The 36-year-old singer sought treatment at the residential trauma centre, Khiron House in Oxfordshire, in 2012 where he was diagnosed with a range of issues including PTSD, depersonalisation and derealisation, reported Female First.
"My brain had shut down due to overwhelming levels of anxiety. I couldn't even recognise my own face in a mirror. It was terrifying. It's basically an extreme fight-or-flight response," he said.
Young, who shot to fame when he won "Pop Idol" in 2002, blamed a number of issues for his disorders, including being bullied, hiding his homosexuality, separation from his twin Rupert at birth and addictions including love and shopping.
Young, however, said that seeking treatment has made him appreciate his success and realise how lucky he is.