The document explores the neuroanatomical basis of depression and bipolar disorder, highlighting the complex interactions between brain regions, neurotransmitter systems, and neural circuits. Depression, affecting millions globally, is characterized by persistent low mood, while bipolar disorder involves extreme mood swings between depression and mania. The document discusses the structural and functional abnormalities in key brain regions implicated in mood regulation, emphasizing the importance of understanding these changes for effective diagnosis and treatment. Treatment options include medications and psychotherapy targeting neurochemical imbalances and maladaptive thinking patterns, respectively.