Koro syndrome is a condition characterized by a fear of shrinking genitalia and premature death. This syndrome occurs primarily in men and women in Southern Asia. Historically, this condition arose from sexual promiscuity such as extra-marital sex, masturbation, inappropriate thoughts, and prostitutes. It is said that in certain cases the penis would actually shrink so far as to become inside the body of the man. It is accompanied by an irrational fear of death that can lead to psychosis. With many cultural bound syndromes, medical experts are still performing research to determine whether this is only a psychological disorder, or if there really are physiological symptoms as well. In the past, treatments were more spiritual, performed by healers, in order to cleanse a corrupt mind. It was said that symptoms would arise when the yin/yang of a marriage was disturbed (by nor having “normal intercourse”) and this balance must be reestablished in order to cure the disease.
I think that a lot of this syndrome has to do with a persons mental state, and the culture they are immersed in. The Chinese are a very traditional people who believe strongly in the power of gods and spirits that can interfere and control ones life. I believe that is a large part of the reason that we do not see this syndrome in other western cultures. The US is much more liberal and non-traditional than that of China.
However, there have been studies performed to test the biological validity of this syndrome. In one case, men were shown sexual stimuli as well as neutral stimuli, and the researcher measured a physical shrinkage in penis size, showing that the syndrome is not just mental. However, that study has not been repeated, and we cannot conclude that it is true of all patients with the mental symptoms of Koro.
Yap, P. M.. “Koro A Culture-bound Depersonalization Syndrome.” The British Journal of Psychiatry 111: 43-50.