Manual: In a manual transmission, the problem is not so much the fluid degradation, but rather fluid contamination. This contamination occurs over time as the synchronizers, bearings and gears in the transmission wear out. The resulting metal particles then float around in the lubricant.
A lot of mental illnesses can have a genetic component, yes (eg. depression, bipolar disorder, anxiety, antisocial personality disorder, etc.).
Mental Health Mental Disorders Stress and problems with school, friends, and family can cause mental illnesses. Mental illnesses include: depression, bipolar disorder, schizophrenia, and phobias.