Van Gogh never ate (yellow) paint to become more cheerful, quite the contrary! During his time at the institution in Saint-Rémy, he wrote in a letter to Theo: ‘It appears that I pick up filthy things and eat them, although my memories of these bad moments are vague’.
The medical notes of Dr Peyron, Vincent’s physician, reveal that Vincent wanted to poison himself by eating paint and drinking turpentine. That’s probably why he wasn’t allowed into his studio while he was suffering from his attacks.