Melancholia is a mental illness. A person with melancholia has intense or long-lasting feelings of sadness, for no clear reason. In the 20th century, the term "melancholia" was mostly replaced by "depression" (also called Major Depressive Disorder).
The first person to describe melancholia was Hippocrates, in the 4th century BC. In his Aphorisms, Hippocrates wrote that all "fears and despondencies, if they last a long time", are symptoms of melancholia.
The name "melancholia" comes from the old medical belief that there are four basic liquids in the body (called humors). According to this belief, diseases happen when the humors are not balanced correctly in a person's body. Humors were also thought to determine personality types. According to Hippocrates, melancholia was caused by having too much black bile in the body. The name "melancholia" means 'black bile'. It comes from the Ancient Greek words μέλας (melas), meaning "dark, black", and χολή (kholé), meaning "bile".
Robert Burton, a16th century scholar, wrote in detail about the condition in The Anatomy of Melancholy (1621). It discussed melancholia from both literary and medical points of view. Burton wrote that music and dance were critical in treating mental illness, especially melancholia.
But to leave all declamatory speeches in praise of divine music, I will confine myself to my proper subject: besides that excellent power it hath to expel many other diseases, it is a sovereign remedy against  despair and melancholy, and will drive away the devil himself. Canus, a Rhodian fiddler, in Philostratus, when Apollonius was inquisitive to know what he could do with his pipe, told him, "That he would make a melancholy man merry, and him that was merry much merrier than before, a lover more enamoured, a religious man more devout." Ismenias the Theban, Chiron the centaur, is said to have cured this and many other diseases by music alone: as now they do those, saith Bodine, that are troubled with St. Vitus's Bedlam dance.
- Hippocrates, Aphorisms, Section 6.23
- Cf. The Anatomy of Melancholy, subsection 3, on and after line 3480, "Music a Remedy":
- "Humanities are the Hormones: A Tarantella Comes to Newfoundland. What should we do about it?" by Dr. John Crellin, Munmed, newsletter of the Faculty of Medicine, Memorial University of Newfoundland, 1996.
- Aung, Steven K.H., Lee, Mathew H.M. (2004). "Music, Sounds, Medicine, and Meditation: An Integrative Approach to the Healing Arts". Alternative & Complementary Therapies. 10 (5): 266–270. doi:10.1089/act.2004.10.266.CS1 maint: multiple names: authors list (link)