NEW YORK (Reuters Health) - Nearly a third of people diagnosed as children with attention deficit hyperactivity disorder (ADHD) still have the condition in adulthood, according to a large new study that also found they're more likely to develop other mental disorders and to commit suicide.
U.S. researchers who published their findings in Pediatrics on Monday found that about 29 percent of participants in the study who were diagnosed with ADHD as children ended up carrying that diagnosis into their late twenties.
"They still clearly had symptoms that continued to be consistent with that diagnosis. But that in itself has been an area of difficulty and controversy," said the study's lead author, Dr. William Barbaresi, from Boston Children's Hospital.
ADHD, which is the most common neuro-developmental condition, affects between 3 percent and 7 percent of American school children, according to the U.S. Centers for Disease Control and Prevention (CDC). It's more common in boys than girls.
The CDC says kids with ADHD tend to have a hard time paying attention, to be forgetful, fidget and be easily distracted, to the point that it creates problems at school, at home and with their friends.
Until now, most studies looking at ADHD in children and adults used data that's known to be unreliable, or information from people with severe forms of the disorder, according to the new report.
For their study - which Barbaresi started while at the Mayo Clinic in Rochester, Minnesota - the researchers followed 5,718 children who were born in that area between 1976 and 1982. Of those, 367 were diagnosed with ADHD as children and gave the researchers access to their medical records.
Barbaresi and his colleagues then invited the participants to be reevaluated when they were about 29 years old.
Overall, 232 of the childhood ADHD patients agreed to be part of the study as adults, and the researchers found that 68 still had the disorder - about 29 percent.
But even those participants whose ADHD diagnosis did not persist into adulthood were still more likely to suffer from at least one psychiatric condition other than ADHD.
The researchers found that 57 percent of childhood ADHD patients had at least one psychiatric condition as adults - most commonly alcohol or substance abuse, anxiety and depression - compared to 35 percent of the people in a comparison group who did not have ADHD while growing up.
People diagnosed with ADHD as children were also more likely to commit suicide by the time of the follow-up study.
The researchers found that 3 of the 367 participants with childhood ADHD had committed suicide, compared to just 7 of 4,946 non-ADHD participants.
"The finding about suicide is new. It was suggested in another one of these longitudinal studies, but in this study the sample size was large enough for it to be significant," said Mary Solanto, director of the ADHD Center at the Icahn School of Medicine at Mount Sinai in New York.
Solanto, who was not involved in the new research, said many of the study's other findings have been seen in previous studies. "What's new is that this is larger and the subjects were drawn from the general population," she added.
The study's authors caution, however, that their findings may not apply to children across the U.S., because their study participants were from mostly white, middle-class families in one area of Minnesota.
"It is possible, if not likely, that the magnitude of the adverse outcomes … would be even greater in populations with additional challenges such as higher rates of poverty," they write.
Barbaresi told Reuters Health that this study is a "high-level" view of some of the most serious outcomes. He said additional studies with more results will be published later.
But despite these findings, Solanto said ADHD does not have to be a barrier to success.
"There are a lot of people who have had it that learned to cope and deal with it. But in order for that to happen, it's important to diagnose and treat it as soon as possible," she said.
"The focus needs to be on this condition, because it a serious health problem and we're not treating this way," Barbaresi said.
SOURCE: http://bit.ly/HjQ8dI Pediatrics, online March 4, 2013.