Zac Efron went to rehab because he ''needed to find himself''.

The 25-year-old actor - who shot to fame in Disney's 'High School Musical' as a teenager - quietly completed a rehab stint earlier this year, thought to be for cocaine and alcohol, and pals close to the star say he realised he needed help and took proactive steps to kick his habit.

A source told UsMagazine.com: ''He realised he needed outside help. He reached out for it and is doing great now.''

It has been said the hunky actor acted ''erratically'' on the set of his raunchy new comedy 'Neighbours' - in which he plays an unruly college student - and his behaviour concerned his friends and family.

The source added: ''His real friends started to worry about him.''

The star sought treatment approximately five months ago and now appears to be back on track with a number of movies due for release over the next year.

A friend of the actor added he is ''doing really great professionally. He's in a good place. He's clean and he's happy.''

Zac walked the red carpet at a premiere for his new thriller 'Parkland' at Toronto International Film Festival on Monday (16.09.13) and told reporters he was doing well.

He said: ''I'm good, real good.''