"Justin has his up and down days like everyone else," a source close to Bieber told people.com.
"What he struggles with mostly is that he knows he is beyond blessed, but he has days when he feels empty and confused."
"He feels something is missing from his life that can't be bought. It's a missing feeling of happiness, he is very much grateful for his amazing life and especially for Hailey. It's difficult for him that he can't just enjoy everything and feel happy. He has been in treatment for this before," the source added.
The pop singer, 24, who was photographed visibly upset on multiple occasions last month, smiled while walking with his arm around Baldwin during a morning coffee run in Los Angeles last week.
Bieber, who recently shaved his head, was dressed casually in a blue jacket and grey sweatpants. Baldwin, 21, also opted for a low-key look, wearing a pair of black leather pants, a black sweatshirt and a white jacket.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)