Risperidone Versus Methylphenidate in Treatment of Preschool Children With Attention-Deficit Hyperactivity Disorder

Background: Attention Deficit Hyperactivity Disorder (ADHD) is a common psychiatric diagnosis among preschool children. Objectives: The aim of this study was to examine the Risperidone treatment compared to Methylphenidate (MPH) in preschool children with ADHD. Patients and Methods: Thirty three outpatient preschool children, aged 3-6 years, diagnosed with ADHD (The diagnosis of ADHD was established by two child and adolescent psychiatrists according to the DSM-IV-TR criteria), participated in a 6-week, double-blind clinical trial with risperidone (0.5-1.5 mg/d) and methylphenidate (5-20 mg/d), in two divided doses. Treatment outcomes were assessed using the Parent ADHD Rating Scale and Conners Rating Scale. Patients were assessed by a child psychiatrist at baseline, 2, 4 and 6 weeks after the medication started. Side effects were also rated by side effects questionnaire. Results: There were no significant differences between the two protocols on the Parent ADHD Rating Scale scores (P > 0.05) and Parent Conners Rating Scale scores (P > 0.05). Both groups showed a significant improvement in ADHD symptoms over the 6 weeks of treatment for parent ADHD Rating Scale (P < 0.001) and Parent Conners Rating Scale (P < 0.001). The most common adverse effects seen with risperidone were daytime drowsiness and anorexia (20%), and with methylphenidate it was anorexia (55%). Conclusions: Results of this study show that risperidone may be effective and well tolerated for ADHD in preschool children, but more researches are needed to clarify the potential benefits and adverse effects in long term use and comorbid conditions.