ADHD in adulthood?

Attention deficit hyperactivity disorder (ADHD), usually diagnosed in children, may show up for the first time in adulthood, two recent studies suggest.

And not only can ADHD appear for the first time after childhood, but the symptoms for adult-onset ADHD may be different from symptoms experienced by kids, the researchers found.

“Although the nature of symptoms differs somewhat between children and adults, all age groups show impairments in multiple domains – school, family and friendships for kids and school, occupation, marriage and driving for adults,” said Stephen Faraone, a psychiatry researcher at SUNY Upstate Medical University in Syracuse, New York and author of an editorial accompanying the two studies in JAMA Psychiatry.

Faraone cautions, however, that some newly diagnosed adults might have had undetected ADHD as children. Support from parents and teachers or high intelligence, for example, might prevent ADHD symptoms from emerging earlier in life.

It’s not clear whether study participants “were completely free of psychopathology prior to adulthood,” Faraone said in an email.

One of the studies, from Brazil, tracked more than 5,200 people born in 1993 until they were 18 or 19 years old.

At age 11, 393 kids, or 8.9 percent, had childhood ADHD. By the end of the study, 492 participants, or 12.2 percent, met all the criteria for young adult ADHD except the age of diagnosis.

Childhood ADHD was more prevalent among males, while adult ADHD was more prevalent among females, the study also found.

Just 60 of the nearly 400 kids with ADHD still had symptoms at the end of the study, and only 60 of the nearly 500 adults with ADHD had been diagnosed as children.