Depression is a real illness that impacts the brain. Anyone suffering from depression will tell you, it’s not imaginary or “all in your head.” Depression is more than just feeling “down.” It is a serious illness caused by changes in brain chemistry. Research tells us that other factors contribute to the onset of depression, including genetics, changes in hormone levels, certain medical conditions, stress, grief or difficult life circumstances. Any of these factors alone or in combination can precipitate changes in brain chemistry that lead to depression’s many symptoms.