Grant: Fellowship - CIHR/Rx&D - Wyeth Pharmaceuticals Research Program

Depression is a condition with many biological causes proposed but not one of these has been verified. Alterations of the hypothalamic-pituitary-adrenal axis (a group of body regions associated with stress control among other functions) in depressed patients are extensively described. It also well known that drugs used to treat depression patients, called as antidepressants, are able to gradually normalize these aberrations seen in the hypothalamic-pituitary-adrenal axis. It has been shown that families containing one depression patient are more likely to present a second person with depression than families that do not present this disease. Therefore, this suggests a genetic component to develop depression. Other researchers have shown that some people will have different response using the same drug (such as a painkiller) as well as have some side-effects (just some people report dizziness after taking an antidepressant), what can also suggest a genetic component to respond to a medication. Taken together, this information shows that disease and its treatment can present a genetic susceptibility component (this does not mean that who has a specific gene will have the disease for sure, it is an increased chance to develop it in a presence of some other factor). In this study, it will be evaluated if different forms of genes that produce proteins in the hypothalamic-pituitary-adrenal axis are related with this susceptibility with depression and antidepressant treatment response. To do these analyzes depression patients' blood will be collected and using specific techniques their DNA will be read. After done all these analyzes we will be able to say if variations in genes at the hypothalamic-pituitary-adrenal axis are or not associated with depression and its treatment. This information can help physicians to manage better their depression patients as well as be used to develop new treatment strategies.