An 'unusual' risk factor linked to a higher risk of developing Parkinson's disease after the age of 50 has been discovered

A new study has found that the risk of developing Parkinson's disease is at least twice as high in those who suffer from anxiety, compared to those who do not suffer from it.

The study investigated whether there was a link between people over the age of 50 who had recently developed anxiety and a subsequent diagnosis of Parkinson's disease.

The research team from the University of California, Los Angeles, used UK primary care data between 2008 and 2018 and evaluated data from 109,435 patients who developed anxiety after the age of 50 and compared it with data from 878,256 matched people who did not suffer from anxiety.

The researchers then tracked the presence of Parkinson's disease traits, such as sleep problems, depression, tremors and poor balance, from the point of their anxiety diagnosis until one year before the date of their Parkinson's diagnosis, to help them understand each group's risk of developing Parkinson's disease over time and what their risk factors were.

The team made sure to adjust the results to take into account age, gender, social deprivation, lifestyle factors, severe mental illness, head trauma and dementia, which may influence the likelihood of developing the condition in people with anxiety.

As a result, they found that the risk of developing Parkinson's disease was twice as high in people with anxiety, compared to the control group.

They also confirmed that symptoms such as depression, sleep disturbance, fatigue, cognitive impairment, low blood pressure, tremor, rigidity, poor balance, and constipation were risk factors for Parkinson's disease in those with anxiety.

Parkinson's disease is the second most common neurodegenerative condition worldwide, and it is estimated that it will affect 14.2 million people by 2040, said the study's lead author, Dr. Juan Pazo Avarez, a professor of epidemiology and health at the University of California.

He said: “It is known that anxiety is a feature of the early stages of Parkinson’s disease, but before our study, the potential risk of Parkinson’s disease in those over 50 years of age who experience new-onset anxiety was unknown. By understanding that anxiety and the features mentioned "Linked to an increased risk of developing Parkinson's disease over the age of 50, we hope we can detect the condition early and help patients get the treatment they need."

Parkinson's disease is known as the fastest growing neurodegenerative disorder in the world and currently affects about 10 million people worldwide.

This condition is a progressive disorder resulting from the death of nerve cells in a part of the brain called the substantia nigra, which controls movement.

These nerve cells die or weaken, and lose the ability to produce an important chemical called dopamine, due to the accumulation of a protein called alpha-synuclein.

“Anxiety has not been as well researched as other early indicators of Parkinson's disease,” said study co-author Professor Annette Schrage from the Queen Square Neurology Institute at UCL Parkinson's disease in its early stages, and this may lead to better treatment of the condition in its early stages."