Meth Users Face 76% Higher Risk of Parkinson's Disease

Author: Center for Addiction and Mental Health
Published: 2011/07/29 - Updated: 2025/08/20
Publication Type: Research, Study, Analysis
Category Topic: Parkinson's Disease (PD) - Academic Publications

Page Content: Synopsis - Introduction - Main - Insights, Updates

Synopsis: This research from the Center for Addiction and Mental Health examined nearly 300,000 California hospital records spanning 16 years and found that patients hospitalized for methamphetamine or amphetamine use disorders faced a 76 percent higher risk of developing Parkinson's disease compared to the general population. The study, led by Dr. Russell Callaghan, provides the first concrete evidence of a suspected link between methamphetamine use and Parkinson's disease that scientists have theorized for three decades.

The research is particularly authoritative because it used innovative methodology by comparing methamphetamine users not only to a general population control group (appendicitis patients) but also to cocaine users, which helped isolate the specific neurological risks of methamphetamine versus other stimulants. This finding is especially valuable for healthcare providers, addiction specialists, and individuals in recovery, as it quantifies a concrete long-term health consequence while clarifying that the increased risk does not apply to patients taking prescribed amphetamines for conditions like ADHD at therapeutic doses - Disabled World (DW).

Introduction

Researchers examined almost 300,000 hospital records from California covering 16 years. Patients admitted to hospital for methamphetamine or amphetamine-use disorders had a 76 percent higher risk of developing Parkinson's disease compared to those with no disorder.

Main Content

Globally, methamphetamine and similar stimulants are the second most commonly used class of illicit drugs.

"This study provides evidence of this association for the first time, even though it has been suspected for 30 years," said lead researcher Dr. Russell Callaghan, a scientist with CAMH.

Parkinson's disease is caused by a deficiency in the brain's ability to produce a chemical called dopamine. Because animal studies have shown that methamphetamine damages dopamine-producing areas in the brain, scientists have worried that the same might happen in humans.

It has been a challenge to establish this link, because Parkinson's disease develops in middle and old age, and it is necessary to track a large number of people with methamphetamine addiction over a long time span.

The CAMH team took an innovative approach by examining hospital records from California - a state in which methamphetamine use is prevalent from 1990 up to 2005. In total, 40,472 people, at least 30 years of age, had been hospitalized due to a methamphetamine, or amphetamine, use disorder during this period.

These patients were compared to two groups: 207,831 people admitted for appendicitis with no diagnosis of any type of addiction, and 35,335 diagnosed with cocaine use disorders. A diagnosis of Parkinson's disease was identified from hospital records or death certificates. Only the methamphetamine group had an increased risk of developing Parkinson's disease.

While the appendicitis group served as a comparison to the general population, the cocaine group was selected for two reasons. Because cocaine is another type of stimulant that affects dopamine, this group could be used to determine whether the risk was specific to methamphetamine stimulants. Cocaine users also served as a control group to account for the health effects or lifestyle factors associated with dependence on an illicit drug.

"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," said Dr. Stephen Kish, a CAMH scientist and co-author.

To put the study findings into numbers, if 10,000 people with methamphetamine dependence were followed over 10 years, 21 would develop Parkinson's, compared with 12 people out of 10,000 from the general population.

"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," said Dr. Callaghan.

The current project is significant because it is one of the few studies examining the long-term association between methamphetamine use and the development of a major brain disorder.

"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," said Dr. Callaghan.

Center for Addiction and Mental Health (CAMH)

The Center for Addiction and Mental Health (CAMH) is Canada's largest mental health and addiction teaching hospital, as well as one of the world's leading research centers in the area of addiction and mental health. CAMH combines clinical care, research, education, policy development and health promotion to help transform the lives of people affected by mental health and addiction issues. CAMH is fully affiliated with the University of Toronto, and is a Pan American Health Organization/World Health Organization Collaborating Center.

Insights, Analysis, and Developments

Attribution/Source(s): This quality-reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by Center for Addiction and Mental Health and published on 2011/07/29, this content may have been edited for style, clarity, or brevity.