Jan. 8, 2004 -- When it comes to attention deficit hyperactivity disorder, the apple doesn't fall far from the tree. More than 20 studies already confirm that ADHD can be inherited, affecting parent, child, and even cousins and other extended family members.
But a new study indicates just how strong the family tradition may be and could help explain -- and predict -- other mental health and behavior problems affecting families.
Researchers find that parents of children with ADHD -- and in particular, mothers -- are 24 times more likely to have the condition themselves compared with parents whose kids don't have the disorder. What's more, when the ADHD child is also defiant, oppositional, or has serious conduct problems, their parents are up to five times more prone to other behavior and mood problems compared with adults whose kids haven't been diagnosed with ADHD.
"We weren't really surprised by the strong family tendency of ADHD, but what we thought was really interesting was the high rates of other disorders among parents of young children with ADHD," says lead researcher and psychologist Andrea Chronis, PhD, director of the University of Maryland ADHD Program.
"When a child has pure ADHD, the only thing the parents are more prone to is ADHD," she tells WebMD. "But when the child also has conduct or oppositional disorders, you really see a strong pattern of past and current mood disorders, anxiety, substance abuse, depression, and other problems in their parents."
Her study, published in the December 2003 issue of the Journal of the American Academy of Child and Adolescent Psychiatry, is the latest venture in a 10-year research project tracking the development of 98 children diagnosed with ADHD during preschool and comparing it with 116 non-ADHD kids. But by now looking into the parents' histories, Chronis says she hopes her research may help lead to better understanding -- and prediction -- of continued patterns of ADHD symptoms in family members, as well as future depression and other mental health issues.
"Based on our research, it's clear we need to treat the whole family, not just the child. Too often the answer is to give the children drugs. When there are problems in the family, you need to address those, too."
Although it's now estimated that about one in 20 American adults has ADHD, researchers believe that only 15% to 25% of them know it. That's because ADHD has long been considered a childhood problem that can be "outgrown." Only in the past year or so has awareness increased that ADHD also affects adults, largely because of the marketing efforts of Strattera, the first drug approved by the FDA to treat adult ADHD.
"Back when I was trained as a psychologist, we were taught that you outgrew ADHD and it didn't affect adults," says clinical psychologist Michele Novotni, PhD, president of the Attention Deficit Disorder Association and author of one of the first books on adult ADD. "Unfortunately, that's why it wasn't diagnosed in adults."
Instead, these patients stumbled through life -- considered to be lazy or stupid when, in fact, they had a medical condition that could be effectively treated with drugs and therapy. They may have depression and other conditions not associated with ADHD.
Novotni isn't surprised by Chronis' findings because she says she knows firsthand of the genetic tendency of ADHD. Her father was diagnosed when he was age 65 - only after her son was diagnosed with the condition at age 2. Other afflicted family members include Novotni's sister and several nephews.
"My father was incredibly brilliant but had flunked out of college a number of times and got fired several times from his job as an inventor because he wouldn't follow through or did follow through but forgot were he put the papers," she tells WebMD. "We didn't know why my father had never worked up to his potential. No one did."
In fact, her association has been developing a campaign to alert doctors who are treating ADHD children, seeking that they also inquire about their parents' mood and behavior. "Once a child is identified with ADHD, it's a good bet that parents are also somehow afflicted but may not have been diagnosed."
Clues may include a tendency to lack focus -- especially in mundane activities -- or a tendency toward moodiness, impulsiveness, or recklessness. One of Novotni's clients was diagnosed with ADHD only after he went shopping for balloons one day and put in a bid for house he drove by. "And he wasn't house shopping," she says.