Grant: Master's Award: Canada Graduate Scholarships

Depression is a debilitating and recurrent illness that affects approximately 11% of Canadians at some point in their lives. Many people experience their first episode of depression as adolescents. Thus, the study of this age group is particularly important in understanding what causes depression when it first occurs. One biological system believed to be involved in causing depression is the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates the biological stress response and its function can be assessed by measuring the stress hormone, cortisol, in response to a laboratory-induced social stressor. Two additional factors that contribute to the onset of depression are childhood maltreatment and genetics. Both of these factors are also known to alter HPA axis functioning. Changes in HPA axis functioning may leave individuals more vulnerable to depression by changing how they respond to stressful life experiences. The objective of this study is to examine how a history of childhood maltreatment along with certain variants of the FKBP5 gene may alter HPA axis functioning in depressed and non-depressed adolescents. Our hypothesis is that adolescents with a history of childhood maltreatment, who also have a particular variant of the FKBP5 gene, will show a greater cortisol response to the social stressor than adolescents without both of these characteristics. Results from this study will help understand how people with a certain genetic makeup may be more vulnerable to the consequences of childhood maltreatment, which may leave them especially vulnerable to become depressed. Thus, this knowledge will assist clinicians in allocating resources to individuals at greatest risk for depression. Furthermore, this knowledge may inform the delivery of treatments currently under development to target the HPA axis.