In a bombshell exclusive, The ENQUIRER reveals that out-of-control pop punk JUSTIN BEIBER has a potentially deadly habit that may have already caused brain damage!

The 19-year-old singer made headlines around the world when he was busted for drag racing on a residential Miami Beach street on Jan. 23 and told cops he’d been boozing, smoking pot and taking anti-depressants.

Bieber also reportedly indulges in a dangerous homemade drug cocktail "sizzurp". Rehab specialist Dr. Damon Raskin, who has not treated the popped star, compared the deadly mix to heroin and oxycodone and said “can cause brain damage and even death.”

A former housekeeper for the “Baby” singer Tatiana Voziouk, told the UK tab “Sunday People” that Bieber kept the ingredients for the drug cocktail in his $10 million mansion in Calabassas, Calif., and another source says the star even kept a “sippy cup” with the mixture by his bed.

“Justin needs to be put in a psychiatric ward or lockdown rehab facility,” said a pal. “It’s worse than anyone knows. He needs help – and he needs it now!”

It’s a sad tale of yet another young celebrity barreling along a path of self-destruction, and The ENQUIRER has all the details. To read more about Bieber’s outrageous behavior, his homemade drug cocktail and why one of his fellow Canadians wants to ship him off to North Korea, be sure to pick up our latest issue – on newsstands now!