Bjerre is credited for introducing psychoanalysis and Freudian psychiatric concepts into Swedish medicine, which he presented to a 1911 gathering of the "Order of Swedish Physicians". He would later distance himself from a number of Freudian ideas. Bjerre believed that the workings of the conscious mind were more important than those of the unconscious, and felt that Freud placed too much emphasis on an individual's sex life. He believed that it was important for the psychiatrist to "be human", and to view and treat his patient in an holistic manner. Bjerre was also a major advocate of hypnosis.
Among his written works was an influential book which theorized on the recurring cycle of "psychic death and renewal" called Död och Förnyelse. He wrote a biography on Friedrich Nietzsche, and is remembered for his written correspondence with Freud and Carl Jung.