The star, who found critical acclaim on BBC hit The Fall, has revealed he turned to alcohol after the death of his mother Loran when he was just 16 years old in 1998.
Within 12 months, four of his friends died in a horrific car crash and he fell into a depression.
Speaking to Jay Rayner’s podcast Out To Lunch With… Jamie, 36, explained how he is “still dealing with” both tragedies.
The Irish hunk said: “Yeah, my mum died when I was 16. That was obviously a life-altering, insane, horrendous thing to happen.
“Then four of my mates killed themselves in a car crash when I was 17.
“I had a very rough couple of years that I guess I’m still dealing with both of [those] things today, every day.”
The Hollywood star added: “But I guess they were very acute still then and I drank a lot of everything but I had this summer where I’d go out a lot, drink, not really achieve anything.”
Explaining how he struggled to keep his life on track, Jamie continued: “I had a summer…
“I dropped out of university and I was doing a marketing degree and no interest in any aspect of marketing, and I thought, ‘Well f*** this, I’m going to leave.’
“I got into an interview once and I was explaining what I got up to that summer, and the interviewer goes, ‘So you’re depressed,’ and I was like, ‘Oh s*** yeah.'”
After his sister encouraged him to take part in Channel 4 show Model Behaviour his luck changed.
The Belfast lad quickly rose through the modelling ranks and landed a gig with underwear giant Calvin Klein.
He is now thought to have a net worth of $12million.