Smile mask syndrome
Smile mask syndrome (Japanese: スマイル仮面症候群, Hepburn: sumairu kamen shōkōgun), abbreviated SMS, is a psychological disorder proposed by professor Makoto Natsume of Osaka Shoin Women's University, in which subjects develop depression and physical illness as a result of unnaturally prolonged smiling. == Origin == Natsume proposed the disorder after counselling students from the university in his practice and noticing that a number of students had spent so much time faking their smiles that they were unaware that they were smiling even while relating stressful or upsetting experiences to him.