Sep. 23--People diagnosed with depression often have trouble finding a medication that works for them.

It's trial and error, and it can take a long time to find the right drug in the right dose that helps them deal with their depression.

But new genetic testing could go a long way to help physicians find the right medication for patients faster.

Mayo Clinic is conducting a scientific study at Franciscan Skemp Healthcare in La Crosse to determine if genetic testing helps physicians in selecting the right antidepressants and dosages.

"This could be a quantum leap in psychiatry," said Dr. Brian Proctor, a Franciscan Skemp psychiatrist who is part of the study. "I foresee genetic testing as one of the tools we will use in helping our patients."

Josiah Allen, the study coordinator at Mayo Clinic, said the right drug could prevent death or injury and serious side effects.

"With genetic testing, it may not be necessary to try three, four or five different medications before you find the right one," Allen said. "I think it will change the face of prescribing medication."

Mayo developed a genetic test, known as cytochrome P450, which pinpoints genetic factors that may affect a patient's response to various drugs.

Proctor said the test uses a blood sample to determine a patient's ability to metabolize certain drugs.

"It tells us if you're a fast or slow metabolizer, so we can rule out some drugs we shouldn't try," Proctor said. "It can lead to fewer side effects and better efficacy."

Allen said if your body uses a drug too slowly, it can cause more side effects, or even a toxic reaction, which may lead you to stop using the drug.

If your body uses the drug too quickly, the drug may be eliminated from your body before you get a chance to benefit from it, he said.

"The test tells us if the medication is going to stay in the system and be adequately metabolized in the liver," Proctor said. "And the sooner the medication gets into the system at a dose that works, patients will be happier."

For dosing, a person with a slower metabolism will require smaller doses, he said.

Bob Hillary, director of behavioral health outpatient services at Franciscan Skemp, said people with depression typically try up to six medications while searching for the right one.

"If the medicine is right and the psychotherapy is right, it can change the lives of people," Hillary said. "It can prevent death, side effects and all the frustration patients face in finding the right medication."

Proctor said getting the right drug to patients faster will improve quality of life and productivity as well as decrease patient visits and substance abuse.

The research study will enroll 200 patients, ages 18 to 85, over one year at sites in La Crosse and St. Paul.

One group of patients will get the blood test and physicians will get back the results immediately so they can decide how to proceed with treatment. The other group also will get the genetic test, but won't get that information until after the study is completed.

"Our study will be the first to show how doctors and patients react to this information," Proctor said.

He said he is recommending patients who are changing medications to participate in the study.

Allen said patients are getting a free test, which costs $1,200 to $1,300.

Terri Pedace, research operations supervisor at Franciscan Skemp, said Franciscan Skemp is participating in another study using genetic testing to determine use of the best cancer drug.

"This is one of the most exciting things for us," Pedace said. "Genetic testing will have a real impact on psychiatry and patient safety and will be a better tool to guide physicians."

The study also will track hospitalization and emergency room visits because Pedace said she expects genetic testing to save hospital days and reduce costs.

The genetic test is part of medical care at Mayo, where 50 percent of hospitalized patients diagnosed with depression get the test, Allen said.

Allen said genetic testing is part of personalized medicine, a rapidly emerging field which is changing health care.

Currently, treatment is determined by standard protocols with an average number of successful outcomes and an average number of treatment failures, Allen said.

But he said by uncovering genetic differences in DNA, patients can be treated uniquely after determining how their bodies react to medication.

"It really is individualized treatment," Allen said.

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