Grant: CIHR Fellowship

Depression is a major public health concern, affecting over 1.5 million Canadians each year and resulting in tremendous personal and societal costs. After a person recovers from an episode of depression, they remain at high risk of becoming depressed again in the future. It is therefore imperative that researchers identify factors that make a person more vulnerable to relapse after experiencing depression. Executive control refers to a set of cognitive processes that allow people to selectively process information. Executive control is crucial for other cognitive functions like planning and decision-making. Previous research has found that people who are depressed prioritize the processing of negative information compared to people who are not depressed. In other words, people who are depressed have negatively biased executive control. Research suggests that when people recover from depression, they no longer show negatively biased executive control. However, it has been proposed that stress may activate depressive cognitive processes in previously depressed people. During periods of stress, previously depressed people may revert to selective processing of negative information, which may in turn increase their risk of prolonged negative mood and relapse to depression. The objectives of this study are to: 1) evaluate whether previously depressed people show negatively biased executive control when in a state of stress compared to when not in a state of stress; and 2) examine whether stress-induced biases in executive control predict future increases in depression symptoms among previously depressed people. This study has the potential to identify a novel cognitive risk factor for the recurrence of depression. Ultimately, this knowledge will help us to identify people who are most at risk of repeated episodes of depression, and develop targeted treatment approaches to reduce this risk.