Wednesday, June 20, 2007
The New York Times Science section, in a story by Dr. Richard Friedman, discusses research by scientists on personalized drugs. Focusing on depression, the article discussed how certain types of drugs for depression may work better for individuals depending on their biology.
Laura is a case in point. A successful management consultant in her late 30s, she sought help for lifelong depression. Her treatment began with four weeks of the antidepressant Lexapro, a selective serotonin reuptake inhibitor, or S.S.R.I., without any effect. Next, I switched her to Zoloft, another S.S.R.I., since the chance of response to another member of the same drug family is about 60 percent. Again, no response. Then we moved on to Wellbutrin, an entirely different type of antidepressant, but this didn’t work either. Laura was now ready to call it quits, and who could blame her?
After nearly three months, I had still not found an effective treatment for her. Then she came in one day and said her father had recently revealed that he had been depressed and had done well on Prozac, another S.S.R.I., and she wondered if she could try it. Within three weeks, she felt markedly better, and the symptoms of her depression began to melt away.
Instead of the hit-or-miss approach I had to use with Laura, it will soon be possible for a psychiatrist to biologically personalize treatments. With a simple blood test, the doctor will be able to characterize a patient’s unique genetic profile, determining what biological type of depression the patient has and which antidepressant is likely to work best.
Scientists have identified genetic variations that affect specific neurotransmitter functions, which could explain why some patients respond to some drugs but not to others. For example, some depressed patients who have abnormally low levels of serotonin respond to S.S.R.I.’s, which relieve depression, in part, by flooding the brain with serotonin. Other depressed patients may have an abnormality in other neurotransmitters that regulate mood, like norepinephrine or dopamine, and may not respond to S.S.R.I.’s.
This is very exciting news. The downside, I am sure that it is also extremely expensive.