Patients with Amphetamine Use Disorders Are More Likely to Be Hospitalized or Die from Parkinson’s Disease
Animal studies have shown that amphetamines, including methamphetamine, are toxic to dopamine-releasing brain neurons, but whether they play a role in the development of Parkinson’s disease (PD) in humans is not clear. Researchers analyzed a 16-year dataset (linked to state mortality records) of patients discharged from all California acute inpatient health facilities to determine whether patients admitted for amphetamine-related conditions (n=40,472) had an increased risk of PD-related hospitalization or death. Comparison groups included a population-proxy control of patients admitted for appendicitis (n=207,831) and a stimulant-drug control of patients admitted for a cocaine use disorder (n=35,335). Groups were matched by age, sex, race, date of incident admission, and number of subsequent admissions.
- There were 51 incident cases of PD in the amphetamine group and 29 incident cases of PD in the appendicitis control group in 1:1 matched samples of respective subjects (n=40,358) (hazard ratio [HR] of PD-related hospitalization or death, 1.76).
- There were 36 incident cases of PD in the amphetamine group and 15 incident cases of PD in the cocaine control group in 1:1 matched samples of respective subjects (n=40,358) (HR of PD-related hospitalization or death, 2.41).
Comments:The association between PD and amphetamine use disorders shown in this study provides epidemiologic evidence supporting the potential toxicity of amphetamines to dopaminergic neurons seen in animal studies. The evidence for this neurotoxicity appears to be specific to amphetamines and not to cocaine. This study did not address whether amphetamines prescribed at doses intended to address sleep and attention disorders increase PD risk, but this question warrants further study. Alexander Y. Walley, MD, MSc
Callaghan RC, Cunningham JK, Sykes J, et al. Increased risk of Parkinson's disease in individuals hospitalized with conditions related to the use of methamphetamine or other amphetamine-type drugs. Drug Alcohol Depend. July 25, 2011 [e-pub ahead of print]. doi:10.1016/j.drugalcdep.2011.06.013.