Canadian hospital pioneers mental-health treatment
TheGlobeandMail.com – national – Canadian hospital pioneers mental-health treatment: Toronto psychiatric hospital to combine genetic testing with brain imaging
Jul. 07, 2009. Anne McIlroy
A Canadian psychiatric hospital will be the first in the world to use a combination of genetic testing and brain imaging to help determine the best course of treatment for patients with schizophrenia, depression, bipolar disorder and other mental illnesses.
A few dozen patients will take part starting in the fall, and the experimental program will slowly ramp up to include 100 people, says James Kennedy, director of the neuroscience research department at the Centre for Addiction and Mental Health in Toronto. If it proves successful, the program will be a step toward giving psychiatrists more precise tools to assess patients with common psychiatric conditions.
“It is a small revolution, a great opportunity to change, in a fundamental way, how we treat patients,” says Dr. Kennedy, who along with his colleague, Sylvain Houle, is leading the new research initiative.
In the genetic testing, the doctors will look for a number of genes that affect how fast many psychiatric drugs are broken down in the liver. Seven per cent of people who take the antidepressant Paxil, for example, metabolize it so slowly they have too much of the drug in their bloodstream at once, says Dr. Kennedy. This can cause such side effects as nausea and headaches. These patients need far lower doses of the drug, he says, sometimes as little as one-fifth of the normal dose.
In people with schizophrenia, the genetic tests can indicate if they are likely to suffer severe tremors from a class of antipsychotic drugs.
The brain scans will provide information about how quickly the drug gets into a patient’s brain and how well it gets absorbed, as well as a map of brain deficits.
“It is an enrichment. … It adds new kinds of information that in conjunction with the genetics information allows for a much better decision about which drugs at which dose to give the patient,” says Dr. Kennedy, who studies genes involved in mental illness.
Part of the work is experimental, an effort to understand how genes associated with 18 different psychiatric conditions affect how the brain functions and how it responds to different treatments.
Other centres are starting to use genetic testing in the treatment of mental illness, Dr. Kennedy says, but not in combination with positron emission tomography, or PET scans, which allow researchers to study neurochemical changes produced by drug therapies.
Treating mental illness is often a trial-and-error process, and side effects can make patients unwilling to stick with a treatment regime. If a drug doesn’t work, or causes serious side effects, patients can lose faith in their doctor.
The first year of treatment can be crucial, Dr. Kennedy says.
Genetic testing is relatively fast and cheap. It costs about $50 and the results are available in a few days.
Brain imaging is more expensive. The procedure costs $800 and Dr. Kennedy and his colleagues want to do two for each patient, one after treatment has started and one a few months later.
The new research initiative, known as neuroIMAGENE, is being funded by a $2.8-million grant from the Canada Foundation for Innovation. That grant is expected to be matched by one from the province of Ontario.
The program could save the health-care system money, Dr. Kennedy says.
For example, many patients with schizophrenia gain weight and develop diabetes while taking drugs now widely prescribed to treat the devastating illness, he says. If they could take older anti-psychotics, which are effective but can cause tremors, Dr. Kennedy says they would be less likely to get diabetes.
Genetic testing can show if patients have a high risk of suffering tremors if they take one of the older drugs. About 25 to 30 per cent of people with schizophrenia are susceptible to the side effect, he says.
A severe disturbance in the brain’s functioning, it is characterized by hallucinations, delusions, disordered thinking, an altered sense of self, a lack of motivation, a muted personality, depression and social withdrawal. The onset usually occurs in adolescence and early adulthood.
One of the most common psychiatric conditions, it is often under-diagnosed and under-treated. Depression is characterized by a pervasive depressed mood, a decreased ability to experience pleasure, and a loss of interest in a person’s usual activities. There are many associated symptoms such as significant weight loss or gain, loss of energy, problems concentrating, suicidal thoughts and disordered sleep. Diagnosis is based on the combination and severity of symptoms.
It is not a single disorder, but a category of mood disorders characterized by episodes of prolonged and profound depression alternating with periods of excessively elevated mood or irritability, known as mania. Between periods of high and low, sufferers can and often do lead productive lives. The disorder is commonly misdiagnosed as other forms of depression, which can lead to a worsening of symptoms from incorrect drug prescriptions.