contraceptives, and cardiac medications. Chronic illnesses: Medical problems such as a thyroid deficiency and even a bout with the flu can cause chemical imbalances in the brain, which can cause depression. Melancholy temperament: Orderly, gifted, and creative, the person with a melancholy temperament can, at the same time, be moody, overly sensitive, and self-deprecating. Because they are analytical, critical, and hard to please, they can take everything too seriously—too personally—and quickly become