For Immediate Release - July 26, 2011- (Toronto) - People who abused methamphetamine or other amphetamine-like stimulants were more likely to develop Parkinson’s disease than those who did not, in a new study from the Centre for Addiction and Mental Health (CAMH).
The 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 per cent higher risk of developing Parkinson’s disease compared to those with no diagnosis.
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.
Media Contact: Michael Torres, Media Relations, CAMH; 416-595-6015
The Centre 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 centres 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 Centre.
Over two thirds (68%) of people who had Parkinson's Disease reported nasal discharge. There was no relationship with age or severity of symptoms. The nasal discharge of over half (52%) of people with Parkinson's Disease was accompanied with light headedness. The symptom of lightheadedness is uncommon in people who do not have Parkinson's Disease, occurring in less than 1 in 10. Another recent study found similar results. The frequency of nasal discharge can lead to a reduction in the sense of smell, which is common in Parkinson's Disease. 
The Parkinson’s Disease Foundation has announced awards totalling more than $1 million for 11 novel research projects, which they claim are "designed to understand the cause(s) of and find a cure for Parkinson’s disease." The research ranges from basic science investigations to studies of potential new therapies and symptomatic relief. 
there are many. In Parkinson's Disease dysphagia has been found to be unrelated to age, gender or duration of Parkinson's Disease. However, dysphagia is very common in those people with sever motor skills. 
day. 
The VPS35 gene produces a protein called VPS35 (Vacuolar protein sorting-associated protein 35). The function of VPS35 is known, but it is not explained how this function not taking place causes Parkinson's Disease symptoms. Unlike other genetic causes of Parkinson's Disease, VPS35 appears to eventually cause Parkinson's Disease symptoms rather than make them more likely. 
When asked for their reasons the main reasons for participating in clinical trials were : to help the advance of science (63%), to gain access to a better treatment (56%), and to benefit others (51%). The major concerns were : the risk of adverse events (49%) and the negative effects of treatment (35%). 90% reported they had understood the informed consent. Only 64% understood what the