A new study has identified a secondary benefit to a specific type of antidepressant. The Science Daily recently released a report concerning the use of amitriptyline, a widely used antidepressant and pain medication. This particular drug has been shown to impersonate the brain’s own growth factors. Researchers at Emory University School of Medicine made this discovery and the results were slated to appear in the June 26 issues of the journal Chemistry & Biology. First introduced in the 1960s, amitriptyline and other tricyclics are thought to exert their effects through the process of increasing the levels of the messenger chemicals serotonin and norepinephrine in the brain. However, there is a delay that is required for antidepressants to work. It is this delay that has led scientists to the concept that a secondary effect, or the pushing of neurons to survive and grow, must occur indirectly. In effect, the fact that this particular drug has the ability to directly stimulate the molecules that help neurons grow and resist toxins indicates that there is a separate mechanism by which some antidepressant and pain relief compounds happen to function. To come to this conclusion, Keqiang Ye, PhD, an associate professor of pathology and laboratory medicine at Emory, and his colleagues set out to identify those chemicals that could imitate a specific protein in the brain, the NGF or nerve growth factor. This particular protein has been used experimentally in both Alzheimer’s and diabetes patients. The challenge is that NGF cannot cross the blood-brain barrier and as a result, has puzzled researchers with the side effects that it causes. “We were surprised to find that amitriptyline has these same properties,” Ye said. “This is an antidepressant that has been used for decades.” Tests completed during this research showed that amitriptyline could protect neurons from oxygen and glucose deprivation or the toxin kainic acid. This was the only antidepressant drug that could duplicate NGF’s ability to stimulate neurons.