Jonathan Downar, a psychiatrist and neuroscience expert who co-authored the textbook 'Brain and Behavior,' joins the discussion on depression's complexity. He delves into how depression can be an evolutionary survival mechanism and the intriguing connections between brain function, emotional resilience, and societal influences. The conversation also covers innovative treatments like transcranial magnetic stimulation (TMS), challenging traditional views on serotonin, and the need for a holistic approach to mental health, much like addressing social issues linked to tuberculosis.