Sigmund Freud grew up in Vienna, Austria and became a doctor of psychiatry. Early in his career he was interested in hypnosis as a cure for hysteria, believing that the symptoms were directly related to repressed psychological trauma. He started the practice of "free association," an effort to reveal unconscious emotions, and increasingly emphasized sexual development as the basis for psychological tension. Freud worked briefly with Carl Jung, was a professor in Vienna and co-founded the Vienna Psychoanalytical Society and the International Psychoanalytic Association. In 1938 he left Austria for England to escape Hitler's government. Freud battled mouth cancer the last several years of his life, but continued to smoke cigars, his trademark.