Signs And Symptoms Of Undiagnosed ADHD

Medically reviewed by Melissa Guarnaccia, LCSW and Julie Dodson, MA, LCSW
Updated November 28, 2024by BetterHelp Editorial Team

Attention-deficit/hyperactivity disorder (ADHD) is a psychiatric illness that typically begins before 12 years of age. Diagnosing ADHD can be important because the disorder may interfere with a child's development, social life, and school performance. 

Untreated ADHD in adults can contribute to problems with work performance, family life, driving safety, and overall well-being. Undiagnosed adult ADHD also tends to be linked to a greater risk of substance use disorder, hospitalization, and incarceration. 

Signs and symptoms of undiagnosed ADHD

Experts estimate that about 20% of adults who have ADHD are diagnosed. This could mean that about 80% of adults with ADHD do not know they have the disorder and, as a result, may not be receiving treatment. Undiagnosed ADHD may be displayed through restlessness, impulsivity, a wandering mind, forgetfulness, and procrastination. These symptoms can be addressed through interventions like doctor-prescribed medication and therapy.

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Restlessness

The childhood stereotype of ADHD usually involves intense hyperactivity. People often think of a kid with ADHD as being unable to sit down for long and instead running around, racing from one thing to the next, and talking loudly. While this stereotype can hold true for some kids with ADHD, it isn’t necessarily true for all children with the disorder or for most adults with ADHD. In particular, girls and women tend to be less likely to show signs of hyperactivity and may not be diagnosed as a result.

Undiagnosed ADHD may show subtle increased energy

Many people with undiagnosed ADHD experience increased energy but don't display it as obviously as others might expect. Instead of acting "hyper," a person with ADHD may show signs of restlessness. For example, they may bounce their leg or fidget with a pen in their hand while at school or work. After extended periods of sitting, they may find excuses to stand up and walk around, such as by going to the bathroom.

The restlessness of a person with ADHD may also be displayed through high activity levels. This could be through an immensely active social life, or regular, intense exercise. Movement is often preferred to being still by people with ADHD because it can provide an outlet for energy and restlessness.

Impulsivity

In some cases of ADHD, especially in adults, hyperactivity may show itself through impulsivity. In these cases, a person might not act in ways that others consider to be "hyper," but they may make impulsive choices. 

Impulsivity can be seen in multiple ways

Impulsivity can be seen in multiple ways, and these ways often differ among people with ADHD. For example, one person's impulsivity could come out in the form of speaking impulsively. Maybe they are "unfiltered" and say things that others view as rude, or they might overshare personal information and regret it later. 

Another person's impulsivity could come out through rash decisions. They may impulsively spend money on items they later realize they don't need, impulsively eat foods that look appealing even though they aren't hungry, or impulsively show their irritation with a minor situation that is making them impatient.

Mind wandering

People often think of ADHD as involving a person's behaviors, but it usually involves their thought patterns, too. Sometimes, people with ADHD can be distracted by their own mind wandering rather than by something in their environment. Mind wandering can make day-to-day life difficult and frustrate others, like family members or coworkers, who may believe the mind-wanderer doesn't listen to them or doesn't remember the things they say.

Spacing out: Distraction by thoughts in inattentive ADHD

The tendency to be distracted by one's thoughts can be most common among people who have the inattentive subtype of ADHD. People with inattentive ADHD do not usually have abnormal levels of hyperactivity or impulsivity. They may often find themselves "spacing out" and mentally checking out from their environment in order to daydream, reminisce, or think of something else that they find more interesting. Mind wandering usually isn't a conscious choice, and it can lead to other concerns, like forgetfulness.

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Forgetfulness 

People with ADHD generally struggle with working memory compared to those without ADHD. These memory challenges can show up as forgetfulness or absent-mindedness. People with ADHD may regularly misplace necessary items, like their phone or keys, because they've forgotten where they set them down. They may also lose track of or forget to bring needed items with them, such as forgetting to bring homework with them to school. When someone with ADHD regularly makes these types of mistakes and it impacts their school or work performance, they may also experience low self-esteem.

Chronic tardiness due to forgetfulness from ADHD symptoms

ADHD forgetfulness can also cause a person to be habitually late. They may forget that they have somewhere to be or fail to give themselves enough time to get ready and commute. This can be frustrating for others, who may even joke about it. Some people with ADHD are known to their friends and family as being "always late," without anyone in the situation recognizing the chronic tardiness as a symptom of an underlying disorder.

Procrastination

People with ADHD are sometimes said to have an "interest-based nervous system." This phrase generally means that a person with ADHD doesn't necessarily struggle to focus in general, but that they struggle to focus on things in which they aren’t interested.

Spending their time on activities they enjoy

As a result, a person with ADHD may end up spending their time on activities they enjoy, like their hobbies, at times when they would be better served doing something else. Schoolwork, professional work, housekeeping, and other less exciting tasks may be relegated to the back burner time and again by both children and adults with ADHD.

Sometimes, people procrastinate until an impending deadline is close enough that they cannot procrastinate any longer. Then, they may hyperfocus and do all the work that should've been done over a long time period in a very short block of time. This habit can cause difficulties at work, school, and home. Others may assume the procrastinating person with ADHD is choosing to shirk responsibilities or doesn't care about the work at hand, when the reality may be that, without treatment, they may not be able to motivate themselves to focus on less interesting tasks until the threat of a deadline looms overhead.

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Seeking mental health treatment for attention deficit hyperactivity disorder (ADHD)

If you suspect you have ADHD, consider seeking treatment. Treatment for ADHD can make managing life much easier and improve mental health and well-being. The two most frequently recommended treatments for ADHD tend to be medication and therapy.

Signs and symptoms of undiagnosed ADHD: Online mental health treatment 

Online therapy may be a particularly useful treatment option for ADHD. It can be a complementary treatment for those on ADHD medication or a standalone treatment for those who can't tolerate or prefer not to take medication. 

Flexibility of online therapy

With online therapy, you can meet with a therapist from your home or anywhere you find convenient. This flexibility may make attending sessions easier, as it doesn't require a mad dash to travel to another location in order to receive professional help. 

Effective online treatment for attention deficit hyperactivity disorder (ADHD)

A 2022 meta-analysis of six research studies showed that online therapy could be an effective treatment for ADHD and could be particularly beneficial in improving attention deficit and social function.

Takeaway

Up to 80% of adults with ADHD may remain undiagnosed and, as a result, untreated. Untreated ADHD is often linked to difficulties with work, family, social life, substance use, and overall well-being. People with undiagnosed ADHD do not necessarily appear "hyper" in the way others may expect based on stereotypes. Instead, they may be restless, impulsive, and forgetful. They may also experience a wandering mind and a propensity for procrastination. Treatments like medication and online therapy are available to help and can be life-changing for some people with ADHD.
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