Instead, the neuro-complex of the brain works as a unit.
Endogenous depression refers to depression that is caused by genetic factors.
Exogenous depression refers to depression clearly caused by environmental factors such as the loss of a loved one or losing your job. In TS, endogenous depression is usually the case. This notion is not true. Thus, the depression in TS is predominantly an endogenous type of depression and may have its onset long after the tics have disappeared. The endogenous depression, therefore, cannot be attributed to one's experience with tics, but rather it is an integral part of the expression of the Gts gene mutation complex.