Adults with ADHD: an increased risk of dementia

Many adults with ADHD and attention deficit remain under diagnosed, which can lead to significant difficulties with focus, paying attention and impulsive behaviour.

New research suggests there is also a higher price to pay: A higher risk of dementia.

After Alzheimer’s disease, the second most common form of dementia is dementia associated with Lewy bodies, also known as DLB. DLB accounts for around 10% of all dementia. It too is often under diagnosed, because some of the characteristics of this particular illness are very similar to both Alzheimer’s and Parkinson’s disease.

A study in Argentina has found that adults with ADHD and attention deficit have three times the risk of developing this form of dementia.

DLB is a dementia associated with progressive mental and physical disability. Those with DLB may experience visual hallucinations. They may also have motor difficulties, causing problems with activities of daily living and movement problems that can fluctuate on a daily basis, in the same way as those living with Parkinson’s disease can experience.

The association between adult ADHD and this form of dementia is thought to be because they share the same problems in neurotransmitter pathways. In other words they share a common problem with how our brain cells or neurons communicate with each other.

In the study, 360 people with dementia (109 with DLB and 251 with Alzheimer’s disease) and 149 healthy controls were matched for age, sex and education. Assessments of known or historical evidence of symptoms of ADHD showed that impulsivity and hyperactivity (the major symptoms of ADHD) was significantly higher in the DLB group.

This is the first evidence showing a clear link between these two conditions. It is now believed that there is a common pathway associated with both in that a person with adult ADHD is at higher risk of progressing to DLB at a later age.

What isn’t known from this study is whether those adults with ADHD can reduce their relative risk of dementia through improved management or treatment of their ADHD. Hopefully further research will reveal if this is the case or not.

Ref:

A. Golimstok, J. I. Rojas, M. Romano, M. C. Zurru, D. Doctorovich, E. Cristiano. Previous adult attention-deficit and hyperactivity disorder symptoms and risk of dementia with Lewy bodies: a case-control study. European Journal of Neurology, 2011; 18 (1): 78 DOI: 10.1111/j.1468-1331.2010.03064.x