The frequency of side effects of Ritalin was examined in a randomized double-blind placebo-controlled cross-over trial in 206 children aged 5 through 15 years with ADHD at the Marshfield Clinic and Research Foundation, Marshfield, WI. The Barkley Side Effects Questionnaire (BSEQ) was completed by parents at baseline and at the end of each of 4 treatment weeks; 0.3 mg/kg and 0.5 mg/kg per dose of Ritalin were compared to placebo in separate 2-week trials. Each treatment was given three times a day for 7 consecutive days. Five of the side effects studied, insomnia, decreased appetite, stomachache, headache, and dizziness, were significantly increased by Ritalin, even at the relatively low dose of 0.3 mg/kg; the frequency of appetite suppression was dose-related and was doubled at the higher dose. Four behaviors, daydreaming, irritability, anxiety, and nailbiting, were all significantly reduced in frequency during treatment with the higher dose of Ritalin. 
COMMENT. Patients with Tourette’s syndrome were excluded from the study. Tics were reported in baseline questionnaires by 12% of parents, but there was no reported increase in either motor or vocal tics and no tics were seen on subsequent evaluations. Parents felt less anxious about potential side effects during close monitoring. The authors advocate the use of the BSEQ in monitoring patients taking Ritalin for ADHD. Ritalin as opposed to generic methylphenidate was prescribed because a difference and less consistency in effectiveness had been noted with the generic drug.