Introduction

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental condition that globally affects ~ 5.6–7.6% of children (Salari et al., 2023) and ~3.1% of adults (Ayano et al., 2023). Recent years have seen a rise in ADHD diagnoses in many countries. This rise has prompted concerns that ADHD may be over-diagnosed. This article summarises the factors contributing to increased ADHD diagnoses and explores the complex reality of current diagnostic trends.

Factors Contributing to Rising ADHD Diagnoses

Several factors contribute to the rise in ADHD diagnoses. Together, these may help explain why more individuals are being identified today than in previous decades.

1. Broader Diagnostic Criteria

Many clinicians use the Diagnostic and Statistical Manual of Mental Health Disorders (DSM) when assessing ADHD. In its most recent edition, diagnostic criteria were broadened. Specifically:

• The symptom threshold was lowered for adults from 6 to 5
• The age of symptom onset increased from before 7 to before 12 years
• Dual diagnosis of ADHD and autism is now possible.

This broadened criteria have helped to improve detection of ADHD across the lifespan. However, they may have contributed to an increase is the number of people who meet criteria.

2. Increased Awareness

Public awareness of ADHD has surged in recent years. This is evidenced in:

• Increased online ADHD-related search activity
• Representation of ADHD-like traits in popular films and television
• Discussions on social media platforms (e.g., TikTok, Instagram, Reddit).

Greater awareness has helped people recognise longstanding difficulties and seek assessment. However, concerns have been raised about the spread of misinformation. A recent study found that more than half of ADHD-related content on TikTok contained misleading information (Yeung, Ng & Abi-Jaoude, 2022).

3. Reducing Stigma

Stigma surrounding mental health and neurodevelopmental conditions is slowly decreasing. Consequently, people feel more comfortable discussing difficulties and seeking assessment. In addition, parents, teachers, and employers feel more able to raise constructive concerns. These behavioural shifts may contribute to increased detection of existing cases (rather than a true increase in prevalence).

4. Greater Visibility

Modern education and workplace environments place high demands on executive function skills (e.g., attention, organisation, planning). Because many people with ADHD experience difficulties with these skills, such environments may increase the functional impact and visibility of their symptoms. This environmental mismatch may trigger some people to seek assessment earlier than previous generations.

The Complex Reality of ADHD Diagnostic Trends

Although concerns about over-diagnosis are common, research suggests that ADHD diagnoses trends are more complex. In fact, evidence indicates there are three trends occurring simultaneously across different populations (Abdelnour, Janson & Gold, 2022).

1. Under-Diagnosis

Under-diagnosis remains common. This is particularly the case among girls, woman, and individuals with inattentive ADHD presentations. These individuals may not fit traditional stereotypes of ADHD, and may have been overlooked for many years.

2. Over-Diagnosis

Over-diagnosis can occur. This is particularly the case among individuals who present with relatively mild symptoms. In these cases, normal variations in attention, activity levels, or behaviour may sometimes be interpreted as ADHD.

3. Misdiagnosis

Some ADHD symptoms overlap with other conditions (e.g., anxiety, depression, trauma-related difficulties, sleep disorders). Without a thorough assessment, it can be difficult to determine whether ADHD is the primary explanation for a person’s difficulties or whether another condition is contributing to similar symptoms.

Why a Simple Conclusion Is Not Useful

A growing number of researchers argue that excessive focus on ADHD over-diagnosis is counterproductive (Thapar, 2026). Doing so may increase stigma towards people seeking assessment and treatment. Those with genuine struggles may go undiagnosed or unsupported. This can have a significant negative impact on their mental health, social life, and work life.

 A more useful focus is on comprehensive assessment. These can reduce the likelihood of diagnostic errors. Key components include:

• Detailed developmental, educational, occupational, and mental health history
• Evaluation of symptoms across multiple settings and over time
• Consideration of alternative explanations and comorbid conditions
• Collateral information (e.g., parents, partners, school reports)
• Use of validated tools alongside clinical judgement.

Where possible, people should seek clinicians known to consistently adhere to best-practice ADHD assessment guidelines.

Conclusion

The prevalence of ADHD is on the rise. There are several factors contributing to this including: broader diagnostic criteria, increased awareness, reducing stigma, and increased visibility. Despite perceived over-diagnosis, research shows that ADHD continues to be under-, over-, and misdiagnosed. Instead of focusing on over-diagnosis, it is more productive to focus on supporting comprehensive assessment and individualised support.

References

Abdelnour, E., Jansen, M. O., & Gold, J. A. (2022). ADHD diagnostic trends: increased recognition or overdiagnosis?. Missouri Medicine, 119(5), 467.

Ayano, G., Tsegay, L., Gizachew, Y., Necho, M., Yohannes, K., Abraha, M., … & Alati, R. (2023). Prevalence of attention deficit hyperactivity disorder in adults: Umbrella review of evidence generated across the globe. Psychiatry Research, 328, 115449.

Salari, N., Ghasemi, H., Abdoli, N., Rahmani, A., Shiri, M. H., Hashemian, A. H., … & Mohammadi, M. (2023). The global prevalence of ADHD in children and adolescents: a systematic review and meta-analysis. Italian Journal of Pediatrics, 49(1), 48.

Thapar, A. (2026). Editorial Perspective: Overdiagnosis of ADHD? Here we go again. Child and Adolescent Mental Health, 31(2), 153–155.

Yeung, A., Ng, E., & Abi-Jaoude, E. (2022). TikTok and attention-deficit/hyperactivity disorder: a cross-sectional study of social media content quality. The Canadian Journal of Psychiatry, 67(12), 899–906.