For the first time, researchers working with mice have identified a naturally occurring genetic mutation that affects brain levels of serotonin, a neurochemical linked to depression, anxiety and other psychiatric conditions.The discovery may help explain why some patients feel much better after taking serotonin-altering antidepressants such as Paxil, Prozac and Zoloft, and why others do not.The findings “suggest that there really are heritable differences in how the brain makes or synthesizes serotonin,” said Dr. Jerrold Rosenbaum, chief of psychiatry at Massachusetts General Hospital in Boston.
