It is a known fact that ADHD patients are more prone to problems with substance abuse and criminality. But now a group of researchers from the National Centre for Register-Based Research at Aarhus University have documented that ADHD is in fact associated with significantly increased mortality rates as well, and accidents have proven to be the leading cause of death.
This is the first study ever to shed light on the role of ADHD in premature death, and it is one of the most comprehensive and statistically significant studies to date. The large nationwide cohort study is based on unique Danish registry data, tracking a large sample of the Danish population over the course of 32 years: about 1.92m individuals of whom 32,061 were diagnosed with ADHD.
"During follow-up, we registered 107 deaths among the 32,061 ADHD patients – which may seem like very few. But the results are clear: the mortality rate is doubled in patients with ADHD," explains Dr Søren Dalsgaard, who is a medical specialist in child and adolescent psychiatry, consultant and senior researcher at the National Centre for Register-Based Research at the School of Business and Social Sciences, Aarhus University. He is the driving force behind the project, which he has carried out in collaboration with researchers from Aarhus University and Yale University in the US.
In their study, the researchers found that ADHD patients have an increased risk of dying prematurely due to both natural and unnatural causes, but the excess mortality was primarily driven by deaths from unnatural causes, most of which were due to accidents.
The fact that ADHD patients are more prone to accidents is a likely consequence of the core symptoms of ADHD, such as inattention and impulsivity. Many ADHD patients exhibit risk-taking behaviour that can also lead to substance abuse and criminal acts. In fact, the study shows that the mortality rate was eight times higher for ADHD patients with antisocial tendencies, conduct disorders and substance use disorder.
The researchers also found that the risk of premature death increases further in patients who are diagnosed in adulthood: "Previously, ADHD was considered a children’s disorder. But it turns out that patients who are diagnosed with ADHD when they are 18 or older have a five times higher risk of dying of unnatural causes," explains Dalsgaard.
The research results also indicate that female ADHD patients have a slightly higher mortality rate than their male counterparts. According to Dalsgaard, it may be due to the fact that women show less observable symptoms, and therefore only the most severe cases are identified.
"A lot of boys with ADHD are hyperactive, display conduct disorders and disruptive behaviour. These are very visible symptoms that affect their surroundings. Girls with ADHD, on the other hand, tend to act sad and concerned, suffer from anxiety disorder and show symptoms of depression. Such coexisting symptoms may not cause problems for others – and that’s why girls or women with ADHD are often overlooked," emphasises Dalsgaard.
"In Denmark, clinical practice is more restrictive in diagnosing ADHD compared to other European countries and the US, and it is a well-documented fact that in Denmark we still do not treat everyone who suffers from ADHD."
According to Dalsgaard, it is crucial that ADHD is taken seriously: "It's a neurobiological condition that has severe consequences for those who suffer from it – to such an extent that they can actually die from it. So we need to address the condition properly, give it the necessary amount of attention and make sure that we're able to identify those who suffer from ADHD as early on as possible and provide optimised treatment options," he concludes.
[link url="http://bss.au.dk/currently/news/news-item/artikel/people-with-adhd-are-twice-as-likely-to-die-prematurely/"]Aarhus University material[/link]
[link url="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(14)61684-6/abstract"]The Lancet article summary[/link]
[link url="https://www.medicalbrief.co.za/?s=ADHD"]Archived articles on ADHD[/link]