Depression, for one, as been attested and treated as an illness since ancient times. Until fairly recently it was referred to as "melancholia," from the Greek for "black bile." (For citation purposes, see Robert Burton's 17th century text, recently released as "Some Anatomies of Melancholy). The symptoms have never changed--lethargy, apathy, trouble sleeping and eating, suicidal tendencies.

To understand how melancholy was treated as an illness, you have to understand the theory of the four humors. Until the advent of "modern" medicine, people believed that the human body was powered by four liquids, or humors: blood, phlegm, yellow bile, and black bile. Each of these humors was associated with certain personality qualities, and each person's unique balance of humors was thought to determine their individual character. Blood was associated with hope, courage, and cheerfulness; phlegm with patience and thoughtfulness; yellow bile with ambition, restlessness, and anger; black bile with seriousness, analytical thought, cynicism, and moroseness. If your personality was extreme in one of these ways, you were thought to have an excess of the related humor.

Now, this doesn't sound very medical, but you have to remember that at the time you're thinking of, this was the standard model. And frankly, they weren't too far off--they understood that depression was caused by a chemical imbalance in the brain, they just didn't know which ones. Many medical treatments, especially for mood disorders, involved altering or regulating a person's balance of humors. This was done mostly through diet, as different foods were thought to promote the production of different humors. According to Burton, beef and pork are extremely nutritious but provoke a lot of humors--good for hearty men who do a lot of physical labor, but harmful to those who lead a more sedentary life. All milks and cheeses (except donkey's milk) increase melancholy, which is healthy in children but dangerous in adults. Most meats seem to increase melancholy, according to Burton, but even some vegetables--cucumber, cabbage, onion, garlic.

This sounds a little "Chicken soup for the soul" here, but the ancients were wrong about some things and right about others--for instance, Hippocrates left instructions on how to use willow bark extract to treat headaches and fever, a treatment we now refer to as Aspirin.

I'd like to know how bipolar people were perceived.