It may not seem unusual that people with short attention spans, who are easily distracted and who often act without thinking through the consequences, might be more accident-prone than the rest of us. But what is surprising is how often these accidents prove to be fatal.
According to a study published today in The Lancet, people with ADHD have a lower life expectancy than the general population, and are twice as likely to die prematurely - usually because they've been in some kind of an accident. This still only amounts to a three in 1,000 chance of an individual with ADHD dying early, but researchers say their findings are the first to show an association between the disorder and increased mortality.
The study examined the medical records of 1.92 million people born in Denmark between 1981 and 2011, including more than 32,000 people with clinically diagnosed ADHD.
Over the course of the 32-year follow-up, 107 people from the sample with ADHD died. The researchers assessed the causes of premature death in order to compare individuals with and without ADHD. After adjusting for a range of factors known to affect the risk of early mortality, such as drug use, other psychiatric conditions, and family history, they found that people with ADHD were twice as likely to die early.
Interestingly, women with ADHD were more likely to die prematurely than men with ADHD, and nearly three times as likely to die before healthy women. The researchers suggest this might be due to the fact that women are usually under-diagnosed and less likely to take prescription medicines.
The age of diagnosis also plays a significant role in mortality rates. Adults diagnosed at age 18 or older were four times more likely to die earlier than healthy peers. They also "had a greater risk of death than did those diagnosed in childhood and adolescence," the researchers noted in their study. "This finding could be caused by persistent ADHD being a more severe form of the disorder."
The researchers also found that risks of premature death went up when people with ADHD suffered from co-existing disorders, such as substance abuse disorder, defiant disorder and conduct disorder. If an individual had all four together they were eight times more likely to die prematurely.
"Our findings emphasise the importance diagnosing ADHD early, especially in girls and women, and treating any co-existing antisocial and substance use disorders," said lead author Soren Dalsgaard from Aarhus University in Denmark in a press statement.
"It is however important to emphasise that although the relative risk of premature death is increased in ADHD, the absolute risk is low."
The Danish group has previously shown that children with ADHD are at increased risk of sustaining injuries, while other studies have shown that people with ADHD anticipate less severe results from their risk-taking behaviour, and are less adept at preventing injuries to themselves.
Source: New York Times