Statistics on ADHD Diagnosis in Adults

Recent studies have aimed to quantify the prevalence of ADHD persisting into or first appearing during adulthood. An estimated 8.7 million adults in the U.S. have ADHD. 

There are around 140 million adults worldwide who meet the criteria for persistent ADHD from initial childhood onset paired with continued significant impairment from symptoms as adults. Accounting additionally for adult cases without clear childhood history, the global prevalence of symptomatic ADHD regardless of onset age affects approximately 6.8% of adults.

While childhood ADHD recognition has risen, underdiagnosis remains prevalent among adults. Experts attribute this gap to adults having less regular contact with adept recognizers like teachers, and evolving symptom patterns being mistaken for other conditions like anxiety or mood disorders. There also remain cultural barriers around recognizing ADHD as a valid neurological disorder rather than just behavioral or motivational deficiencies.

Closing this adult diagnosis gap is crucial, as emerging research reveals untreated ADHD is strongly associated with negative outcomes like relationship instability, workplace performance issues, driving accidents, and risky behaviors involving alcohol or drugs. Given the high global burden, improving screening, diagnosis, and treatment rates for adult ADHD constitutes an important public health priority with immense potential to positively transform patient well-being and societal outcomes.

The Physical Health Connection

Research from the prestigious Karolinska Institutet published in The Lancet Psychiatry in 2021 revealed that adults with ADHD face a higher risk for a wide range of physical health conditions compared to adults without ADHD.

Analyzing over 4 million individuals in Swedish national registries, the large-scale study found adults with ADHD had a significantly increased likelihood of nervous system disorders, respiratory illnesses, musculoskeletal diseases, metabolic dysfunction and liver disease.

Specific physical conditions strongly associated with adult ADHD included:

  • Alcohol-related liver disease
  • Sleep disorders like insomnia
  • Chronic obstructive pulmonary disease (COPD)
  •  Epilepsy
  • Non-alcoholic fatty liver disease
  • Obesity

Additionally, small increased risks emerged for heart disease, Parkinson’s and dementia.

The patterns highlight serious concerns about medical management of co-occurring conditions in adults with ADHD, beyond just treating psychiatric symptoms. It suggests adopting an integrated, holistic approach that screens for and addresses physical health issues in ADHD patients as well.

While underlying genetic factors explained part of the risk, the study indicates lifestyle, medications or direct biological pathways may also connect ADHD with poorer physical health over time. Understanding these mechanisms can inform treatment planning to ultimately improve long-term well-being.

Generational Links and Dementia Risk

A striking discovery from another study by the Karolinska Institutet found a concerning link between ADHD and heightened dementia vulnerability across generations. Analyzing over 2 million individuals in Swedish national registries, the large-scale research showed parents and grandparents of those diagnosed with ADHD demonstrated a 34-55% higher risk of developing dementia compared to relatives of individuals without ADHD.

While not proving causation, this striking generational pattern hints at shared genetic variants or family environment factors that could jointly contribute to both ADHD and neurodegenerative disease risk later in life. The study also found the dementia risk specifically concentrated earlier in life for parents of ADHD individuals compared to typical onset ages.

This revelation emphasizes the mounting importance of proactively monitoring neurological health across generations where ADHD is present to enable early intervention if cognitive changes emerge. While the precise mechanisms connecting ADHD to accelerated dementia warrant further research, maintaining vigilant awareness across families can help detect any changes quickly.

Dementia Risk Amplified in Adults with ADHD

Adding to compelling connections with physical health and across family generations, a 2023 study from Rutgers University found that adults with ADHD were nearly 3 times more prone to eventually developing dementia compared to those without ADHD.

The 17-year longitudinal analysis followed over 100,000 older adults in Israel. It revealed that ADHD in later life manifests through neurological pathways reducing one's inherent capacity to compensate for cognitive decline typically seen in aging. This may accelerate vulnerabilities towards impairment.

Researchers emphasized the implications for clinicians working with older patients to proactively monitor any emerging attention or behavioral symptoms that could signal ADHD, rather than dismissing them as normal aging patterns. Early detection alongside optimized treatment may help slow progression.

Indeed, the study suggests ADHD medications themselves could modify disease trajectory by directly stimulating neural systems, though more research into specific pharmacological impacts is still needed. Overall, these findings highlight ADHD in aging adults as a potential risk factor for cognitive dysfunction requiring consistent screening and reveal opportunities for timely interventions promoting the longest healthy functioning possible.

Driving Safety Concerns

Moving from ADHD's links to cognitive decline, recent research also demonstrates acute everyday safety risks for aging adults with untreated ADHD symptoms.

A 2023 study from Columbia Mailman School of Public Health followed over 2,800 older drivers aged 65-79 for up to 4 years. It found a concerning pattern - those with ADHD showed substantially higher rates of unsafe driving outcomes.

Specifically, analyses revealed older adults with ADHD demonstrated:

  • 7% more frequent hard-braking events indicating delayed reaction times
  • Over twice the likelihood of reporting receiving traffic tickets
  • 74% increased chance of self-reported vehicle crash involvement

These risks persisted even after accounting for other health conditions, implicating ADHD directly.

Such findings underscore the pressing need to prioritize better recognition and clinical management of attention deficits among older adults to preserve safe mobility. As the US population ages, the number of older drivers is expected to reach 63 million in 2030. Identifying and treating issues like ADHD has immense potential to reduce accidents and improve public health.

Management and Public Health Implications

Together, these studies signal a critical need for enhanced clinical and public health strategies in managing adult ADHD. Healthcare providers are urged to take a comprehensive view when diagnosing and treating adults with ADHD, considering the associated risks for physical health conditions, cognitive impairments like dementia, and everyday safety concerns such as driving.

For individuals with ADHD or those caring for someone with the condition, it's essential to understand these risks and actively work with healthcare professionals to manage them. Treatments, including medication and lifestyle changes, can be tailored to mitigate these risks. For example, addressing ADHD in midlife may not only improve quality of life but also potentially decrease the risk of developing dementia later on.

Moreover, these studies illuminate the fact that ADHD can no longer be seen solely through the lens of childhood behavioral challenges. As the prevalence of adult ADHD diagnoses increases—thanks in part to better screening and awareness—the need for research on its long-term effects becomes ever more urgent. With approximately 8% of adults aged 18 to 44 years in the U.S. reported to have ADHD, and a notable prevalence even in older age groups, the public health implications are significant.


If you or someone you know has adult ADHD, it is important to stay informed about emerging research in this area. Speak with your doctor or seek help online to better understand the latest findings around associated health risks spanning from dementia to physical conditions. Advocate for comprehensive treatment plans that address ADHD along with related issues holistically. Also, promote more community awareness to overcome stigma. Adult ADHD is a real neurological condition that needs destigmatization and patient-centered medical care as well as public education. As research continues uncovering ADHD’s impacts later in life, maintaining open and empathetic dialogue offers hope for better outcomes through increased understanding and supportive resources.



Schein J, Adler LA, Childress A, et al. Economic burden of attention-deficit/hyperactivity disorder among adults in the United States: a societal perspective. Journal of Managed Care Specialty Pharmacy. 2022; 28(2): 168–179.

Song P, Zha M, Yang Q, et al. The prevalence of adult attention-deficit hyperactivity disorder: A global systematic review and meta-analysis. Journal of Global Health. 2021; 11: 04009.

Karolinska Institutet. "Adult ADHD is linked to numerous physical conditions, study finds." ScienceDaily. ScienceDaily, 7 July 2021.

Le Zhang, Ebba Du Rietz, Ralf Kuja‐Halkola, Maja Dobrosavljevic, Kristina Johnell, Nancy L. Pedersen, Henrik Larsson, Zheng Chang. Attention‐deficit/hyperactivity disorder and Alzheimer's disease and any dementia: A multi‐generation cohort study in Sweden. Alzheimer's & Dementia, 2021.

Stephen Z. Levine, Anat Rotstein, Arad Kodesh, Sven Sandin, Brian K. Lee, Galit Weinstein, Michal Schnaider Beeri, Abraham Reichenberg. Adult Attention-Deficit/Hyperactivity Disorder and the Risk of Dementia. JAMA Network Open, 2023; 6 (10).