GROWING UP WITH ADHD A 40-year study follows untreated children into adulthood.

The importance of adequately treating ADHD in young people was underscored by a four-decade study, the longest of its kind, published in the Archives of General Psychiatry in 2012. Researchers led by Rachel Klein, PhD - followed a group of 135 white, middle- class males with combined-type ADHD from childhood into adulthood. The children were free of conduct problems, such as aggression, taunting, lying, and having general disregard for rules. None of the subjects were on stimulant medication after age 13, due to a belief (since discredited) that adolescents would become addicted to such drugs. In fact, few received any kind of ongoing therapy for the disorder.

The study began in 1970, when the subjects’ mean age was 8, and the researchers checked on them in late adolescence and adulthood. Conduct problems began cropping up when the boys were in their teens. By 2011, when they had reached an average age of 41, they showed significantly worse educational, occupational, economic, and social outcomes, compared to 136 controls without ADHD who came from similar backgrounds.

Only 16 percent finished college, versus 35 percent of the controls. The ADHD group earned far lower incomes: a median of $52,000, compared to $96,000 for the controls. A third of the men with ADHD were divorced, versus a tenth of the controls. Almost three times as many (14 percent versus 5 percent) had a substance-abuse disorder. Fully three times as many (36 percent versus 12 percent) had been incarcerated.

Surprisingly, the disorder was diagnosed in adulthood in only 22 percent of the ADHD group. Nonetheless, many continued to suffer the consequences of poor choices they had made years earlier. “Their disadvantages originated in adolescence,” Dr. Klein says. “Ordinary teenagers engage in impulsive behaviors, but these kids did so even more, and with greater variety and severity. Some were jailed multiple times and a substantial proportion continued as adults to engage in antisocial behavior. This pattern of chronic antisocial maladjustment was unique to the ADHD group. They couldn’t follow the rules even if they wanted to.”