Abraham Lincoln once said, "I am now the most miserable man living. If what I feel were equally distributed to the whole human family, there would not be one cheerful face on earth. Whether I shall ever be better, I cannot tell; I awfully forebode I shall not. To remain as I am is impossible. I must die or be better, it appears to me" (Hales 14). From President Abraham Lincoln to the common secretary, any variety of the human population is susceptible to the melancholia-related disease called depression. In fact, around 18 million Americans are affected by depression each year (Price). The first theory of this disease was conjured in the fourth century B.C. by Hippocrates, the Greek physician. Shortly after Hippocrates described depression as a result of "black bile on the brain" (Olshan 5). Aretaeus of Cappadocia, who lived in the second century B.C., made the first complete description. He opposed Hippocrates and related depression to psychological factors. To this day the exact cause of depression is unknown. However, a combination of genetic, biological, and the overlapping of psychological and environmental factors categorize the believed causes. Because depression contributes to the suicide rate, disturbs close friends and family, catalyzes an alcohol or drug problem, causes physical and psychological problems, and increases monetary costs, all of its effects are negative and plague today's society every day.
The first category of believed causes for depression is genetics. Many scientists and doctors believe that the development of depression is hereditary. Many studies have shown that depression seems to run in families from generation to generation. For example, studies have shown that brothers and sisters are 25 times more likely to get manic-depressive illness than the general population (Olshan 62). As supporting evidence, Lowell Weitkamp, a geneticist at the University of Rochester in New York, made a discovery through blood sample experimentation that there is a genetic link on the sixth chromosome between parents and their kids.