The serendipitous discovery of antidepressant medication has left many unanswered questions about how antidepressants work. We do not know precisely how antidepressants treat depressive symptoms, or why it can take up to several weeks to see meaningful improvements in symptoms. I am approaching these questions from a cognitive perspective, bridging the gap between neurochemical theory and clinical practice. Specifically, I am investigating the role of social behaviour in antidepressant effect, using methods such as Ecological Momentary Assessment (EMA).