The provenance of a portrait of a wan-looking Vincent van Gogh giving side eye has been debated for decades. But experts have now concluded that Van Gogh himself painted it—while he was suffering from psychosis, according to artnet News. The 1889 work, which is owned by a museum in Oslo, Norway, was created by Van Gogh while he was in an asylum—he later described in a letter as “an attempt from when I was ill.” Louis van Tilborgh, a senior researcher at the Van Gogh Museum, said in a statement that “although Van Gogh was frightened to admit at that point that he was in a similar state to his fellow residents at the asylum, he probably painted this portrait to reconcile himself with what he saw in the mirror: a person he did not wish to be, yet was.”