ADHD and cognitive decline may be connected, according to a new study.
Alzheimer’s disease is a tragic obstacle for individuals and their families to face in life. The cognitive decline that comes with Alzheimer’s makes it difficult for those affected to continue on with the basic components of day–to–day life. While Alzheimer’s remains without a cure and is not completely understood, recent studies have demonstrated that there may be a link between Alzheimer’s and a predisposition for attention-deficit hyperactivity disorder (ADHD).
Links between these kinds of conditions are hard to nail down, largely due to the logistical constraints of studying such things. For one thing, there is a long period of time that needs to pass for the study to uncover anything meaningful, as Alzheimer’s is going to develop over an extended time in most cases. So, there needs to be follow-up over the long term, which can be expensive to manage and hard to control for the many variables involved.
With that said, a longitudinal study was conducted that managed to show a possible connection between cognitive decline and the genetic predisposition for ADHD. Often, ADHD is thought of as something that impacts young people – and it does – but it is an issue for older individuals as well. In fact, it is believed that perhaps more than 2% of all adults over the age of 50 have the condition and there are probably more individuals who haven’t been diagnosed. ADHD hasn’t always been as frequently diagnosed as it is today. While the extent of the studies that have been performed so far does not range far enough to prove any kind of causal connection, there is enough to warrant further investigation.
The study that was used to demonstrate a possible connection between these two conditions leaned on advanced genetic science to do its work. First, it used what is known as an ADHD polygenic risk score, which evaluates how many gene variants that point to ADHD risk are present in an individual. While polygenic risk scores are not perfect, they do provide insight that can be used to highlight how likely an individual is to be impacted by ADHD.
With this testing in use, it was then possible to track the ongoing cognitive function of people in the study for years. Within the six-year period for follow–up testing, those who had a higher risk score in the initial polygenic testing did prove to be more likely to face a higher level of cognitive decline. Specifically, tests that evaluated memory showed more decline for the high ADHD risk group than the general population.
There is a lot of ground to cover and work to be done before any kind of link is confirmed between ADHD and Alzheimer’s. The next step may be to work on a study that evaluates the biomarkers of Alzheimer’s disease within a set of individuals that had been diagnosed with ADHD at an early age in life, rather than using the polygenic risk score to look for ADHD in those who are already in the later stages.