Tucked away in the corner of Edvard Munch’s (1863-1944) ‘The Scream’, renowned for being the world’s most harrowing painting,lies a tiny inscription: “Can only have been painted by a madman“. Infrared scans have now confirmed that the mysterious words are indeed those of the Norwegian artist and not the graffiti of a ridiculing critic.

“The writing is without a doubt Munch’s own,” explained curator Mai Britt Guleng of The National Museum of Norway, where the iconic painting is currently undergoing extensive conservation.

Scholars had long debated whether the markings were vandalism since the painting had caused controversy at the time for its radical expression of human fear. Painted in 1893, ‘The Scream’ depicts a man clasping at his face whilst his gaping mouth lets out a piercing scream.

According to his diaries, Munch based the painting on a walk he took with friends in Ekebergåsen. “Suddenly the sky turned blood red – I paused, feeling exhausted, and leaned on the fence,” wrote Munch. “There was blood and tongues of fire above the blue-black fjord and the city – my friends walked on, and I stood there trembling with angst – and I sensed an endless scream passing through nature.”

Munch is believed to have made the mysterious inscription in 1895 after he attended a meeting in which a medical student argued that only a mentally disturbed person could have created such an artwork.

“It’s a combination of being ironic, but also showing his vulnerability,” remarked Guleng. “He is actually taking this very seriously and he is hurt because there is a history of illness in his family, and he was very anxious, but he showed himself be marked by it.”

Throughout his childhood, Munch experienced great loss with both his mother and older sister passing away before the artist turned 14. His father suffered bouts of depression and another sister was diagnosed with bipolar disorder for which she was admitted to an asylum. Munch was later hospitalised in 1908 following a nervous breakdown.

Writing about his own mental health struggles, Munch revealed “for as long as I can remember I have suffered from a deep feeling of anxiety which I have tried to express in my art. Without this anxiety and illness, I would have been like a ship without a rudder.”

The new National Museum of Norway opens in 2022 and will become the largest museum in the Nordic countries.