Ropinirole Adjunct to Methylphenidate Versus Placebo Adjunct to Methylphenidate for Attention-Deficit/Hyperactivity Disorder: A Randomized, Double-Blind, Placebo-Controlled Trial Publisher Pubmed



Farahvash A ; Naseh E ; Morovvati M ; Shamabadi A ; Fard M M ; Zamani Z ; Mobini B ; Akhondzadeh S
Source: European Child and Adolescent Psychiatry Published:2026

Abstract

Current therapeutics for attention-deficit/hyperactivity disorder (ADHD) have significant limitations, necessitating innovative therapies. This study aimed to investigate the efficacy and safety of ropinirole, a dopamine agonist with anti-inflammatory and neuroprotective properties, as an add-on to methylphenidate for children with ADHD. In this eight-week, randomized, double-blind trial, 66 outpatients aged 6–17 with a diagnosis of ADHD were randomized to receive methylphenidate plus either ropinirole 0.25 mg or a matching placebo twice daily. ADHD-related symptoms were assessed using the ADHD Rating Scale-IV (ADHD-RS-IV) reported by teachers and parents at baseline and weeks 4 and 8. Inattention and hyperactivity-impulsivity subscale scores were also recorded. Additionally, adverse effects were monitored throughout the study. Data from 65 participants were used for analyses. Baseline demographic and clinical characteristics were comparable between the arms. Significant time-by-treatment interaction was observed for the ADHD-RS-IV total scores as rated by teachers (= 0.051) and parents (= 0.153). The ropinirole group demonstrated significantly greater reductions in ADHD-RS-IV total scores from baseline to the endpoint as reported by teachers (Cohen’s d = 0.530) and parents (Cohen’s d = 0.504). Also, the ropinirole group achieved higher rates of response to treatment (69.7% versus 34.4%) and robust improvement (60.6% versus 25.0%). The incidence of adverse effects was comparable. In conclusion, methylphenidate + ropinirole was safe and beneficial compared to methylphenidate + placebo for reducing inattentive, hyperactive-impulsive, and total symptoms in children with ADHD. Further studies are required. © Springer-Verlag GmbH Germany, part of Springer Nature 2026.