Individuals who abuse methamphetamine and other similar stimulants have a much higher risk of subsequently developing Parkinson’s disease, compared to people who don’t, researchers from CAMH (Center for Addiction and Mental Health) reported in the journal Drug and Alcohol Dependence.
Dr. Russell Callaghan and team gathered data from nearly 300,000 hospital records in California over a 16-year period. They compared 40,472 individuals who had been hospitalized for methamphetamine and amphetamine-related conditions with 207,831 who were admitted with appendicitis and 35,335 who were hospitalized for cocaine-use disorders.
They found that those who had been hospitalized for methamphetamine or amphetamine-use disorders were 76% more likely to later on develop Parkinson’s disease than the other patients.
The authors explained that methamphetamine or other amphetamine-like stimulants are the second most popular illicit drugs people use.
Dr. Callaghan said:
“This study provides evidence of this association for the first time, even though it has been suspected for 30 years.”
Parkinson’s disease develops when the human brain cannot produce dopamine – a brain chemical – properly. Studies on animals have shown that methamphetamine harms the dopamine-producing areas in the brain. Scientists have long wondered whether the same applies to humans.
As Parkinson’s disease develops later on in life, during old age and sometimes middle age, it has been difficult to track large numbers of people with methamphetamine abuse over a long period to establish a link.
The researchers decided to examine hospital records in California, where methamphetamine use is high. They looked at records from 1990 to 2005, involving 40,472 individuals aged 30+ years. They had all been admitted to hospital due to a methamphetamine or similar type of stimulant disorder. As mentioned above, they were compared to hospitalized patients with appendicitis, as well as those with a cocaine use problem.
They wanted to evaluate the cocaine users because it is also a stimulant that affects dopamine – they could be used to find out whether the risk was limited to methamphetamine stimulants.
Co-author Dr. Stephen Kish, said:
“It is important for the public to know that our findings do not apply to patients who take amphetamines for medical purposes, such as attention deficit hyperactivity disorder (ADHD), since these patients use much lower doses of amphetamines than those taken by patients in our study.”
The researchers found that over a ten-year period:
- 21 in every 10,000 methamphetamine dependent people develop Parkinson’s disease
- 12 in every 10,000 people from the general population develop Parkinson’s disease
Dr. Callaghan said:
“It is also possible that our findings may underestimate the risk because in California, methamphetamine users may have had less access to health-care insurance and consequently to medical care.
Given that methamphetamine and other amphetamine stimulants are the second most widely used illicit drugs in the world, the current study will help us anticipate the full long-term medical consequences of such problematic drug use. “
“Increased risk of Parkinson’s disease in individuals hospitalized with conditions related to the use of methamphetamine or other amphetamine-type drugs”
Russell C. Callaghana, b, Corresponding Author Contact Information, E-mail The Corresponding Author, James K. Cunninghamc, Jenna Sykesa and Stephen J. Kish
Drug and Alcohol Dependence doi:10.1016/j.drugalcdep.2011.06.013
Written by Christian Nordqvist