Zac Efron is one of Hollywood's most sought actors and has lived most of his life in the public eye. Although being such a successful star comes with many perks and rewards, there is undoubtedly a negative side to it, and the 26 year-old stud definitely had his fair share of both sides.

Zac Efron
Efron has had to deal with alcohol and drug abuse issues

Efron entered a rehabilitation facility twice last year after his partying lifestyle was getting out of control, he received treatment for drug and alcohol abuse once these issues worsened when filming Seth Rogen's 'Bad Neighbours' in April 2013, as he began to frequently miss scheduled shooting days.

More: Zac Efron Admits Opening Up About Drug Abuse Was A "Weight Off My Chest"

Efron has rarely spoke of his substance abuse issues over the past year, but he recently offered a candid explanation as to why he turned to drugs and alcohol when speaking with British adventurer Bear Grylls on an episode of 'Running Wild with Bear Grylls.'

"The challenging part was never the work - that was never it," he said on the NBC show. "It was sort of the in-between work. The social aspects outside it - I mean, everywhere you go to a certain extent there is press in some form."

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"I mean whether you're going out to an event, where you're supposed to be out with friends, there will be press there, if you are leaving your house to go to the grocery store, there will be press there," he continued. "It can be everywhere, and it's, you know, it can be confusing. You spend a lot of time in your house going crazy, you know pretty soon you need a social lubricant."

Zac Efron
Efron spoke of his substance abuse sturggles while appearing on NBC's 'Running Wild with Bear Grylls'

Zac added, "Once I needed that, it became to go anywhere. It was getting to the point where I was caring less about the work and waiting more for the weekend you know what I mean, where I couldn't wait to go out. You know, and sort of let loose and have fun."

Upon realizing this, after finishing a stint at rehab Efron joined Alcoholics Anonymous, and this past spring he spoke about this experience very highly, telling The Hollywood Reporter, "I think it's changed my life. I'm much more comfortable in my own skin. Things are so much easier now." However he did admit, "It's a never-ending struggle."