In this episode, I explain the biology, symptoms, causes and types of bipolar disorder (sometimes called bipolar depression). I discuss neuroplasticity and how the brain normally regulates mood, energy, and perceptions; then, I contrast that with the biology of bipolar disorder, which is characterized by extremes of energy and mood, e.g., mania and depression. I outline the mechanisms through which bipolar disorder manifests in the brain, including deficits of interoception and reduced connections between the parietal and limbic systems. I also outline how treatment options (such as lithium) work in part through homeostatic plasticity.’ I discuss not only lithium but also the treatment of bipolar with ketamine, different talk therapies, electroconvulsive therapy, transcranial magnetic stimulation, and nutraceuticals, including Omega-3 and Inositol supplementation. This episode should interest anyone who has or knows someone with bipolar disorder and, more broadly, those interested in how the brain works to create a balance between thoughts, energy levels, focus, and mood.