2026 ECNP Congress

PS02-2145

Clinical characteristics of individuals with attention-deficit/hyperactivity disorder and co-occurring substance use disorder: a systematic review and meta-analysis

Cristiana Tapoi — C.N. Schmitz, V. Oliva, M. de Prisco · Alexandru Obregia Clinical Psychiatry Hospital, Department of Psychiatry, Bucharest, Romania

2026 ECNP Congress

Introduction

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that has gained increasingly more attention in recent years in adult psychiatry, as it was proven that the symptoms beginning in childhood tend to persist in adult life in two thirds of the cases [1,2,3].

Beyond its core symptoms of distractibility, forgetfulness, difficulties organizing tasks and activities, excessive talking or fidgeting, ADHD in adults is associated with impaired decision-making, difficulty relaxing, irritability, and emotional disregulation, which leads to adult patients with ADHD being frequently misdiagnosed with mood disorders or anxiety disorders, thus delaying the initiation of a proper treatment.

Over 75% of adults with ADHD have at least one psychiatric comorbidity, with substance use disorders (SUD) affecting approximately 25% of this population [4,5]. This comorbidity carries important clinical consequences, including increased mortality, reduced treatment adherence, higher rates of hospitalization, poorer outcome, and a lower quality of life. Despite the significant comorbidity between ADHD and SUD, findings on their interplay are mixed and inconsistent, and quantitative evidence detailing the clinical characteristics of individuals with co-occurring ADHD and SUD remain limited.

Aims

This study aims to evaluate the clinical impact of a SUD diagnosis in individuals with ADHD. Specifically, it compares patients with comorbid ADHD and SUD to those with ADHD alone, examining differences in ADHD symptom severity, suicidality, additional psychiatric comorbidities, cognitive functioning, overall level of functioning, and gender distribution.

Methods

This systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search of PubMed/MEDLINE, Scopus, and PsycINFO databases was performed from inception through May 28th, 2025. Eligible studies included original research providing quantitative comparisons between individuals with both ADHD and SUD and those with ADHD alone. Random-effects meta-analyses were conducted through the R-package “metafor” using R (version 4.4.2).

Results

A total of 4,809 records were identified, of which 16 studies met the inclusion criteria and were included in the analysis. Compared to adults with ADHD alone, those with comorbid ADHD and SUD had significantly higher odds of also being diagnosed with panic disorder (OR=4.37; 95% CI: 1.11, 17.11; p=0.034), agoraphobia (OR=7.98; 95% CI: 1.33, 47.99; p=0.023), and antisocial personality disorder (OR=18.04; 95% CI: 3.55, 91.83; p<0.001).

In addition, individuals with both ADHD and SUD demonstrated lower IQ scores (OR=-0.36; 95% CI: -0.71, -0.02; p=0.038) and higher levels of impulsivity (OR=0.62; 95% CI: 0.33, 0.91; p<0.001). No significant differences were observed between the groups in terms of gender distribution, suicidality, or other psychiatric comorbidities.

Conclusions

These findings indicate that an additional diagnosis of SUD substantially complicates both the clinical presentation and the course of ADHD. Adults with co-occurring ADHD and SUD exhibit a distinct clinical profile, characterized by factors that may contribute to both the onset and persistence of substance use. The results underscore the importance of integrated, individualized clinical approaches that address the specific risks profile associated with this comorbidity.

References

  1. Thomas R, Sanders S, Doust J, Beller E, Glasziou P. Prevalence of attention-deficit/ hyperactivity disorder: A systematic review and meta-analysis. Pediatrics. 2015; 135:e994e1001
  2. Wilens TE, Spencer TJ. Understanding attention-deficit/hyperactivity disorder from childhood to adulthood. Postgrad Med. 2010; 122(5):97-109. doi: 10.3810/pgm.2010.09.2206
  3. Cherkasova M, Sulla EM, Dalena KL, Pondé MP, Hechtman L. Developmental course of attention deficit hyperactivity disorder and its predictors. J Can Acad Child Adolesc Psychiatry. 2013; 22:47e54
  4. Chen Q, Hartman CA, Haavik J, Harro J, Klungsoyr K, Hegvik TA, et al. Common psychiatric and metabolic comorbidity of adult attention-deficit/hyperactivity disorder: a population-based cross-sectional study. PLoS One. 2018; 13, e0204516
  5. Zulauf CA, Sprich SE, Safren SA, Wilens TE. The complicated relationship between attention deficit/hyperactivity disorder and substance use disorders. Curr Psychiatry Rep. 2014; 16(3):436. doi: 10.1007/s11920-013-0436