Objective: Attention-deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder in school-age children. It is accepted that sensory-motor and attention functions are closely associated and up to two thirds of children with ADHD suffer motor skill problems that adversely affect their social adaptation, peer relations, and academic skills. Atomoxetine (ATX) and methylphenidate (MPH) are preferentially used drugs for treatment. MPH is a central nervous system stimulant, whereas ATX is a non-stimulant selective norepinephrine reuptake inhibitor that is used to treat ADHD. The impact of ATX and MPH on attention and ADHD symptoms is well documented. However, the effects of MPH on motor skills are less studied and no data are currently available on the effects of atomoxetine on motor skills. The aim of this study is to investigate the effects of MPH and ATX on gross and fine motor skills in school-aged children with ADHD.
Methods: Participants were 36 right-handed boys with ADHD (aged between 6 and 10 years, mean 7.88 years). The Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version was used to confirm the diagnosis and rule out other comorbid psychiatric disorders. Gross and fine motor skills were assessed with the Bruininks–Oseretsky Test of Motor Proficiency, Second Edition (BOT-2). Twenty-five boys were treated with ATX and 11 with methylphenidate. BOT-2 was applied to both groups before and after 8–12 weeks of treatment.
Results: There were no statistically significant differences between the ATX and the MPH groups for all subtests of BOT-2 pre- and post-medication. When both groups were compared in terms of preand post-treatment gross and fine motor skills, the scores for fine manual control of 12 (48%) children in ATX group increased but did not reach statistical significance. The scores for fine manual control of 5 (45%) children in MPH group increased but did not reach statistical significance. Surprisingly, statistically significant decrease was found in running speed and agility, strength, and body coordination scores in the ATX group, and statistically significant decrease was found in body coordination score in the MPH group.
Conclusion: Motor coordination is important in daily life and poor motor skills have a negative impact on a child’s daily living and academic performance. Furthermore, this problem may persist into adulthood with an increase in problems associated with psychosocial adjustment. Our preliminary results revealed that although there was an increase of fine motor control scores after treatment in both groups, statistically significant difference was not found between before and after treatment. Significant decrease in speed and agility and strength scores may be due to reduced impulsivity. While few studies have revealed an improvement on standardized evaluation of attention and motor skills in children taking MPH, more research is needed to gain an understanding of the relationship between motor skills deficits, attention, inhibition, and the effects of ADHD medications.