New clues on why some people with Parkinson's die sooner

The 12-year study included 230 people with Parkinson's disease, of whom 211 died by the end of the research. "Remarkably, time to death for these people took anywhere from two to 37 years from diagnosis so it's important we try to identify those risk factors that lead to an early death so we can find ways to increase a person's life expectancy," said Elin Bjelland Forsaa, MD, with Stavanger University Hospital in Norway and a member of the American Academy of Neurology.

The average time from the appearance of movement problems to death was 16 years. The average age at death was 81.

The study found that the risk of earlier death was increased about 1.4 times for every 10-year increase in age when symptoms began. People with psychotic symptoms, such as delusions and hallucinations, were also 1.5 times more likely to die sooner compared to those without these symptoms.

The odds of dying earlier were nearly two times higher for people who had symptoms of dementia in the study compared to those without memory problems. In addition, men were 1.6 times more likely to die earlier from the disease compared to women. Participants who scored worst on movement tests also had a higher risk of earlier death compared to those with the highest scores.

"Our findings suggest that treatments to prevent or delay the progression of movement problems, psychosis and dementia in people with Parkinson's disease could help people live longer," said Forsaa.

The study also found that taking antipsychotic drugs or drugs for Parkinson's disease had no negative effect on survival.

It is estimated that about one million people in the United States have Parkinson's disease.