With his family's support, Josephson began to pursue art professionally at the age of sixteen, enrolling at the
Royal Swedish Academy of Fine Arts. His primary instructors there were
Johan Christoffer Boklund and
August Malmström. He was there until 1876, when he received a Royal Medal for painting. Josephson's private life was tumultuous, however; by his late twenties, he was affected by
syphilis, his romantic life suffering as a result. Josephson was forced to discontinue pursuing a relationship with young model, Ketty Rindskopf. By the summer of 1888, he was beginning to suffer delusions and hallucinations, brought on by the progression of his illness. Residing on the
Île-de-Bréhat in
Brittany, where he had spent the previous summer with painter and engraver
Allan Österlind (1855–1938) and his family, he became involved in
spiritism, possibly inspired by Österlind's interest in occult phenomena. While in his visionary states, he wrote poems and created paintings that he signed with the names of dead artists. Some of his best known and most influential works were created during this period.{{cite web|url= https://forward.com/culture/129813/a-swede-among-the-sprites/|title= A Swede Among The Sprites |publisher= The Forward Association, Inc|author=Benjamin Ivry|date= August 4, 2010 Shortly after, Österlind took him back to Sweden and he was admitted to , a mental institution in
Uppsala. He remained there for several months. The diagnosis was
paranoia, but his condition would now most likely be called
schizophrenia . After being released, he continued to associate with his old friends, who did what they could to help him. His paintings had become rather distorted, but his earlier works were shown at exhibitions in Paris and Berlin, thanks to arrangements made by
Richard Bergh and
Georg Pauli, and he received several medals for them. As the years progressed, his physical health declined. First he developed rheumatic problems, which prevented him from painting. Then he was diagnosed with diabetes, which was the cause of his death in 1906. ==Legacy==