First, even if all the rules are followed, there is a risk of mental illness. The reason is that there are pathologies in which heredity plays an important role. For example, schizophrenia. But there are rules that will help reduce the risk of developing mental illness. It is important to avoid injuries to the skull, as brain injury in the future manifests itself as psychotic problems. You should not drink too much alcohol, as it has been proven to have a bad effect on the psyche.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.