Why Some Adults Never Get Diagnosed

Discover tips, treatment options, and support strategies from the Finding Focus Care Team

Last Update: May 12th, 2025 | Estimated Read Time: 8 min

Introduction: Unrecognised ADHD in Adulthood

Attention-Deficit/Hyperactivity Disorder (ADHD) is often perceived as a childhood condition, primarily associated with visible hyperactivity in young males. However, ADHD is a lifelong neurodevelopmental disorder, and a substantial proportion of individuals continue to experience symptoms well into adulthood. Despite this, a significant number of adults with ADHD remain undiagnosed, with international data suggesting that the majority may never receive formal identification or treatment (Kooij et al., 2010).

This oversight has considerable implications. Adults with undiagnosed ADHD often report difficulties in occupational performance, emotional regulation, and interpersonal relationships, yet they frequently attribute these struggles to character flaws or moral failings. This article explores the multifactorial reasons why ADHD frequently goes undiagnosed in adulthood, with a particular emphasis on systemic, psychological, and developmental factors.

Symptom Evolution and the Subtle Presentation in Adults

The Changing Face of ADHD

In adults, ADHD often manifests in less overt ways compared to childhood presentations. Hyperactivity may be replaced by internal restlessness or a chronic inability to relax. Core symptoms such as inattention, disorganization, and poor time management are more prevalent, yet these are often misinterpreted as laziness or irresponsibility.

Neuroimaging studies have shown that individuals with ADHD typically demonstrate reduced activation in the prefrontal cortex, an area critical for executive functions such as planning, attention regulation, and impulse control. These neurological differences contribute to ongoing difficulties in task prioritization, working memory, and goal-directed behaviour, even in high-functioning adults (Arnsten & Rubia, 2012).

Such symptoms are often internalized, especially when individuals develop compensatory strategies to mask their impairments. These strategies may delay recognition of the disorder until the individual's life becomes too complex or the coping mechanisms fail under increased pressure.

Sociocultural and Diagnostic Barriers

Gendered and Racial Diagnostic Bias

ADHD has historically been underdiagnosed in populations who do not fit the stereotypical profile. Research has consistently shown that women are less likely to receive a timely diagnosis. Their symptoms, typically rooted in inattention and emotional dysregulation, are often mislabelled as anxiety, depression, or even personality disorders.

Furthermore, diagnostic disparities are also evident across cultural and racial groups. Studies indicate that racialized individuals may experience additional obstacles in accessing mental health services, including under-referral, clinician bias, and culturally incongruent assessment tools. These systemic issues contribute to delayed or missed diagnoses, particularly in adults who were not assessed during childhood (Coker et al., 2016).

Comorbidity and Misdiagnosis

The Overlap with Mood and Anxiety Disorders

One of the most significant challenges in diagnosing adult ADHD lies in its overlap with other psychological conditions. Adults with ADHD frequently report symptoms of depression, anxiety, or chronic stress, conditions that may emerge as secondary responses to untreated ADHD. However, because these emotional symptoms are more readily recognizable to clinicians, they are often diagnosed in isolation, with the primary neurodevelopmental disorder remaining obscured.

This diagnostic overshadowing contributes to treatment approaches that may alleviate surface-level distress while leaving the underlying executive dysfunction unaddressed. Moreover, it reinforces the self-perception that individuals are simply “not trying hard enough,” rather than experiencing a legitimate neurological condition.

Clinical Markers and Self-Recognition

Identifying the Red Flags

Although ADHD in adults can be subtle, certain behavioural patterns frequently emerge:

• Chronic difficulties with time management and organization
  
  
• Persistent procrastination and task avoidance
  
  
• Emotional volatility or sensitivity to criticism
  
  
• Poor follow-through despite strong intentions
  
  
• A lifelong pattern of underachievement relative to potential
  

When viewed in isolation, these patterns may appear circumstantial. However, when they are consistent across multiple domains of life, occupational, relational, and personal, they warrant further assessment.

The Adult ADHD Self-Report Scale (ASRS) and similar structured tools can provide preliminary insight. Nonetheless, comprehensive diagnostic evaluations should involve developmental history, collateral information, and assessment of functional impairments across settings.

Moving Towards Diagnosis and Intervention

Breaking the Cycle of Misunderstanding

Receiving a diagnosis in adulthood can be both validating and transformative. It allows individuals to reinterpret lifelong challenges not as personal deficiencies, but as manifestations of a clinically recognized condition. This shift in perspective facilitates access to evidence-based treatments, including stimulant and non-stimulant medication, cognitive-behavioural therapy, and ADHD-specific coaching interventions (Kessler et al., 2006).

Crucially, diagnosis is not a label, it is a framework that enables targeted support, improved self-understanding, and the development of adaptive strategies. In the context of adult ADHD, timely identification serves as a powerful first step toward restoring agency and quality of life.

Conclusion: From Misunderstood to Recognized

ADHD in adulthood remains significantly underdiagnosed due to evolving symptomology, societal misconceptions, and systemic inequities in mental health care. Recognizing the nuanced ways in which ADHD presents in adults is essential for reducing misdiagnosis, improving access to treatment, and empowering individuals to seek appropriate support.

While the path to diagnosis may be complex, it offers clarity and a renewed sense of possibility. For those who see their own experiences reflected in this discussion, professional evaluation can be a valuable step toward greater self-awareness and functional improvement.

Finding Focus Care Team

We are a group of nurse practitioners, continuous care specialists, creators, and writers, all committed to excellence in patient care and expertise in ADHD. We share content that illuminates aspects of ADHD and broader health care topics. Each article is medically verified and approved by the Finding Focus Care Team. You can contact us at Finding Focus Support if you have any questions!  

References

Arnsten, A. F. T., & Rubia, K. (2012). Neurobiological circuits regulating attention, cognitive control, motivation, and emotion: Disruptions in neurodevelopmental psychiatric disorders. Journal of the American Academy of Child & Adolescent Psychiatry, 51(4), 356–367. Link  

Coker, T. R., Elliott, M. N., Kataoka, S., Schwebel, D. C., Mrug, S., Grunbaum, J. A., ... & Schuster, M. A. (2016). Racial and ethnic disparities in ADHD diagnosis and treatment. Journal of Developmental & Behavioural Pediatrics, 37(7), 469–477. Link  

Kessler, R. C., Adler, L., Barkley, R., Biederman, J., Conners, C. K., Demler, O., ... & Zaslavsky, A. M. (2006). The prevalence and correlates of adult ADHD in the United States: Results from the National Comorbidity Survey Replication. American Journal of Psychiatry, 163(4), 716–723. Link  

Kooij, J. J. S., Bijlenga, D., Salerno, L., Jaeschke, R., Bitter, I., Balázs, J., ... & Asherson, P. (2019). Updated European Consensus Statement on diagnosis and treatment of adult ADHD. European Psychiatry, 56, 14–34. Link