UPDATE (September 19, 2013):

TMZ now reports that Zac completed not one, but two separate stints in a treatment facility in the past year, making the former High School Musical star essentially the James Bond of overcoming substance abuse undetected. The website claims that Zac's most recent stint in rehab following production of Seth Rogen's Neighbors this spring was treatment for a relapse, following the actor's initial attempt to kick his addictions to cocaine and molly in March.

A source for TMZ claims that, in addition to the usual intense pressure that goes along with early stardom, Zac's substance abuse issues were triggered by insecurities surrounding his career and his love life, in addition to a contentious relationship with his parents. Of course, no story of struggle and redemption would be complete without a villain, so there's also talk of the perfectly-coiffed golden boy hanging out with a so-called "bad crowd." Regardless of what prompted his use, we're just glad to he's on the mend.

UPDATE (September 17, 2013, 6:53 p.m. ET)

On the heels of a report that Zac Efron completed a rehabilitation program five months ago for an unspecified substance abuse issue, TMZ now reports that Zac's problem was not alcohol but drugs — specifically cocaine and molly (the street term for pure MDMA, or Ecstasy). A source tells the website that Zac was "a no-show on a number of days," during filming of the upcoming 2014 release Neighbors, costarring Seth Rogen.

A source associated with the film says, "it was common knowledge [Zac] was struggling with cocaine." Maybe on-set, but if it's true, it's certainly news to Zac's fans. When TMZ contacted Zac's rep, she responded, "Don't think we'll be making a comment." Well, whether Zac has been in rehab for any substance — legal or illegal — may be cause for speculation, but the important takeaway is that he's doing great these days.

If the rumors are true, Zac wouldn't be the first former Disney star to need a little help, but fortunately, he also wouldn't be the first one to bounce back. Demi Lovato also went quietly to treatment for a host of mental issues, including addiction, and her self-awareness paid off, as evidenced by her X Factor gig. Lindsay Lohan's trips to rehab are now infamous, but she seems to be doing pretty great these days. Britney Spears checked herself into a treatment facility after her head-shaving incident, and is doing fantastic now.

We're totally rooting for Zac, and only partially because we still have a crush on him from way back in the High School Musical days. We've missed seeing him around (getting peed on by Nicole Kidman doesn't count) and hope that he and his hot bod stay happy and healthy.

ORIGINAL STORY:

If Zac Efron really went to rehab, as a new report from E! News claims, he did so with such secrecy that no one in the press seemed to know.

Sources tell E! News that Zac completed a rehabilitation program five months ago — and seems to have made a full recovery.

"He's healthy, happy and not drinking," one source tells the site. "He's taking time to focus on working."

The comment that Zac isn't drinking now implies that he was treated for alcoholism, but until we hear the news from the actor or his representatives, that's all just speculation.

On the September 6 premiere of Zac's new film Parkland at the Toronto International Film Festival, the 25-year-old told E! that he's "good, real good."

In the film, Zac plays Jim Carrico, the real-life doctor who was the first to treat President John F. Kennedy at Parkland Memorial Hospital in Dallas after Kennedy was shot. The movie hits theaters on Oct. 4.

Zac — who skyrocketed to fame with the High School Musical franchise — also has two comedies (That Awkward Moment, Neighbors) and one drama (Autobahn) in the pipeline.

And it's a good thing he's staying so busy — we couldn't think of a better way to avoid the media circus a story like this will undoubtedly set off.

Sources: E! News, TMZ

Credit: AlloyDigital Photo: Kristen Stewart Wants Zac Efron? Demi Lovato Talks Relationships & Katy Perry Roars - Clevver Feed
Dan Clarendon is an assistant editor at Wetpaint Entertainment. Follow him on Twitter and Google+!