Melancholia

Melancholia, or melancholy, is a concept found throughout ancient, medieval and premodern European medicine describing a condition of markedly depressed mood, bodily complaints and, in some cases, hallucinations and delusions. Historically attributed to an excess of black bile in the body's four humors, the concept is treated in psychiatry today as an early conceptual ancestor of what is now classified as melancholic depression, marked by low mood, low self-esteem, fatigue, insomnia and loss of pleasure. Its modern understanding attributes such depressive states to a combination of genetic, environmental and psychological factors.