Abstract
INTRODUCTION: Attention deficit hyperactivity disorder (ADHD) affects 2.5% of adults in the general population, compared with more than 20% among individuals treated for addictive disorders (substance use disorders (SUD) and/or behavioural addictions (BAs)). The presence of ADHD is associated with earlier onset, greater severity and poorer prognosis of addictive disorders. In this context, pharmacological treatments, including methylphenidate (MPH), are widely recommended for adults with ADHD. However, their efficacy remains moderate and may be limited by poor adherence. The association between ADHD and addictive disorders may be explained by shared endophenotypes, particularly neuropsychological patterns, which may further amplify adherence difficulties. Cognitive remediation therapy (CRT) targets impaired cognitive functions and promotes compensatory strategies, and may thereby enhance treatment adherence and overall efficacy. However, evidence in adults with ADHD, especially those with comorbid addictive disorders, remains limited and methodologically constrained. We hypothesise that combining MPH with CRT targeting shared neuropsychological deficits will be more effective for patients with ADHD and comorbid addictive disorders. Demonstrating the efficacy of this combined approach could promote the widespread use of CRT in the multimodal management of ADHD, providing patients with access to affordable and autonomous care. The objective of this study is to evaluate whether this combined approach improves functional and symptomatic outcomes in the short and medium term. METHODS AND ANALYSIS: META (MEthylphénidate dans la comorbidité TDAH - Addiction(s)) is a multicentre, randomised, single-blind controlled trial (NCT06906328). It will include 248 adults (124 per group) with ADHD requiring MPH treatment and at least one addictive disorder (SUD and/or BA). After stabilisation of MPH dosage, eligible patients will be enrolled and randomised to either (1) active CRT+MPH using PRESCO software (HappyNeuron) or (2) control CRT+MPH using AUDITICO software (HappyNeuron). CRT sessions will take place two times weekly for 12 weeks, both at the hospital and at home. Follow-up visits will occur at the end of CRT (short-term) and 6 months after the final session (medium-term). Semistructured clinical interviews on psychiatric and addictive disorders, neuropsychological assessments and self-report questionnaires of ADHD, impulsivity, self-esteem and emotion dysregulation will be administered in an unblinded manner at baseline and follow-up assessments. The primary endpoint is defined as a reduction of at least 30% in the Weiss Functional Impairment Rating Scale total score from baseline to medium-term follow-up. ETHICS AND DISSEMINATION: The study has ethical approval from the French National Ethics Committee (24 December 2024) and follows Good Clinical Practice and Standard Protocol Items: Recommendations for Interventional Trials 2025 guidelines. Participants will provide written informed consent, and data will be pseudonymised and securely archived for 15 years. Data management and monitoring will follow internal procedures, with annual quality checks. Results will be shared with patients via a simplified summary and with professionals through publications, with preprints and final papers on a French open-access repository. TRIAL REGISTRATION NUMBER: NCT06906328.