Lecture 29 Introduction to Depression

In this lecture I discuss modern neurogenic theories of depression in which stress and anxiety have been shown to disrupt neuronal health and cause the lose of functional synapses in the hippocampus and prefrontal cortex. Depression is no longer thought of as a chemical imbalance, but a neurodegenerative disorder in which increases in cortisol and reductions in BDNF damage neurons and reduce neurogenesis. The focus is now on how we can reduce cortisol release associated with stress and increase BDNF levels. This new theory provides opportunities to understand how diet and exercise can influence risk for depression.