Researchers are just beginning to study and predict the impact of childhood variables on the risk of developing adult ADHD. According to one study, the four most powerful positive variables predicting a good outcome for children include being raised in an intact household above the poverty level, by parents who don't have psychiatric problems, with a consistent parenting style, and by parents who are emotionally and physically available to their children.

Studies also show that aggressive behavior, depression, and substance abuse on the part of parents may increase their children's risk of adult ADHD. Other variables likely to increase the risks include parental psychopathy, learning disabilities, and lower intellect.

Research also shows that children and teenagers raised in poverty have a higher chance of having parents who are either unemployed or underemployed, lack health insurance, and do not schedule regular medical checkups for either their children or themselves. If one or both parents has adult ADHD, the chances are even higher that a child will be brought up in poverty because his parent(s) may be unable to get or keep jobs, are at a higher risk of getting divorced, and are also more likely to be arrested and jailed.