Neurotrophin 3 genotype and emotional adverse effects of osmotic-release oral system methylphenidate (OROS-MPH) in children with attention-deficit/hyperactivity disorder.

Abstract

Neurotrophin 3 (NTF3) has been studied in relation to the pathophysiology of

attention-deficit/hyperactivity disorder (ADHD) and mood disorders as well as

psychostimulant action. We hypothesized that the risk of an emotional side effect

to methylphenidate (MPH) treatment may be associated with NTF3 genotypes.

Ninety-six medication-naive children with ADHD (mean age 8.70, standard deviation

1.41 years, 79 males) were genotyped and treated with MPH. At baseline, which was

prior to MPH treatment, and after two weeks of medication, investigators asked

children and their parents or caregivers about adverse events using a symptom

rating scale. ADHD subjects with the A/A genotype at the NTF3 rs6332 polymorphism

showed the highest 'Emotionality' and 'Over-focus/euphoria' factor scores,

followed by those with the G/A genotype and those with the G/G genotype (p=0.042

and p=0.045, respectively). ADHD subjects with the A/A genotype at the NTF3

rs6332 polymorphism showed the highest 'Proneness to crying' and 'Nail biting'

item scores, followed by those with the G/A genotype and those with the G/G

genotype (p=0.047 and p=0.017, respectively). These data provide preliminary

evidence that genetic variation in the NTF3 gene is related to susceptibility to

emotional side effects in response to MPH treatment in Korean children with ADHD.