Abstract
BACKGROUND: Adults with attention-deficit/hyperactivity disorder (ADHD) often have comorbid substance use disorders (SUDs). In Italy, individuals with both ADHD and heroin use disorder (HUD) are usually treated in addiction services with opioid agonist therapy (OAT), but stimulant medications are rarely prescribed. This may create a treatment gap for core ADHD symptoms. AIM: This study examined the clinical and behavioural profiles of ADHD patients with HUD who receive OAT but no stimulant treatment, compared to ADHD patients without opioid use disorder (ADHD/NoHUD) on standard pharmacotherapy. All participants were considered treatment responders in their respective services. METHODS: Data were collected from two outpatient clinics and included 103 adult ADHD patients assessed using validated tools for symptom severity, emotional dysregulation, and global functioning. Differences between groups were analysed using univariate tests and logistic regression. RESULTS: The ADHD+HUD group was significantly older and showed higher levels of emotional dysregulation, impulsivity, and current cocaine use. Despite clinical stability, these individuals presented a more severe psychopathological profile than their ADHD/NoHUD counterparts, who received stimulant-based treatment. CONCLUSIONS: Although limited by its cross-sectional nature and setting-related confounders, the study indicates that OAT alone may not be sufficient to manage neurodevelopmental symptoms in ADHD+HUD patients. Further research is necessary to assess the safety and efficacy of integrated stimulant-based treatments, ideally within dual disorder services combining psychiatric and addiction expertise.