US pop star Lady Gaga has revealed she suffers from post-traumatic stress disorder since being raped at the age of 19.
"I suffer from a mental illness - I suffer from PTSD," she told the Today Show on a visit to a homeless shelter for young gay people in New York.
"I've never told anyone that before," the star, now 30, added.
Lady Gaga said kindness was "the best way" to healing.
"The kindness that's been shown to me, by doctors as well as my family and my friends, it's really saved my life," the singer said, after bringing presents to the astonished teenagers at the centre.
"Meditation helps me to calm down," she said, adding that she was struggling with her mental illness "every day".
Lady Gaga later tweeted: "Today I shared one my deepest secrets w/ the world. Secrets keep you sick w/ shame.".