Parkinson’s Risk Threefold Higher with Meth Use

the Psychiatry Advisor take:

Methamphetamine users are three times more likely to develop Parkinson's disease compared with non-illicit drug users, with this risk nearly doubling to fivefold among female users, study findings indicate.

The risk estimates are based on information from more than 40,000 health records from the Utah Population Database (UPDB) from 1996 to 2011.

In the retrospective study, Karen Curtin, PhD, a research assistant professor of medicine at the University of Utah School of Dentistry and associate director of the UPDB, and colleagues compared Parkinson's disease rates among individuals aged 30 years or older on Dec. 31, 2011, who were split into three cohorts: those whose health records indicated had used meth (n=4,935), those with a history of cocaine use (n=1,867), and an age- and sex-matched control population cohort without exposure to drugs or alcohol (more than 34,000).

Those with a medical history of alcohol dependence or using other illegal drugs were excluded. Parkinson's risk was not increased among the cocaine group, the researchers found.

"We feel comfortable that it's just the meth causing the risk for Parkinson's, and not other drugs or a combination of meth and other drugs," said study researcher Glen R. Hanson, DDS, PhD, a professor of pharmacology and toxicology.

Overall, women are less likely to develop Parkinson's than men. The reason for the higher risk the researchers observed in female meth users is not known. Fewer females use meth and often start using smaller amounts than men, but tend to escalate use more rapidly and are at greater risk for relapse, the researchers noted.

"If meth addiction leads to sharply increased incidence of Parkinson's in women, we should all be concerned," Curtin said.