MONDAY, March 4, 2013 — It turns out kids may not outgrow it — at least not when "it" is ADHD, according to a new study. And study participants who suffered from ADHD were more likely as adults to face a variety of other psychiatric disorders, from anxiety to depression.

Twenty-nine percent of children with ADHD maintained the disorder into adulthood, according to the study, published online today in Pediatrics. The study is the first of its kind to track a large sample of children with ADHD into later life. "We suffer from the misconception that ADHD is just an annoying childhood disorder that's overtreated," said William Barbaresi, MD, lead study investigator in a press release. "This couldn't be further from the truth. We need to have a chronic disease approach to ADHD as we do for diabetes. The system of care has to be designed for the long haul."

Researchers at Boston Children's Hospital and the Mayo Clinic tracked more than 5,700 children born from 1976 to 1982 in Rochester, Minnesota, including 367 diagnosed with ADHD. They were able to determine the adult health status of 232 of those who had been diagnosed with ADHD as children and found that:

29 percent still had ADHD as adults

81 percent of those who still had ADHD as adults also another psychiatric disorder, compared to just 35 percent of the adults who didn't have ADHD as children

2.7 percent with ADHD as adults were in jail when "recruited" for the followup study

.8 percent of those with ADHD as children committed suicide at some point before the study was completed, compared to .1 percent of those who didn't have ADHD as children.

"Only 37.5 percent of the children we contacted as adults were free of these really worrisome outcomes," added Dr. Barbaresi. "That's a sobering statistic that speaks to the need to greatly improve the long-term treatment of children with ADHD and provide a mechanism for treating them as adults."

According to the U.S. Centers for Disease Control and Prevention, ADHD is the most common neurobehavioral disorder affecting children. Moreover, the American Psychiatric Association reports that 3 to 7 percent of U.S. school-aged kids has ADHD.

This study, however, may suffer from bias since subjects were of middle class and well-educated backgrounds with access to sufficient health care, assert researchers. "One can argue that this is potentially a best-case scenario," Barbaresi said. "Outcomes could be worse in socioeconomically challenged populations."

Either way, Barbaresi stresses the importance of quality ADHD treatment that not only lasts throughout adolescence but also accounts for the prevalence of learning disabilities and other mental health conditions. Additionally, he notes the viability of ADHD medications for adults — prescribed mainly to children — though many adults go untreated and don't even known they have ADHD.