Clinical outcomes of a 12-week, first treatment with methylphenidate in an Italian representative sample of children and adolescents with ADHD

Current clinical guidelines suggest methylphenidate (MPH) as first-line option for treatment of attention-deficit/hyperactivity disorder (ADHD). However, the Lombardy ADHD Registry initiative has recently raised some concerns about discrepant therapeutic approaches between different clinical centers. In this naturalistic observational study, we report the experience of a third-level referral center in monitoring care services for young ADHD patients. We described the clinical characteristics of the children/adolescents who were diagnosed with ADHD from 2017 and prescribed or not with MPH. We further followed-up ADHD patients who were taking MPH for 12 weeks to assess any clinical amelioration using the Clinical Global Impression-Severity scale, controlling for other outcome predictors. One fourth of patients received a MPH prescription after the ADHD diagnosis. Those children/adolescents showed more complex clinical manifestations, with greater ADHD difficulties and neuropsychiatric comorbidities. ADHD patients displayed significant improvements of functioning after 12 weeks of the initiation of MPH use, but not after 4 weeks. IQ level and the presence of co-occurring autism predicted ADHD severity at baseline. After controlling for other predictors' effect, the severity at the first visit predicted ADHD severity after 4 weeks of MPH use, which in turn predicted the clinical functioning at the 12-week visit.