Melancholia or melancholy (from µέλαινα χολή , meaning black bile) is a concept found throughout ancient, medieval and premodern medicine in Europe that describes a condition characterized by markedly depressed mood, bodily complaints, and sometimes hallucinations and delusions.
Melancholy was regarded as one of the four temperaments matching the four humours. Until the 18th century, doctors and other scholars classified melancholic conditions as such by their perceived common cause – an excess of a notional fluid known as "black bile", which was commonly linked to the spleen. Hippocrates and other ancient physicians described melancholia as a distinct disease with mental and physical symptoms, including persistent fears and despondencies, poor appetite, abulia, sleeplessness, irritability, and agitation. Later, fixed delusions were added by Galen and other phycisians to the list of symptoms. In th