Title : The relationship between ADHD and addictive behaviours: Implications for economic and health outcomes

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent neurodevelopmental disorder that often continues into adulthood, resulting in corresponding adverse social, occupational, and economic costs. Addictive behaviours, substance use disorders (SUDs), or behavioural addictions are some of the most serious comorbidities with ADHD. This narrative review explores how ADHD is interconnected with addictive behaviours, focusing on prevalence, underlying psychological/neurobiological factors, and overall implications with regard to healthcare and economic productivity. Data from available scientific evidence suggests that this phenomenon is grounded in a bidirectional relationship wherein core symptoms of ADHD, especially impulsivity and regulatory dysfunction, create higher vulnerability to addictive behaviours, but concurrent addictive behaviour exacerbates functional deficits in ADHD.

Keywords: Attention-deficit/hyperactivity disorder; Addictive behaviours; substance use disorder; Behavioural addiction; Impulsivity; Economic burden Introduction 
Attention Deficit/Hyperactivity Disorder (ADHD), traditionally seen as a childhood disorder, often persists into adulthood and is associated with functional impairment and increased risk of psychiatric illnesses, such as substance use disorder. Given these significant consequences, a comprehensive understanding of the link between ADHD and addiction is essential.

Literature Review There is substantial evidence that links ADHD not only to substance addictions but to behavioural addictions as well. Population-based studies have found high levels of alcohol use disorder, nicotine use disorder, stimulant use disorder, and opioid use disorder in people suffering from ADHD. Additionally, other forms of behavioural addictions like internet addiction problems, gaming disorder problems, and compulsive buying problems occur at high rates in these individuals.

Some research has found common risk factors between ADHD and addictive behaviours that include impulsivity, emotional regulation, and executive functioning deficits. More emphasis has been placed on the neurobiological model that sees the dysfunction of reward pathways and dopamine as the underlying cause that results in reward hypersensitivity and the inability to suppress impulses in ADHD, as well as addictive behaviour. Of course, the process between the symptoms of ADHD and the beginnings of substance use has also been seen to be bidirectional, with the persistent use of substances affecting the attentional deficits as well as the control of impulses that are present in ADHD.

Table 1. Summary of Key Studies on ADHD and Addictive Behaviours 
Author (Year)     Study Population     Type of Addiction     Key Findings  
Simon et al. (2009)     Adults (meta-analysis)     Substance use     Higher prevalence of SUD in adults with ADHD 
Grassi et al. (2024)     Adults with ADHD     Behavioural addictions     Distinct clinical phenotypes with high impulsivity 
Bielefeld et al. (2017)     Adult case–control     Internet use disorder     Significant comorbidity between ADHD and IUD 
Davis et al. (2015)     Adult population     Multiple addictions     ADHD associated with personalityrelated addiction 
risk 

Methodology / Materials and Methods: The research will employ a narrative review approach, combine the viewpoints of the scientific and socioeconomic domains. The search will involve the selection of peerreviewed articles from the existing body of research in the fields of psychiatry and addiction, primarily focused on the topic of chronic adult ADHD, substance use disorder, behavioural addiction, and treatment outcomes. The preferences will include metaanalyses, longitudinal studies, and international consensus guidelines.

The inclusion of studies was done based on relevance regarding issues of comorbidity, functional impairment, treatment complexity, and possible implications in terms of costeffectiveness and productivity. Although a systematic review protocol was not used formally in this review, it was done in a structured manner consistent with principles found within PRISMA.

Results / Findings: Throughout the literature, ADHD has been found to be an important risk factor for both the development and severity of addictive behaviour s. The prevalence rate of lifetime substance use disorders and addictive behaviours tends to be significantly higher in persons suffering from ADHD than in those without the disorder. Comorbidity tends to be associated with early onset of substance use of substances, severity of symptoms, and co-occurrence of mental health problems. Moreover, research has pointed out the existence of a relationship between untreated ADHD and the use of addictive treatment services.

Table 2. Clinical Implications of ADHD–Addiction Comorbidity 
Domain     Observed Impact 
Age of onset     Earlier initiation of substance use 
Severity     Faster progression to dependence 
Treatment response     Reduced retention and poorer outcomes 
Psychiatric burden     Higher rates of mood and personality disorders 

Discussion: The results of this review shed light on the multifaceted association between ADHD and addictive behaviour . The neurobiological convergence, specifically the dysfunctionality of the dopaminergic reward pathways, provides a possible underlying mechanism that may contribute to a predisposition to developing addictive behaviour among people with ADHD. From a psychological perspective, the aspect of impulsivity and reduced executive function is closely associated with poor decision-making, poor compliance, and poor occupational performance.

From a managerial point of view, co-existing ADHD is a diagnostic and treatment challenge, especially where substance abuse clouds the presenting symptoms of ADHD. Medication management is not straightforward, given concerns about the misuse of stimulant drugs. However, evidence suggests that long-acting stimulant medications and non-stimulant alternatives used cautiously within carefully structured monitoring programs are effective. Combining pharmacological management with psychological and behaviour al approaches would seem crucial in improving not only the stability but also the employment retention outcomes.

Conclusion: There is ample evidence to suggest a link between ADHD and addictive behaviour. This not only poses high clinical, societal, and economic costs but also brings an onset of the disorder earlier in life, with more severe symptoms. With the simultaneous occurrence of two disorders, the responsiveness to treatments also diminishes. This increases health care costs and impacts productivity. It is high time that screenings be conducted as a norm in mental health care as well as addiction treatment setups. Moreover, treatment strategies need to be more personalized. By addressing ADHD symptoms as well as addictive behaviours simultaneously, it is possible to enhance your own as well as overall economic outcomes. 

Dr Hamid‑Reza Rahmanian is a Consultant Psychiatrist at South West London and St George’s NHS Trust, where he also serves as Associate Clinical Director for Sutton Community Mental Health Services. He is an Honorary Senior Lecturer at St George’s, University of London, where he contributes to undergraduate and postgraduate medical education, supervises research, and mentors trainees. He qualified as a medical doctor in 1998 and went on to complete specialist training in psychiatry,  gaining his CCT in General Adult Psychiatry in 2014. He is a fellow  of the Royal College of Psychiatrists (FRCPsych)  and has subspecialty experience in perinatal psychiatry.

Dr Rahmanian’s clinical interests span mood disorders, psychosis, ADHD, eating disorders, personality disorders, and neurodevelopmental conditions. He has a strong commitment to transcultural psychiatry and is fluent in Farsi, ensuring culturally sensitive assessments and treatments for diverse populations. His leadership work includes service redesign, quality improvement, and innovation in community psychiatry. He has recently led on transformation initiatives such as implementing a single consultant model and skill‑mix workforce strategies in community services. Dr Rahmanian is also actively involved in medical education, delivering lectures, supervising projects, and contributing to training programmes. His approach to psychiatry is holistic, grounded in the biopsychosocial model, and always aligned with NICE evidence‑based guidelines.