02. A Diagnostic Test for Effective Antidepressant Drugs

Francis Lee
When a drug is prescribed for a depressed or anxious person, it can take weeks to find out if the drug works. Most psychotropic drugs take weeks to take effect even when they do work. This long process can be agonizing for a patient already suffering from hopelessness and anxiety that accompany depression. Researchers at the Weill Cornell Medical College offer a glimmer of hope. Led by Francis S. Y. Lee, Psychiatry/ Pharmacology, the team made a breakthrough discovery that may lead to the first diagnostic test to guide the treatment of depression. The test would involve sampling the patient’s DNA and looking for a variant of the gene coding a protein called Brain Derived Neurotrophic Factor (BDNF). If the patient’s genes carry the variant, then it is unlikely that the patient would respond to the most commonly used class of antidepressant drugs, which include fluoxetine (Prozac™), citalopram (Celexa™), paroxetine (Paxil™), and sertraline (Zoloft™).
Early test results based on a transgenic mouse engineered by Cornell scientists indicate that mice with the normal BDNF gene responded the antidepressants. Mice with the variant gene were much less responsive to antidepressant drug treatment. These results are promising evidence that the presence of the genetic BDNF variant in animals may impact response to antidepressants. While a potentially significant breakthrough, current findings with mice cannot yet guide antidepressant treatment decisions. More research is needed before this test will be available for humans.