Undiagnosed ADHD in Adults: Signs, Risks, and Why It Matters

Around 6% of adults have ADHD, but less than 20% of them receive the care and treatment they need.^[1]

This goes to show that many adults live with undiagnosed ADHD, are often unaware of how much it impacts their lives. 

ADHD can make it difficult for individuals to complete tasks, meet deadlines, and control impulses. Without proper support or treatment, this condition can be an invisible weight that holds them back from reaching their goals.

If you have undiagnosed ADHD, it’s easy to blame yourself or think you’re just not trying hard enough. But the fact is that ADHD is a real medical disorder affecting the brain. The difficulties you face don’t reflect your character or abilities — they’re simply the result of untreated symptoms of ADHD. 

The good news is that a proper diagnosis can be transformative. It opens the door to support and treatment, empowering you to overcome your challenges and reach new milestones in your life. 

What Is Undiagnosed ADHD?

Undiagnosed ADHD refers to attention-deficit/hyperactivity disorder (ADHD) that a medical professional has not formally diagnosed. ADHD is a condition affecting the brain marked by symptoms of inattention, hyperactivity, or impulsivity.

ADHD in adults often goes unnoticed because its symptoms can be subtle or mistaken for personality traits. Behaviors like excessive talking might be labeled as being a “chatterbox,” or procrastination could be seen as laziness.

How Does ADHD Go Undiagnosed in Adults?

There are different reasons why ADHD is more likely to go undiagnosed in adults.

ADHD often looks different in adults than in children, which makes it harder to detect. Many people associate ADHD with hyperactivity, but this symptom often changes as the individual gets older.

Symptoms of hyperactivity tend to wane, subside, or become more subtle with age.^[2] In children, outbursts of energy are common. In contrast, adults may experience constant restlessness or the need to always be on the go.^[3]

Without this understanding, adults may dismiss the possibility of having ADHD due to the absence of obvious hyperactive behaviors.

Additionally, many adults have built coping mechanisms over the years of having the same struggles. Some of these strategies may help them mask their ADHD symptoms. For example, an ADHDer might work twice as hard as their peers to get to where they’re at. This high-functioning ADHD can make it harder to recognize and spot symptoms of ADHD.

ADHD also commonly co-occurs with other mental health disorders. Research suggests that up to 80% of adult ADHDers may have another disorder alongside their ADHD, including anxiety, tics, and depression.^[4]

This can make diagnosis even more tricky, as they may be diagnosed for one condition while the other is overlooked. 

Types of ADHD and How They Manifest in Adults

ADHD can affect adults in different ways. 

Based on a person’s symptoms, they may be diagnosed with any of the three main types of ADHD. These include:^[5]

• Predominantly inattentive: If you have ADHD-PI, you’ll find it difficult to focus, remember details, follow instructions, and keep up in conversations. You might be forgetful, misplace important items, and have trouble with organization and planning. While hyperactivity or impulsivity can still occur, the main challenge is inattention. 
• Predominantly hyperactive/impulsive: Children may be unable to keep still, constantly run around, or squirm about. In adults, this may look more like fidgeting, being unable to wait their turn, interrupting others, always being on the go, or feeling restless. Inattention may also be present. However, hyperactivity and impulsivity are much more prominent in this subtype.
• Combined type: Adults with this type of ADHD experience significant symptoms of both inattention and hyperactivity or impulsivity. 

For a diagnosis, you’d have to experience symptoms of ADHD for 6 months or more. Your symptoms will also be present in two or more areas of your life, such as at work, school, home, or in your relationships. 

Signs of Undiagnosed ADHD in Adults

Symptoms of undiagnosed ADHD can significantly affect different areas of your life. They might impact your productivity or performance at work or make it difficult to communicate well in relationships. 

Recognizing the signs in yourself or a loved one is an essential first step toward change. By identifying these symptoms, you can start to address them and minimize the impact of ADHD. 

Emotional and Behavioral Indicators of ADHD

ADHD can change the way you process, regulate, and express your emotions.^[6] It can also cause impulsivity or hyperactivity.

Some emotion-related indicators of ADHD include:^[7]

• Having mood swings
• Being emotionally sensitive
• Getting irritated or frustrated over small things
• Easily over-excitable
• Quick to anger or argumentative
• Having emotional responses that feel disproportionate to the situation

Hyperactivity and impulsivity can lead to behaviors and symptoms such as:^[5]

• Making hasty or impulsive decisions
• Engaging in risky behaviors, like speeding
• Interrupting others or finishing their sentences
• Being unable to wait your turn in conversations
• Intruding or taking over what others are doing 
• Fidgeting and being unable to sit still
• Leaving your seat during inappropriate times
• Always on the go 

Cognitive and Organizational Struggles

Because ADHD alters the way your brain processes information, you may experience the following symptoms:^[5]

• Struggling to remember details and follow through on instructions
• Being forgetful in daily life, such as forgetting appointments, errands, or tasks
• Experiencing mental overload or ADHD paralysis
• Poor organizational skills
• Difficulty with planning
• Misplacing important items
• Running late or failing to meet deadlines due to time blindness
• Experiencing ADHD brain fog or mental exhaustion 
• Challenges with problem-solving or adapting to different situations

Focus and Motivation Challenges

ADHD is linked to structural and chemical differences in the brain. Undiagnosed ADHD can contribute to challenges with focus and motivation. 

Some of these struggles include:^[5]

• Trouble maintaining focus, especially with routine or boring tasks
• Getting easily distracted
• Difficulty focusing in conversations
• Avoiding or being reluctant to engage in tasks that require sustained focus
• Lacking the motivation to start or complete tasks
• Procrastinating despite looming deadlines

Every individual experiences a few of the above symptoms from time to time. But for an actual ADHD diagnosis, you’d have to notice multiple symptoms that are persistent and appear in different areas of your life. 

What Does Undiagnosed ADHD Look Like in Adults?

Undiagnosed ADHD can be quite disruptive in your day-to-day. 

It can prevent you from performing at your best at work or school, making you wonder why you work so much harder than your peers to catch up. Additionally, balancing chores, running errands, or managing responsibilities might feel overwhelming. 

ADHD can also contribute to conflicts and misunderstandings in relationships. It can be challenging to communicate well, process emotions, and express them in a regulated manner. You may also find socializing, reading, and interpreting body language difficult. This can make it challenging to build and sustain healthy relationships.

It’s easy to feel at fault for these challenges you’re experiencing. But ADHD is not a reflection of your character—it’s a medical disorder. Understanding this is the first step toward building self-compassion and overcoming the shame or fear of seeking help.

Why Diagnosing ADHD Matters

Getting ADHD diagnosed is a crucial step that allows you to get treatment and support for the condition. 

For many adult ADHDers, ADHD treatment is effective in helping improve their symptoms and enhancing their quality of life. 

The Benefits of Identifying and Treating Adult ADHD

Many adults find that treatment is effective in reducing symptoms. 

ADHD medications are sometimes used in the treatment plan for adult ADHD. The first line of treatment is stimulant medications. These help to balance and regulate the levels of chemical messengers in your brain. 

Research shows the following benefits are associated with using ADHD medication:^[8][9]

• Improved symptoms of inattention
• Reduced hyperactivity and impulsivity
• Reduced risk of depression and suicide
• Lower risk of reckless behavior and injuries
• Less risk of substance use disorder
• Better employment rates

Apart from medications, there are also ADHD therapy options, which can help improve the efficacy of your treatment. 

One of the most popular forms of therapy is called cognitive behavioral therapy. During these sessions, you’ll explore unhelpful thinking patterns with your therapist. You’ll also work together to find ways to create more positive and healthy mindsets. 

Researchers have found that CBT can improve ADHD symptoms, minimize unhealthy self-beliefs, and lower depressive symptoms.^[10]

A combination of therapy and treatment can further improve the outcome of ADHD treatment. 

How a Proper Diagnosis Can Change Lives

Many adults with ADHD have found that a proper diagnosis is life-changing. Getting diagnosed with ADHD can be daunting, but it can also provide relief and answers to the constant struggles you may be facing. 

Understanding ADHD can shift how you see yourself and your challenges. This helps you replace feelings of failure or frustration with self-awareness and increased confidence.

With support and treatment, you put yourself in the best position to achieve your personal goals. You’ll be better equipped to tackle challenges at home, work, or in your relationships, which can improve your quality of life. You’ll likely also experience better mental health and have a lower risk of developing anxiety or depression. 

It’s Never Too Late to Get Diagnosed for ADHD

An ADHD diagnosis can make a huge difference, no matter your age. Adults may experience even greater benefits from a proper diagnosis and treatment. 

To get your symptoms assessed, you can either contact your doctor for a referral or go directly to a specialist who has experience working with adult ADHDers. If a diagnosis is made, your healthcare professional can recommend management options like medication, therapy, or even ADHD coaching. 

Want to learn more about the signs and symptoms of ADHD? ADDA+ is a resource center that offers materials, webinars, and courses designed by experts to help adult ADHDers better understand the condition. Through ADDA+, you can also connect with other adult ADHDers to share your experiences and exchange advice. 

References

[1] Staley BS, Robinson LR, Claussen AH, et al. Attention-Deficit/Hyperactivity Disorder Diagnosis, Treatment, and Telehealth Use in Adults — National Center for Health Statistics Rapid Surveys System, United States, October–November 2023. MMWR Morb Mortal Wkly Rep 2024;73:890–895. DOI: http://dx.doi.org/10.15585/mmwr.mm7340a1

[2] Rivas-Vazquez, R. A., Diaz, S. G., Visser, M. M., & Rivas-Vazquez, A. A. (2023). Adult ADHD: Underdiagnosis of a Treatable Condition. Journal of Health Service Psychology, 49(1), 11–19. https://doi.org/10.1007/s42843-023-00077-w

[3] Ginapp, C. M., Macdonald-Gagnon, G., Angarita, G. A., Bold, K. W., & Potenza, M. N. (2022). The lived experiences of adults with attention-deficit/hyperactivity disorder: A rapid review of qualitative evidence. Frontiers in Psychiatry, 13, 949321. https://doi.org/10.3389/fpsyt.2022.949321

[4] Seo, J.-C., Jon, D.-I., Shim, S.-H., Sung, H.-M., Woo, Y. S., Hong, J., Park, S., Seo, J. S., & Bahk, W.-M. (2022). Prevalence and Comorbidities of Attention Deficit Hyperactivity Disorder Among Adults and Children/Adolescents in Korea. Clinical Psychopharmacology and Neuroscience, 20(1), 126–134. https://doi.org/10.9758/cpn.2022.20.1.126

[5] de la Peña, I. C., Pan, M. C., Thai, C. G., & Alisso, T. (2020). Attention-Deficit/Hyperactivity Disorder Predominantly Inattentive Subtype/Presentation: Research Progress and Translational Studies. Brain sciences, 10(5), 292. https://doi.org/10.3390/brainsci10050292

[6] Siham Albesisi, & Overton, P. G. (2023). Relationship Between ADHD-Like Traits and Emotion Dysregulation in the Adult General Population. Advances in Neurodevelopmental Disorders. https://doi.org/10.1007/s41252-023-00381-y

[7] Shaw, P., Stringaris, A., Nigg, J., & Leibenluft, E. (2014). Emotion dysregulation in attention deficit hyperactivity disorder. The American journal of psychiatry, 171(3), 276–293. https://doi.org/10.1176/appi.ajp.2013.13070966

[8] Cortese S. (2023). Evidence-based prescribing of medications for ADHD: where are we in 2023?. Expert opinion on pharmacotherapy, 24(4), 425–434. https://doi.org/10.1080/14656566.2023.2169604

[9] Taipale, H., Bergström, J., Gèmes, K., Tanskanen, A., Ekselius, L., Mittendorfer-Rutz, E., & Helgesson, M. (2024). Attention-Deficit/Hyperactivity Disorder Medications and Work Disability and Mental Health Outcomes. JAMA network open, 7(3), e242859. https://doi.org/10.1001/jamanetworkopen.2024.2859

[10] Pan, M. R., Dong, M., Zhang, S. Y., Liu, L., Li, H. M., Wang, Y. F., & Qian, Q. J. (2024). One-year follow-up of the effectiveness and mediators of cognitive behavioural therapy among adults with attention-deficit/hyperactivity disorder: secondary outcomes of a randomised controlled trial. BMC psychiatry, 24(1), 207. https://doi.org/10.1186/s12888-024-05673-8