ADHD might help you live longer.

From http://healthland.time.com/2013/01/11/could-a-dopamine-gene-be-the-answer-to-a-longer-life/#ixzz2I1ZB0i00

A study published in the Journal of Neuroscience found that a version of a gene coding for a receptor for the brain chemical dopamine was 66% more common among people who lived to be 90 or older than among a group of younger people who were otherwise similar.
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When dopamine isn’t regulated properly, it can contribute to a dysfunctional pursuit of good feelings, such as occurs in addictions, or lead to a hyperactive state as in attention deficit/hyperactivity disorder (ADHD). These conditions are generally associated with an increased risk of early death, rather than longevity, but the latest study suggests that “risk” genes for certain problems in some environments may be beneficial in other situations. It’s not helpful to think of genes as “good” or “bad,” in other words, but instead to consider them as more dynamic.

The dopamine variant may be a good example. This gene has been connected to ADHD, which in turn is linked to a 50% increase in the risk of car accidents, for example, as well as similar increases in other risk-taking behaviors that can lead to accidental injury and early death. Studies have also correlated the variant to heightened promiscuity and infidelity, which carry a higher incidence of sexually-transmitted disease.

But if people with this genetic variant make it past the risky years of adolescence and early adulthood, then the positive benefits of being physically active throughout their lifetime may give them some extra years. People with ADHD, for example, are often unable to sit still, and the constant fidgeting and activity may end up having a net positive effect on their ability to avoid chronic diseases associated with being sedentary. Even thrill-seeking behavior often requires physical exertion, so those who survive the potentially dangerous activities of their youth may actually live longer than those who weren’t always in pursuit of the next high.