In this video, I discuss the neuroscience of depression. First, I cover the serotonin hypothesis, which suggests depression is caused by low levels of serotonin in the brain, and I explain why this hypothesis does not fully explain what’s happening in the brain to cause depression. Then, I cover several other hypotheses, including those that focus on dysregulation in the HPA axis, immune system dysfunction, and impaired neuroplasticity and neurogenesis (linked to low levels of BDNF). Along the way, I also explain the mechanisms behind some common antidepressants, such as SSRIs.

Key points:

00:00 Introduction
1:01 Serotonin hypothesis
3:48 Flaws with serotonin hypothesis
4:57 HPA axis dysregulation
6:19 Immune system dysfunction
7:30 Neuroplasticity, neurogenesis, and BDNF

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