Windsor Star

BYLINE: Veronique Mandal Star Health-Science Reporter

Scientists attempting to design brain-shielding drugs for the mentally ill are inching closer to curing schizophrenia.

"It could be tomorrow but it could also be 20 years from now," said Dr. Barry Jones, a researcher with the pharmacutical firm Eli Lilly in Toronto.

Understanding the path to a cure begins with understanding how drugs work on the schizophrenic brain. Anti-psychotics block the overproduction of the chemical dopamine, particularly in the limbic system, an old part of the brain which causes psychotic symptoms -- voices and paranoid delusions. Newer drugs also treat more emotional symptoms such as withdrawal and cognitive dysfunction. And they reduce the debilitating motor side-effects which can produce Parkinson-like symptoms such as the shakes.

The drugs also block another receptor for a chemical called seratonin which makes the frontal cortex of the brain more active. In schizophrenia the frontal cortex is slow and affects emotion and cognitive functioning.

The frontal cortex is the most highly developed part of the brain. It develops last and is not complete until the mid-20s, when schizophrenia typically develops.

"This is why schizophrenia could develop in younger children but is not evident until the late teens," said Jones. "It gives us our humanity, abstract thought, motivation and decision-making. It's silent but dramatic. Psychosis is the noisy part."

Because repeated psychotic events destroy grey matter, Jones said it's important to develop new drugs to prevent it. A chemical in Lilly's drug olanzapine appears to do that in a small way.

"The aim is a brand new drug to protect the brain from psychosis," he said

Once the genetics of schizophrenia are better understood, Jones expects the next stage to be a cure.

Traditionally, doctors have had difficulty keeping schizophrenics on their meds. Anti-psychotic drugs cause everything from drooling and lethargy to gross weight gain and possible links to heart disease and diabetes.

Many schizophrenics get fed up having to take a dozen or more pills a day.

McGill University psychiatrist Dr. Howard Margolese, a leading researcher in the field, said while it's preferable to have patients on fewer medications, it often takes several to deal with the symptoms.

"All anti-psychotics are effective against the positive symptoms of schizophrenia but we have to use an anti-depressant if the person is depressed and anti-anxiety medication if they're agitated and sometimes they need a drug to counteract the side-effects," said Margolese.

A study in the British Medical Journal said the average annual cost of keeping a person on anti-psychotics in Canada is $4,500. The average cost to hospitalize that person is $39,000.

Newer drugs are more expensive and it can take years for patients to be put on them. It is estimated that up to 60 per cent of Canadians remain on older medications.

The newer drugs cost on average $2,000 to $10,000 per year compared with $139 to $555 for drugs such as haldol, ORAP and loxapac. Prescription drug plans vary across the country, but some demand use of less expensive medications.