment of cognitive attention performance three times: twice while they are drug naïve and once an hour after taking a single dose of 10 mg. methylphenidate (MPH). This performance was compared to a group of children diagnosed with "ADHD only" without ASD.
Results: A significant difference (p<0.05) was found only in the parameter of Timing - measuring cognitive processing speed. This effect is significantly different from the response of the "ADHD only" group.
Conclusion: The reaction to MPH in this group significantly improved cognitive processing speed, without changing other measured attention parameters. Improving processing speed might improve every day functioning in children with ASD who also met the criteria for ADHD in other means than expected by the medication. This unique response suggest new research targets for treatment with stimulants in ASD and ADHD children and its influence on cognitive parameters.