ADHD is not just a childhood disorder that resolves spontaneously after adolescence. The symptoms often persist into adulthood. As ADHD is a developmental disorder, it's believed it cannot develop in adults without it first appearing during childhood.
The prevalence of ADHD in adults is 4.4% worldwide.
In some clinical series, the ratio of men to women with ADHD is close to 1:1.
Long-term follow-up studies revealed that in 40 to 60% of children with ADHD, the disorder persists into adulthood.
In adults, the symptoms of ADHD are more difficult to define.
By the age of 25, an estimated 15% of people diagnosed with ADHD as children still have a full range of symptoms, and 65% still have some symptoms that affect their daily lives.
But some specialists say the way in which inattentiveness, hyperactivity, and impulsiveness affect adults can be very different from the way they affect children. For example, hyperactivity tends to decrease in adults, while inattentiveness tends to get worse as the pressures of adult life increase.
Adults with ADHD experience difficulties in all aspects related to employment, from the initial job search to the interview and performance on the job itself. Patients complain consistently about mood swings, difficulties in dealing with stressful situations, frequent irritability and frustration, emotional excitability, and getting angry over minor things.
Moreover, adults with ADHD often present with concurrent psychiatric disorders, to the extent that up to two-thirds of adults with ADHD show at least one comorbid psychiatric condition (this phenomenon has been described in several studies, which indicated comorbidity rates between 57% and 92%).
ADHD symptoms in adults may present differently than in younger ages, as impulsivity, hyperactivity, and inattention are generally expressed in more subtle and diverse ways. Patients may complain of inner restlessness, talkativeness, excessive fidgeting also in situations where one is expected to sit still as in meetings, lectures, or at the movies. This may be an expression of hyperactivity. Impulsivity may express itself as impatience, 'acting without thinking', incapability of holding a job or maintaining personal relationships or any type of attention-seeking behavior. Other complaints, such as feeling bored, unable to make decisions, procrastinating, being disorganized, and distracted may constitute an expression of inattentiveness.
Out of the three subtypes of ADHD, the inattentive type was found to be the most prevalent among adults (47%-90% of cases).
Some specialists have suggested the following as a list of symptoms associated with ADHD in adults:
• carelessness and lack of attention to detail;
• continually starting new tasks before finishing old ones;
• poor organizational skills;
• inability to focus or prioritize;
• continually losing or misplacing things;
• restlessness and edginess;
• difficulty keeping quiet, and speaking out of turn;
• blurting out responses and often interrupting others;
• mood swings, irritability, and a quick temper;
• inability to deal with stress;
• extreme impatience;
• taking risks in activities, often with little or no regard for personal safety or the safety of others – for example, driving dangerously. Zalsman, G., & Shilton, T. (2016). Adult ADHD: A new disease? International Journal of Psychiatry in Clinical Practice, 20(2), 70–76.
Tucha, O. (2017). Supporting patients with ADHD: Missed opportunities? ADHD Attention Deficit and Hyperactivity Disorders, 9(2), 69–71.
V.Salvi et al. (2019) ADHD in adults: clinical subtypes and associated characteristics. doi: 10.1708/3142.31249.
Scrandis, D. A. (2018). Diagnosing and treating ADHD in adults. The Nurse Practitioner, 43(1), 8–10.
Volkow, N. D., & Swanson, J. M. (2013). Adult Attention Deficit–Hyperactivity Disorder. New England Journal of Medicine, 369(20), 1935–1944.