Missing a diagnosis of attention deficit hyperactivity disorder in adulthood means that patients also miss out on effective treatment which is often life-changing Image by ytemha34
Missing a diagnosis of attention deficit hyperactivity disorder in adulthood means that patients also miss out on effective treatment, which is often life-changing. Image by ytemha34

Calling attention to adult ADHD

Missing an adult diagnosis of attention deficit hyperactivity disorder (ADHD) means patients also miss out on effective, often life-changing treatment.

Attention deficit hyperactivity disorder (ADHD), often considered a disorder of childhood, may not be top of mind for most internal medicine physicians.

However, the estimated prevalence of adult ADHD was 4.4% in a study of about 3,200 U.S. young adults ages 18 to 44 years, according to results published in 2006 by the American Journal of Psychiatry. Among older adults ages 60 years and older in The Netherlands, another study estimated a 2.8% prevalence rate, according to results published in October 2012 by the British Journal of Psychiatry.

While those prevalence rates are comparable to those of generalized anxiety disorder (3%) and bipolar disorder (2%), studies suggest that 75% of adults with ADHD have never been diagnosed, said David W. Goodman, MD, an assistant professor of psychiatry and behavioral sciences at Johns Hopkins University School of Medicine in Baltimore.

“And some of the studies, although small and the quality is questionable, do indicate that 100% of those over the age of 50 were never diagnosed,” he said.

History partly explains why more older adults aren't diagnosed with ADHD, Dr. Goodman said. “In the '50s and '60s, ADHD really was reserved for the most disruptive and problematic boys, so that's not surprising,” he said. “But this idea that if you weren't diagnosed before, you can't have ADHD as an adult, that's just incorrect.”

Missing the diagnosis means that patients also miss out on effective treatment with first-line stimulant medications, said Dr. Goodman. “Stimulant medications are some of the most effective medications in all of psychiatry, with effect sizes of 1.0, whereas antidepressants, for example, have an effect size of 0.35,” he said.

Dr. Goodman has diagnosed patients with ADHD later in life, in their 50s, 60s, and 70s, and said treatment is often life-changing, with patients reporting improved functioning, interpersonal relationships, and overall quality of life.

“It's not that hard to do; you just have to know what ADHD looks like, and more importantly, you have to believe in the validity of this diagnosis,” he said. “We've got over 30 years of scanning research that shows ADHD brains are just wired differently.”

Experts explained the steps needed to diagnose ADHD and outlined treatment considerations, including the cardiovascular risks of stimulants to treat ADHD in older adults.

Making the diagnosis

Typically, a psychiatrist or other mental health expert makes the diagnosis first, Dr. Goodman said. “And then once the diagnosis is made, the treatment is instituted, and the patient is stable, then the internists in primary care are comfortable prescribing ongoing medication.”

However, with increasing public awareness of ADHD and an ongoing shortage of mental health clinicians, there has been a push to get primary care and internal medicine physicians more involved, he said.

“They can make a diagnosis if they are aware of the series of questions to ask … and then we try to get collateral information from a spouse, a mother, a sibling who has a history with the person who can say, ‘Yeah, this has been going on for as long as we all can remember,’” Dr. Goodman said.

Even if it doesn't seem like it, ADHD is already part of your primary care practice, said Stephanie Collier, MD, MPH, the director of education in the division of geriatric psychiatry at McLean Hospital and an instructor in psychiatry at Harvard Medical School in Boston.

“For all primary care doctors, this is a part of their practice,” she said. “The patients will show up at their offices, whether they think about ADHD or not.”

A common screening tool in primary care settings is the Adult ADHD Self-Report Scale (ASRS), a frequency-based checklist consisting of the 18 symptoms in the DSM-5 criteria for ADHD: nine symptoms of inattention (e.g., troubles with listening, organization, distractions, and forgetfulness) and nine symptoms of hyperactivity and impulsivity (e.g., fidgeting, feeling restless, talking excessively).

“It's scored on a 0 to 4, and if the patient scores 3 and/or 4 for five of nine inattentive or five of nine hyperactive-impulsive, then there's a very, very high likelihood that the person has ADHD,” said Dr. Goodman.

Clinicians can consider screening for ADHD in patients who report cognitive changes, such as being more forgetful or inattentive, he said, offering the example of a 55-year-old man who reports misplacing his keys and wallet and whose spouse says the issue has gotten worse over the years.

“If you didn't know ADHD in the clinical presentation, you might easily say, ‘This is age-related cognitive decline. We'll send you for neurologic evaluation, maybe we'll send you for a head MRI,’ get the routine bloodwork, screen out any medical issues, and then just say, ‘Welcome to the 50s,’” Dr. Goodman said. “If you did a screening for ADHD, though, the prevalence rate for older adults is about 3%.”

But a positive screen alone is not enough to make a diagnosis. “Symptoms are really only one out of five criteria that have to be met to have a diagnosis of ADHD,” Dr. Collier said.

Symptoms must have started before age 12 years, she noted, adding that performance in school can also be a clue. “You need to have some impairment; it's a disabling condition. So if they were valedictorian, they probably did not have [previously undiagnosed] ADHD.”

Several symptoms must also be present in two or more settings, Dr. Collier said. “So even if [the patient] was having difficulty in school, it would also have to show up in work performance and relationships, multiple different domains.”

The symptoms must also impair functioning. “It's not just ‘Oh, I have trouble concentrating at work,’” she said. “It would be ‘I lost my job,’ or ‘I lost multiple jobs in a short amount of time.’”

Finally, the symptoms must not be better explained by another disorder, which can get tricky in older adults with comorbidities. “ADHD, first of all, is highly comorbid with other illnesses like depression or anxiety, but also problems concentrating can happen because of a neurocognitive disorder, medications, poor sleep, or medical conditions,” Dr. Collier said. “There are lots of other explanations why someone might have symptoms of ADHD.”

After a positive screen, she recommended that primary care doctors ask an open-ended question about when the symptoms first started. If symptoms did start in childhood, then follow up with additional questions, such as: Do you run red lights? Have you had car accidents? Have you had sexually transmitted infections? Have you been arrested? Have you lost jobs or been reprimanded at work? “Those are the questions that help tease out how severe this is and what domains it's impacting,” Dr. Collier said.

ADHD is also one of the most heritable disorders in medicine, she noted. “Often, older adults will come to their doctors saying their child or their grandchild has been diagnosed with ADHD. Could they be suffering from the same illness?” Dr. Collier said. “If there's a strong family history, so multiple first-degree relatives, then you start thinking, ‘This might be ADHD.’ If it's the only person in the family, then you think it's probably less likely.”

ADHD is both over- and underdiagnosed, depending on the patient population, Dr. Collier said.

“Overdiagnosis actually does happen in primary care where patients score positively on the ASRS, they get a stimulant trial, they say they do better, and now they have ADHD in their chart, even though it's not as impairing, or didn't start before age 12, or there's another explanation, like they're anxious,” she said.

As for underdiagnosis, ADHD often goes undetected in young girls, who might be quieter and not as disruptive as boys, as well as in older adults, she said.

“Older adults, they may have lived their whole life trying to compensate with a lot of structure, and they get through,” Dr. Collier said. “And then they retire, and they lose the structure, and it's really hard, and that's where the symptoms come out again.”

Treatment considerations

While there are U.S. guidelines for the diagnosis and treatment of ADHD in children and adolescents and international guidelines for diagnosing and treating adult ADHD, no U.S. guidelines for adult ADHD are in place, Dr. Goodman noted.

“However, with great optimism and fanfare, the American Professional Society for ADHD and Related Disorders, for which I'm on the executive committee, has put together a steering committee, and we intend to have guidelines published within the year,” he said.

Medications that are FDA indicated to treat ADHD fall into three buckets: amphetamine-based stimulants (e.g., Adderall, Vyvanse), methylphenidate-based stimulants (e.g., Ritalin, Concerta), and nonstimulants (atomoxetine, guanfacine, clonidine, and viloxazine), explained Kevin M. Simon, MD, an attending psychiatrist at Boston Children's Hospital and an instructor in psychiatry at Harvard Medical School in Boston.

In adults, the general recommendation is to start with a long-acting stimulant medication if the patient has ADHD and no absolute contraindications, experts agreed, as long-acting stimulants cause fewer “ups and downs” and have a lower risk of diversion compared with shorter-acting ones.

When choosing a stimulant, “There's no way of looking at the patient's symptom profile and saying they will respond better to a methylphenidate or an amphetamine,” Dr. Goodman said.

However, a meta-analysis of 133 trials (81 in children and adolescents, 51 in adults, and one in both) found that evidence of efficacy and safety supports methylphenidate in children and adolescents and amphetamines in adults as first-line medications, according to results published in August 2018 by The Lancet Psychiatry.

Since the trials generally don't include older populations, most of the long-acting stimulants have FDA approval up to age 65 years, and lisdexamfetamine has approval up to age 55 years, Dr. Goodman noted. “That doesn't necessarily mean you can't use medications off label, but well-controlled trials haven't been done in over-65s.”

Dr. Collier said she thinks of treating ADHD in older adults similarly to treating children and adolescents, where the first choice would not be an amphetamine-based stimulant. “In 18- to 50-something-year-olds, that would be your first-line, usually, because it's a little bit more potent. … But in older adults, you want to go gentle, generally with a [methylphenidate-based stimulant], unless they've had prior trials,” she said.

When prescribing a new stimulant for adult ADHD, blood pressure is the most important vital sign to monitor, said Dr. Simon, who is also the inaugural chief behavioral health officer for the City of Boston. That's because of the mechanism of action for stimulants, which increases norepinephrine and thus raises blood pressure, he noted.

To ensure the stimulant dose is appropriate, Dr. Simon recommended having the patient take a home blood pressure reading a couple of hours after they've taken the medication. “They mark that down for themselves, and they alert their subspecialist or primary care provider to what the systolic and diastolic numbers were, because you don't want someone to have an excessively high blood pressure for any reason,” he said.

A systematic review and meta-analysis of 19 studies found no statistically significant association between ADHD medications and risk of cardiovascular disease, according to results published in November 2022 by JAMA Network Open. However, despite a wide confidence interval, there was a potential signal of increased risk in older adults compared with young and middle-aged adults (pooled adjusted relative risk, 1.59 vs. 1.04), noted cardiologist Roy C. Ziegelstein, MD, MACP, the Sarah Miller Coulson and Frank L. Coulson Jr. Professor of Medicine and vice dean for education at Johns Hopkins University School of Medicine in Baltimore, in an accompanying editorial.

“My commentary was just to put a cautionary note that the data among older individuals, and in particular older individuals with established cardiovascular disease, is not robust enough to draw conclusions,” he said.

When considering ADHD treatment with a stimulant in older adults, be careful about interactions with other medications that affect the heart, such as serotonergic medications, and other illnesses where blood pressures are not stable, such as dysautonomia in Parkinson's disease, Dr. Collier said. “And if I have any questions, I would consult with a cardiologist just to make sure.”

Another study of older adults found that prescription stimulant use was associated with a 40% increase in cardiovascular events within the first 30 days, but the risk decreased after that, according to results published in October 2021 by JAMA Network Open. “It was not a perfect study, and there was a selection bias … but we can feel a tad more reassured with this study that the main risks all happened in the first 30 days,” Dr. Collier said.

Ultimately, physicians should think carefully about the potential for benefit and harm of ADHD treatment in older adults before prescribing, Dr. Ziegelstein said.

“Every intervention, even taking daily aspirin, for example, has potential for benefit and potential for harm,” he said. “I think that prescribing ADHD meds to an older population, especially an older population with cardiovascular disease, requires very personal and very tailored-to-the-individual thought about potential for benefit and potential for harm.”

Psychotherapy and structure in one's daily routine, including reminders, organizational techniques, and auditory and visual cues, are also valuable treatments for ADHD, especially given ongoing shortages of ADHD medications, said Dr. Goodman. “All of that has to be instituted because if you don't have your medication for a day, a week, a month, hopefully you have the skills that you can fall back on,” he said.

Once a patient with ADHD is taking medication, symptoms tend to rapidly reduce, said Dr. Goodman. “They come back and see me in three weeks and say, ‘I had no idea, is this how the rest of the world functions?’” he said. “That gets a buy-in to the accuracy of the diagnosis.”

As symptoms reduce, daily functioning improves, self-confidence goes up, patients start taking on tasks they previously would have avoided, and others start to notice, Dr. Goodman said. “People around you notice that you're more dependable and more reliable,” he said. “When people at work notice you're more dependable and reliable, people start giving you more responsibility, your career advances, you manage to finish school: college, law school, med school, graduate school, MBAs.”

Two months into treatment that appears to be working, have the patient fill out the ASRS again to monitor progress, he suggested. “You'll notice that the frequency of these symptoms has significantly declined. They have to decline 50% or more to really have a daily functional effect.”

That upward trajectory, along with guided psychotherapy, can help the patient understand their condition. “The epiphany for people is when they finally realize that there's a difference between who they are and what they have,” he said. “And they are not their ADHD.”