2026 ECNP Congress

EP01-1006

Attention deficit hyperactivity disorder and alcohol use disorder: from neurodevelopmental risk to clinical comorbidity

Duarte Cotovio — R.M. Lousada, R. Soares Nogueira, D. Rodrigues, M.L. Figueiredo, M. Mestre, M.J. Heitor · Hospital Loures - ULS Loures-Odivelas, Department of Psychiatry and Mental Health, Lisboa, Portugal

2026 ECNP Congress

Introduction

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition characterised by inattention, hyperactivity, and impulsivity, with a worldwide prevalence of approximately 5% in children and 2.5–3% in adults.[1] Alcohol use disorder (AUD) represents one of the most prevalent and burdensome psychiatric comorbidities associated with ADHD across the lifespan.[2,3,4] Despite growing evidence of their bidirectional relationship, the neurobiological mechanisms underpinning this comorbidity remain incompletely understood, and integrated clinical approaches are lacking.[1] This narrative review aims to synthesise current evidence on the epidemiology, shared neurobiological substrates, diagnostic challenges, and therapeutic implications of ADHD and AUD comorbidity.

Methods

A narrative review of the literature was conducted through systematic searches in PubMed, MEDLINE, PsycINFO, and EMBASE. Search terms included “ADHD”, “attention deficit hyperactivity disorder”, “alcohol use disorder”, “alcoholism”, “substance use disorder”, “comorbidity”, “neurobiology”, and “treatment”. Priority was given to meta-analyses, systematic reviews, longitudinal cohort studies, and randomised controlled trials published between 2000 and 2024.

Results

Epidemiological evidence consistently demonstrates a robust bidirectional association between ADHD and AUD. Approximately 23% (95% CI: 19.4–27.2%) of patients in addiction treatment settings meet DSM criteria for comorbid ADHD,[2] while prospective longitudinal studies show that childhood ADHD confers a significantly elevated risk of developing AUD in adulthood (OR 1.35–1.74).[3,4] This risk appears further amplified in the presence of additional psychiatric comorbidities, such as bipolar disorder, where comorbid ADHD more than doubles the likelihood of AUD (OR 2.50; 95% CI: 1.91–3.27).[5] Shared neurobiological mechanisms appear central to this relationship: dysregulation of the mesolimbic dopaminergic system, compromised prefrontal executive control, and heightened behavioural impulsivity converge across both disorders.[1,3] The self-medication hypothesis — whereby sedating properties of alcohol temporarily alleviate hyperactivity and emotional dysregulation — may partially account for the elevated prevalence of AUD in ADHD populations.[1] From a developmental perspective, early-onset ADHD accelerates substance use initiation, with adverse neuroplastic consequences on prefrontal cortex maturation that may perpetuate executive dysfunction.[1,3] Diagnostically, the substantial symptom overlap between ADHD, alcohol intoxication, and withdrawal —including inattention, impulsivity, and affective lability — creates significant challenges, necessitating ADHD assessment after an adequate period of abstinence.[1] Pharmacologically, standard ADHD medications, including methylphenidate and atomoxetine, demonstrate reduced efficacy in the presence of active AUD; co-ingestion appears associated with only minimal acute toxicity at therapeutic doses, though enhanced alcohol consumption and chronic harm remain concerns.[1] Combined pharmacological and psychotherapeutic approaches, particularly integrated cognitive-behavioural therapy, represent the most promising therapeutic framework, though high-quality evidence in this specific population remains limited.[1]

Discussion / Conclusions

ADHD and AUD constitute a clinically significant and neurobiologically coherent comorbidity, driven by shared dopaminergic dysfunction, impulsivity, and executive deficits.[1,2,3] Systematic screening for ADHD in AUD populations, and vice versa, is essential in clinical practice. Future research should prioritise longitudinal studies clarifying causal pathways, and randomised controlled trials evaluating integrated treatment approaches in this underserved population.[1,4]

References

1.Dirks H, Scherbaum N, Kis B, Mette C. ADHD in adults and comorbid substance use disorder: prevalence, clinical diagnostics and integrated therapy. Fortschr Neurol Psychiatr. 2017;85:336–344. 2.van Emmerik-van Oortmerssen K, van de Glind G, van den Brink W, Smit F, Crunelle CL, Swets M, et al. Prevalence of attention-deficit hyperactivity disorder in substance use disorder patients: a meta-analysis and meta-regression analysis. Drug Alcohol Depend. 2012;122(1–2):11–19. 3.Lee SS, Humphreys KL, Flory K, Liu R, Glass K. Prospective association of childhood attention-deficit/hyperactivity disorder (ADHD) and substance use and abuse/dependence: a meta-analytic review. Clin Psychol Rev. 2011;31(3):328–341. 4.Charach, A., Yeung, E., Climans, T., Lillie, E. Childhood attention-deficit/hyperactivity disorder and future substance use disorders: comparative meta-analyses. Journal of the American Academy of Child and Adolescent Psychiatry. 2011; 50(1), 9–21. 5.Bartoli F, Callovini T, Calabrese A, Cioni RM, Riboldi I, Crocamo C, et al. Disentangling the association between ADHD and alcohol use disorder in individuals suffering from bipolar disorder: a systematic review and meta-analysis. Brain Sci. 2022;12:38.