The SARA Project

Major depressive disorder (MDD) affects 3.7 million people in Canada over their lifetimes, and costs Canadians $21 billion per year. Progress in understanding depression has been hindered by the fact that different people experience often very different constellations of depression symptoms. The distinction between these very different manifestations of depression is an important one that may have a neurobiological and psychosocial basis; however, it is obscured in research that treats depression as a homogeneous category. Our goal in the SARA Project is to understand basic domains of functioning (or endophenotypes) that underlie depression and that have a clear psycho-biological basis. By understanding the different endophenotypes that might underlie the heterogeneous symptom presentations in depression, this may ultimately allow for the development of treatments that are individually tailored to people’s unique pathophysiology. In particular, we believe that depression is subserved by two endophenotypes: 1. a decreased (or blunted) biological sensitivity to stress, and 2. a decreased responsivity to rewarding or pleasurable stimuli in the environment. We believe that these two endophenotypes share underlying brain mechanisms and early environmental triggers, and result in a similar manifestation of symptoms in depression. This study is funded by the Ontario Mental Health Foundation and the Canadian Biomarker Integration Network for Depression (CAN-BIND) through the Ontario Brain Institute. We are actively recruiting depressed and non-depressed participants for this study. Please call 613-533-6003 for more details.

Theory of Mind

Depression is often associated with profound difficulties in interpersonal functioning and, specifically, a bias to perceive social interactions very negatively. This area of research, in collaboration with Mark Sabbagh, is investigating "theory of mind" as a basic social cognitive skill that might underlie this difficulty. Theory of mind is the everyday ability to make judgments about others' mental states (e.g., emotions, beliefs, desires). We have determined that clinically depressed patients are significantly worse at judging these mental states when compared to non-depressed controls. In direct contrast, people with a vulnerability to clinical depression who are not currently depressed are significantly more accurate in judging others’ mental states compared to non-depressed individuals. We have seen this enhanced theory of mind performance in individuals with mild sub-clinical depression (dysphoria), those with a past depression currently in remission, and those with a maternal history of depression. We have argued that these depression-vulnerable individuals may have a specific motivation to attend to others’ mental states, and we are currently following up on this research to determine the mechanism through which mild depression confers an advantage in mental state decoding. This research is funded by the Social Sciences and Humanities Research Council (SSHRC).

Canadian Biomarker Integration Network in Depression (CAN-BIND) Project

We are currently collaborating with a large network of researchers across Canada to find relevant biomarkers for pharmacological treatment response in major depression. The hope with this project is that it will lead to more effective assignment of patients to the treatments that will work best for them. We understand however, that biological factors in depression operate in an environmental context. Therefore, our lab's role in this project is to provide a detailed and fine-grained assessment of stressful life events in childhood and adulthood that may moderate the effect of biomarkers, including genomics, proteomics, and neural structure and function, on treatment response. We are currently investigating the impacts of COVID-19 stress on mood. This study is funded by the Ontario Brain Institute (OBI).