ADHD Increases Risk of Parkinson’s Disease

It is possible that Parkinson’s disease patients may bring future claims against former employers if they were exposed to pesticides or organophosphates in the course of their employment. However, most experts believe that Parkinson’s is caused by a combination of genetic and environmental factors.[i] A new study has investigated attention deficit hyperactivity disorder (ADHD) as an additional risk factor.

Parkinson’s disease is a degenerative brain disorder whereby dopamine-producing nerve cells, responsible for controlling body movements, are lost. This results in movements becoming slow and abnormal. 

The main symptoms of Parkinson’s are tremors, slow movement and muscle stiffness.  These usually develop gradually.

Currently, there is no cure for Parkinson’s, but physiotherapy, medication and surgery (in some cases) can help to control symptoms and improve quality of life.

In the recent study, researchers examined medical records from 1996 to 2016, regarding patients over the age of 20, who were either diagnosed with (31,796) or without (158,790) a diagnosis of ADHD.

ADHD is a behavioural disorder, often diagnosed in children between the ages of 6 and 12. It is thought that genetics play a role in ADHD onset, because parents and siblings of children with ADHD are likely to have the disorder themselves. 

Previous studies have found some differences between the brain structure of ADHD patients and those without ADHD. It has been intimated that the disorder disrupts the synthesis and release of dopamine in the brain. ADHD can be managed with medication and/or therapy

Researchers in the present study looked for brain disease in patients, including Parkinson’s.[ii]

They identified that patients diagnosed with ADHD were more than twice as likely to develop early-onset (between the ages of 21 and 66) Parkinson’s and Parkinson’s-like diseases as those without ADHD. Further, the risk was 6 to 8 times higher in patients who were prescribed ADHD medication. 

Lead researcher, Karen Curtin, highlighted that there is still uncertainty over whether the increase in Parkinson’s risk developed as a direct result of stimulant medications, the presence of any form of ADHD, or the presence of a more severe form of ADHD:

The increased risk we observed in people could be linked to having ADHD itself or perhaps a more severe form of ADHD, which may be more likely to be treated with medications’.[iii]


[i] Overview: Parkinson’s Disease. NHS. (Accessed 17 September 2018)

[ii]  Curtin, K. et al. Increased risk of diseases of the basal ganglia and cerebellum in patients with a history of attention-deficit/hyperactivity disorder. Neuropsychopharmacology 1 (2018). doi:10.1038/s41386-018-0207-5 (Accessed 19 September 2018)

[iii] ADHD may increase risk of Parkinson’s disease and similar disorders.  University of Utah, Health. (Accessed 19 September 2018)