The onset of attention deficit hyperactivity disorder (ADHD) probably only occurs during childhood, and not during adulthood, according to new research.
In a study published last month in the American Journal of Psychiatry, researchers say most people who are diagnosed with adult-onset ADHD probably don’t have the disorder.
Researchers say the symptoms used to diagnose adult-onset ADHD tend to be more indicative of other factors, such as psychological trauma, drug use, or depression.
Others who’d been diagnosed with adult-onset ADHD likely had childhood ADHD that had gone undiagnosed.
The lead author of the study told Healthline that, while adults can have ADHD, it’s unlikely that the disorder develops during adulthood.
“Most people with ADHD in adulthood probably always had it as a kid,” said Dr. Margaret Sibley, a clinical psychologist and researcher at the Florida International University Herbert Wertheim College of Medicine and Center for Children and Families. “That’s different from [ADHD symptoms] suddenly coming out of nowhere.”
Gaining a nuanced understanding
Sibley explained what led her and her colleagues to take a closer look at adult-onset ADHD diagnoses.
“About two years ago, there was a study published by a group in New Zealand that had a big epidemiological sample of people who had been followed up from birth to adulthood. The study suggested that a really large portion of the population, around 5 percent, had something called adult-onset ADHD, which would be having the adult symptoms of ADHD without ever having had a trace of it in childhood or adolescence — basically, spontaneously developing ADHD as an adult.”
While many in the health community were surprised by these findings, several other groups bolstered the findings with supporting research of their own.
“I personally went to some different scientific meetings and saw the authors of these papers present, and a lot of psychiatrists and practitioners who were in the audience would get up and challenge their findings, asking, ‘Did you realize there are other reasons that people would say yes on a checklist of ADHD symptoms? Things like having a substance abuse problem, or having depression or a concussion — were you thinking of that in your research?’” Sibley explained.
“Essentially, the answer was, ‘No, we didn’t have the ability to look at that, all we can look at is whether people say yes or no on these checklists.’ So in the audience, I was thinking to myself that I work with a group that has the data to look at that, and may be able to see if people say yes to ADHD checklists because of real ADHD symptoms, or if other things could be leading them to do so.”
Sibley and her colleagues studied a group of 239 participants, starting around age 10 and ending around age 25. Looking beyond the answers on an ADHD checklist, the researchers examined the context of this reporting.
While some people are correctly diagnosed with ADHD in adulthood because the diagnosis was missed during childhood, the research team focused on those whose adult-onset ADHD diagnosis could be explained by other factors.
Going beyond the checklist
“A lot of the symptoms of ADHD are somewhat suggestive,” said Sibley. “So people tend to say yes to them even if they don’t necessarily have the symptoms.”
As an example, a clinician may ask a patient if they have trouble concentrating — an issue that almost everybody experiences from time to time.
Another issue is that ADHD symptoms can often be attributed to factors beyond the disorder.
“Symptoms of concentration and difficulty focusing can also be explained by a lot of other things,” said Sibley. “They look a lot like the symptoms of having a concussion, or the symptoms of chronic marijuana use, or having depression and apathy. So if someone’s not taking a really close look and thinking of what causes these symptoms, it’s easy to say, ‘Oh yeah, looks like ADHD.’”
To move toward more accurate diagnoses, Sibley said clinicians could corroborate self-reported symptoms with the reports of other people in the patient’s life.
“You can look at objective things — has this person had trouble in school, or do they have trouble keeping a job? Things like that could give you an indication that the person’s struggling in some way, going beyond filling out a quick checklist of symptoms.”
Future research could include more insights into how other factors — such as trauma, daily stress, brain injuries, or other illnesses — could lead to false diagnoses of ADHD.
Until then, Sibley said, it’s important to take a nuanced look at each patient.
“The big message is to be really careful, and look a little bit deeper at what’s going on for people,” she said.