The research was conducted by experts from Boston Children's Hospital and the Mayo Clinic, and was published in the journal Pediatrics.
Children with ADHD also have a higher probability of committing suicide and being put in prison as adults, according to the authors.
William Barbaresi, M.D., lead researcher from Boston Children's Hospital who started the report when he was at the Mayo Clinic, said:
"Only 37.5 percent of the children we contacted as adults were free of these really worrisome outcomes. 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."
This is the first large, population-based study to follow kids with ADHD into adulthood, which is what makes it unique, explained Slavica Katusic, M.D., an epidemiologist and Mayo Clinic's lead investigator on the research.
ADHD is the most prevalent neuro-developmental disorder among children. Approximately 7% of all kids, and three times as many boys as girls, are affected by the disorder.
Most previous follow-up reports of ADHD have been small and centered on more serious cases, for example, boys taken to pediatric psychiatric treatment facilities, as opposed to a cross-section of both males and females with ADHD.
The current study followed all kids born in Rochester between 1976 and 1982 who were still living in the same place at age 5 and whose families permitted access to their medical records.
A total of 5,718 children were included in the investigation - 367 were diagnosed with ADHD. Of this group, 232 were involved in the follow-up report. An estimated 75% were treated for ADHD as kids.
Results showed that 29% of children with ADHD still had the disorder in adulthood.
Fifty-seven percent of kids with ADHD had at least one other psychiatric disorder as adults, versus 35% of those who did never had ADHD as a child.
The most common psychiatric disorders identified included:
- major depression
- generalized anxiety
- antisocial personality disorder
- hypomanic episodes
- substance abuse/dependence
Seven of the 367 kids who had ADHD (1.9%) had died by the time the investigation started. Three of them had committed suicide.
Of the 4,946 boys and girls not affected by ADHD whose outcomes could be discovered, 37 died. Five of them committed suicide.
This suggests that mortality due to suicide was almost 5 times greater among childhood ADHD cases as opposed to the controls from the same age group, the authors said.
A report from 2010 indicated that kids with ADHD are more likely to develop depression and/or attempt suicide during their adolescent years, or 5 to 13 years after diagnosis.
Ten adults who had ADHD when they were young (2.7%) had been put in jail when the research began.
A prior study from 2012 demonstrated that people with ADHD have a significantly lower chance of engaging in criminal behavior when they are taking medication.
Dr. Barbaresi explained:
"We suffer from the misconception that ADHD is just an annoying childhood disorder that's overtreated. 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."
It is possible that the results of the study underestimate the negative consequences of childhood ADHD, according to Dr. Barbaresi. The majority of those analyzed where white and middle class, with good education and able to obtain health care.
"One can argue that this is potentially a best-case scenario," Dr. Barbaresi pointed out. "Outcomes could be worse in socioeconomically challenged populations."
He suggests that parents of kids with ADHD make sure that their children are receiving high-quality treatment and continue receiving treatment into their teenage years.
Children should be evaluated for learning disabilities and observed for conditions linked to ADHD, such as:
- substance use