The report comes from Francis McMahon, M.D., of the National Institute of Mental Health (NIMH).
"Medications to treat depression are widely available, but no one treatment works for everyone," McMahon says in a news release
There is no test to predict which of the various antidepressants will work best for a particular patient. It can take trial and error over weeks or months to find the right one. "We are seeking to better understand why this is the case, and, using genetic markers, develop personalized treatments that give patients the best chance at remission," McMahon says.
"Ultimately, our goal is to put together a panel of genetic markers that can guide treatment decisions and help doctors choose an antidepressant that will work best for an individual patient," he says. That panel of genetic markers isn't complete yet. But McMahon's findings may help.
McMahon studied data from 1,953 adult patients treated with the antidepressant Celexa.
The patients' genes were screened. Certain variations in two genes were associated with response to Celexa treatment.
One of those genes is the HTR2A gene, which is linked to serotonin, a brain chemical boosted by some antidepressants, including Celexa. The other gene, called GRlK4, is linked to glutamate, another brain chemical.
Along with past research, the data "make a compelling case for key roles of HTR2A and GRlK4 in the mechanism of antidepressant action," writes McMahon. "Genetic markers that identify individuals at high risk for treatment failure or particular side effects may ultimately help guide treatment decisions," he writes.
McMahon's findings were presented in Hollywood, Fla., at the American College of Neuropsychopharmacology's annual meeting.
Depression is a common but often treatable disease. In any year, about 21 million U.S. adults — nearly one in 10 — are depressed, according to the NIMH.
The NIMH lists these warning signs of depression:
The exact cause of depression isn't known. It may be a combination of genetic and environmental factors. If you suspect depression, seek help. Talk to your doctor for depression screening. Treatments may include medications and/or talk therapy.
If you already know you have depression, you may want to use these tips from the NIMH:
Remember that positive thinking will replace the negative thinking that's part of the depression as your condition responds to treatment.
The NIMH offers these do's and don'ts for people who have a depressed friend or family member:
SOURCES: American College of Neuropsychopharmacology's annual meeting, Hollywood, Fla., Dec. 3-7, 2006. News release, GYMR. National Institute of Mental Health: "Depression."
By Miranda Hitti
Reviewed by Louise Chang, M.D