The theory is that in the brains of people suffering from severe depression, the enzyme monoamine oxidase breaks down too much of a group of mysterious brain chemicals called .
A variation in a gene known as VMAT2--for vesicular monoamine transporter--seemed to be directly related to how the volunteers scored on the self-transcendence test.
Some scientists point to high testosterone levels combined with low monoamine oxidase inhibitors, which regulates dopamine.