When most people say “depression,” they mean unipolar major depression, which is the subject of this book. Other names for unipolar major depression include clinical depression, major depressive illness, major depression with melancholic features, or simply unipolar depression.
These terms all refer to the same illness, located at the same place in the brain and affecting the same brain cells and chemicals. Other diseases that have “depression” in the title (like bipolar depression), or conditions where people feel sad or blue (like cancer, chronic pain, or brain injury) are different from major depression and involve different brain cells and brain chemicals than unipolar major depression.
