Most kids with ADHD tend to show fewer symptoms of the disorder as they move through late adolescence to young adulthood. The hyperactivity that makes an 8-year-old unable to stay in his seat has subsided. A good many kids who were diagnosed with the combined type of the disorder—hyperactivity and impulsivity as well as inattention—no longer fit the symptom profile by college age.
That’s the good news, and the pattern holds for girls as well as boys. But a new study at UC Berkeley finds that there are other disturbing effects of ADHD in girls that may outlast the obvious symptoms of the disorder itself. A group of girls from age 17 to 24 who have a history of ADHD were found to have significantly higher rates of self-harm and suicide attempts than a comparison group.
The study evaluated a diverse group of 140 girls three times over 10 years. At the 10-year mark, girls with an ADHD diagnosis at the outset were twice as likely to report self-harming behaviors like cutting, and three times as likely to have made a serious suicide attempt.
There were also significant differences between girls in the two subtypes of ADHD—the combined type and those who are inattentive but not hyperactive. Among girls who had been diagnosed with combined-type 10 years earlier, 22% had made a serious suicide attempt. Of those with inattentive-type ADHD, 8% had made an attempt, and of girls in the comparison group, 6%.
In terms of self-injury, 51% of girls with combined-type ADHD reported cutting or some other moderate-to-severe form of self-injury, compared to 29% of ADHD inattentive-type and 19% of the comparison group.
“What we’re seeing is a huge rate of suicide attempts and self-injury for girls with ADHD combined-type,” notes lead author of the study Stephen Hinshaw, PhD, a UC Berkeley professor of psychology, despite the fact that 40% of these girls no longer present as combined-type. If you didn’t know their history, Dr. Hinshaw notes, you would probably not recognize the underlying impulsivity and mental restlessness they’re still experiencing.
Why would we see such elevated rates of self-injury and suicide attempts in a population that’s ostensibly doing better? “The lack of social and academic skills—the cumulative effect of what they missed when they were younger—take a toll,” says Dr. Hinshaw, who is also co-chair of the Child Mind Institute Scientific Research Council. And at the 5-year mark in the study it was already evident that this group had developed higher rates of “internalizing behaviors” like anxiety and depression than the comparison group, he adds, as well as “externalizing” behaviors like acting up and getting into trouble.
The combination of depression and impulsivity is what creates the highest risk for suicide, Dr. Hinshaw notes. “Impulsivity isn’t just blurting out things in class, it’s an inability to regulate emotion. Think of it as distress intolerance: the feeling that I can’t tolerate this pain another day, an inability to imagine that things might be different.”
The study also looked at eating disorders, finding that girls with a history of ADHD were not, at the 10-year mark, more likely to report symptoms of bingeing or purging. But that’s not because they were reporting less of this behavior. At the 5-year mark, girls with combined-type ADHD were twice as likely to report bingeing or purging than the comparison group, with girls with inattentive-type ADHD falling in between. What changed is that by the early adult years, the comparison group had caught up, Dr. Hinshaw explains.
“The overarching conclusion is that ADHD in girls portends continuing problems though early adulthood,” Dr. Hinshaw writes in the report. While many girls in the study showed improvements in ADHD symptoms during the 10-year period, some problems persisted and new ones emerged, making long-term monitoring and treatment essential.