10 Scientifically Backed Signs of ADHD in Adults

ADHD, or Attention-Deficit/Hyperactivity Disorder, has long been associated with children who are unable to sit still or concentrate. In reality, however, ADHD frequently lingers into adulthood. The signs in adulthood also appear to be quite different in various contexts.

As a result, it becomes more difficult to diagnose.

So, in this article, I will attempt to detail 10 signs of ADHD in adults. Understanding these adult-specific symptoms is critical for a prompt diagnosis and appropriate therapy.

Recent research emphasizes that adult ADHD is best understood by examining how it impairs a person it in daily life. These contexts of impairments are related to work, relationships, safety, and emotional regulation.

Here are 10 scientifically supported indications of ADHD in adults, based exclusively on information from peer-reviewed sources:

1. Chronic Disorganization and Poor Time Management

Adults with ADHD often struggle to maintain organized routines. Managing their time properly can remain an ongoing battle for them.

Due to this, they can form a distressing habit of missing deadlines, misplacing essential documents, and underestimating the time required to complete activities (Kosheleff et al., 2023; Rauf et al., 2024). These issues frequently interfere with job performance and daily functioning.

Moreover, it can lead to even further stress later on as the lack of timeliness builds up pending tasks. At this point, the habit of procrastination can add to the burnout as well.

2. Inattention That Affects Work and Daily Life

Inattention in ADHD extends beyond the occasional distraction. Adults with this problem may struggle to focus during meetings, read lengthy documents, or accomplish tasks that require persistent mental effort (Thapar et al., 2017; Rauf et al., 2024). Kosheleff et al. (2023) discovered that this form of inattention is a significant contributor to work-related impairment.

Further problems can also arise, especially disillusionment with colleagues and family members. This is because many people assume, incorrectly, that this inattention is simply a case of carelessness. As such, adults with ADHD could be labelled as uncaring or too irresponsible.

Labelling, in turn, could lead to a greater loss of attention because of the stress that it may cause.

3. Impulsivity in Social and Financial Decisions

Adults with ADHD can be quite impulsive. They might make purchases right on the spot or have a habit of interrupting conversations. They might even abruptly change employment – seemingly out of nowhere. This is another way they might harm financial stability and social relationships (Dobrosavljvic et al., 2023; Kosheleff et al., 2023).

Again, much of this mode of behavior could be perceived as the individual being irresponsible. However, it can also damage social credibility by making such individuals appear to be unpredictable. Often, organizations and families want to make sure they rely on someone who is predictable, especially in the higher offices.

This is one reason why even highly capable ADHD individuals might not be considered for such posts or jobs.

Very similarly, family members can feel insecure due to impulsive decisions. This is especially the case in matters related to finances, social etiquette and relations.

4. Emotional Dysregulation and Low Frustration Tolerance

Emotional stability is an often neglected but very prevalent problem for adults with ADHD. Adults may have frequent mood swings, get easily upset, or struggle to control their anger (Rauf et al., 2024; Thapar et al., 2017). Dobrosavljvic et al., (2023) also identify emotional instability as a crucial characteristic.

Emotional instability in ADHD can result in an overreactive response to rewards, even during bad moods (something which ADHD shares with borderline personality disorder) (Petrovic & Castellanos, 2016). This only further increases the individual’s dysregulation of moods and emotions.

Furthermore, high emotional reactivity could also lead to people with ADHD feeling emotionally drained – more than the average person.

5. Restlessness and Internal Hyperactivity

This is one of the classic signs of ADHD. While toddlers exhibit this usually by running around or climbing excessively, adults experience restlessness in more subtle ways. Adults might feel being always “on edge,” tapping fingers, or unable to relax (Rauf et al., 2024; Thapar et al., 2017).

Restlessness has been associated with higher functional connectivity in the brain (Sörös et al., 2019). What this means is that information received and relayed from all over the brain is processed in more areas, more rapidly, than it is in the average person.

As a result, the brain of the person with ADHD is generally more active than the average.

Consequently, such neurodivergent individuals feel more restless, trying to dispense with this energy in ways that are possible. Others might see this restlessness as a symptom of anxiety.

It could certainly be that.

However, this can often be a case of mislabeling where the actual underlying problem is of hyperactivity.

6. Frequent Job Changes and Career Instability

Problems with impulsivity and an inability to deal with others and one’s own emotions could end up contributing to further problems. This is the case with adults with ADHD.

They may frequently change employment owing to dissatisfaction, interpersonal difficulties, or impulsive behavior. According to Kosheleff et al. (2023), this volatility can result in long-term job challenges and decreased income. Switching jobs too hastily can put off many future employers who want employees to demonstrate resilience.

It is not the case that people with ADHD are less resilient. Rather, out of habit, impulsivity and the problems discussed above, the person might opt out of jobs hurriedly.

Functionally, however, as discussed above, such resignations and withdrawals pose big issues to one’s career.

7. Strained Interpersonal Relationships

Adults with ADHD may struggle to maintain healthy relationships. These difficulties can lead to frequent misunderstandings, disputes, and a perceived lack of reliability (Kosheleff et al., 2023; Thapar et al., 2017). Usually, these conflicts stem from misconceptions of the person’s inattention, impulsivity, and lack of emotional control.

Nevertheless, all of these areas do in fact contribute to the building of trust in relationships. The problem lies in that breaking a habit is one thing, treating genuine psychomotor issues is another. Thus, for the friends of family of someone with ADHD, it can be incredibly frustrating to see this person not being able to do things they consider basic.

Well, it is often equally – if not more – frustrating for the person with ADHD. Many individuals, despite having insight, find it extremely hard to control their hyperactivity and impulsivity due to the fact that it seems inescapable.

This frustration unfortunately contributes even further to conflicts with friends, family and work colleagues.

8. Increased Risk of Accidents and Safety Violations

This is a rather dire problem associated with ADHD. Adults with this condition are more likely to be involved in accidents, particularly motor vehicle collisions. The underlying causes here are of distractibility, poor focus, and impulsive driving behaviors (Dobrosavljevic et al., 2023; Rauf et al., 2024). Moreover, Sadeghi-Bazargani et al. (2019) found an association between risky motorcycle behavior and ADHD.

There are other equally crucial contributors to this incidence of road accidents (Brunkhorst-Kanaan et al., 2021). For one, sleep disturbances can be a major issue. Secondly, people with ADHD who have other disorders too (commorbidity) have a higher chance of safety violations and accidents. In particular, substance use disorders further increase this rate.

9. Sleep Disturbances

Hyperactivity can cause difficulty with sleep. In particular, adults with ADHD find it hard to go to sleep, remain asleep, or even feel relaxed after waking up. Rauf et al. (2024) identify sleep disruption as a prevalent but generally neglected symptom.

Sleep disturbances also exacerbate other ADHD symptoms. Voinescu et al. (2012) noted that while impulsivity was linked to poor sleep, inattention was linked to both insomnia and being evening-oriented (being most active in the evening). Moreover, poor sleep was also linked to hyperactivity and timing of sleep.

Thus, sleep disturbances are not only a sign of ADHD, but rather a maintaining factor of the condition too.

10. Co-occurring Mental Health Conditions

Usually, when an individual has one psychological disorder, there is a chance that they might have others too. While this is not unique to ADHD, comorbid disorders such as anxiety, depression, and substance abuse are more common in adults with ADHD. These frequently confound diagnosis and therapy, but their prevalence should raise clinical suspicion of underlying ADHD (Rauf et al., 2024; Lovett & Harrison, 2021).

Often when there are multiple mental disorders at play, they can have a compound effect. This means that these conditions can amplify each other’s negative effects. I gave examples of this earlier on in this article, with regards to substance abuse and sleep disorders.

Why These Signs Matter

In the modern world, our understanding of neurodevelopmental issues has deepened. Long gone are the days of only depending on checklists to see what problems people have.

Rather, current ADHD diagnosis emphasizes how symptoms affect functioning. Lovett and Harrison (2021) contend that informant reports and performance validity assessments are critical to avoiding misdiagnosis. What might appear ADHD to some, might actually turn out to be a completely different condition. Rauf et al. (2024) note that many individuals go untreated due to compensatory mechanisms or symptoms that overlap with other illnesses.

It’s better to be safe than sorry.

Early detection and diagnosis can improve long-term consequences. Untreated ADHD can lead to a whole myriad of problems. These include – but are not limited to – academic underachievement, job loss, relationship breakdowns, and an increased risk of accidents (Thapar et al., 2017; Dobrosavljevic et al., 2023).

As such, seeking the right treatment as early as possible could be a life-changing decision. While neurodevelopmental conditions can be chronic, the benefits of the right psychotherapy and pharmacological interventions are more than established. Not only could they improve psychiatric symptoms, but they could also drastically improve quality of life.

Conclusion

Adult ADHD is very real. Unfortunately, it continues to be frequently undetected, despite how much it impacts the life of the people who have it. There are many signs, as discussed above, including emotional volatility, impulsive behavior, chronic disorganization, and sleep issues. Recognizing these signs is crucial as, once identified, they can be properly examined and appropriately treated.

If you or someone you know exhibits signs like the ones described above, there is a high chance that it could be due to ADHD. Consult an expert in that case. There certainly are ways ADHD can be dealt with very effectively.

Perhaps, noticing these signs and seeking the care they need could actually just help someone turn their life around!

References

• Brunkhorst-Kanaan, N., Libutzki, B., Reif, A., Larsson, H., McNeill, R. V., & Kittel-Schneider, S. (2021). ADHD and accidents over the life span–A systematic review. Neuroscience & biobehavioral reviews, 125, 582-591.
• Dobrosavljevic, M., Larsson, H., & Cortese, S. (2023). The diagnosis and treatment of attention‑deficit hyperactivity disorder (ADHD) in older adults: A review. Expert Review of Neurotherapeutics, 23(10), 883–893. https://doi.org/10.1080/14737175.2023.2250913
• Kosheleff, A. R., Mason, O., Rubin, J., et al. (2023). Functional impairments associated with ADHD in adulthood and the impact of pharmacological treatment. Journal of Attention Disorders. https://doi.org/10.1177/10870547231158572
• Lovett, B. J., & Harrison, A. G. (2021). Assessing adult ADHD: The role of symptom and performance validity testing. The Clinical Neuropsychologist, 35(5), 1009–1033. https://doi.org/10.1080/13803395.2021.1950640
• Petrovic, P., & Castellanos, F. X. (2016). Top-down dysregulation—from ADHD to emotional instability. Frontiers in behavioral neuroscience, 10, 70.
• Rauf, M. A., Khan, J., Malik, M. A., et al. (2024). Attention Deficit Hyperactivity Disorder (ADHD)—Causes and Diagnosis in Adults: A Review. Cureus, 16(4). https://www.cureus.com/articles/179760
• Sadeghi-Bazargani, H., Hasanzadeh, K., Salarilak, S., Amiri, S., Golestani, M., & Shahedifar, N. (2019). Evaluating the relationship between adult attention-deficit/hyperactivity disorder and riding behavior of motorcyclists. Journal of Injury and Violence Research, 11(1), 45.
• Sörös, P., Hoxhaj, E., Borel, P., Sadohara, C., Feige, B., Matthies, S., … & Philipsen, A. (2019). Hyperactivity/restlessness is associated with increased functional connectivity in adults with ADHD: a dimensional analysis of resting state fMRI. BMC psychiatry, 19, 1-11.
• Thapar, A., Cooper, M., & Rutter, M. (2017). Neurodevelopmental disorders. European Child & Adolescent Psychiatry, 28(5), 519–522. https://doi.org/10.1007/s00787-019-01298-5
• Voinescu, B. I., Szentagotai, A., & David, D. (2012). Sleep disturbance, circadian preference and symptoms of adult attention deficit hyperactivity disorder (ADHD). Journal of neural transmission, 119, 1195-1204.