(Selena Gomez, Creative Commons)

Gomez's reps told People that the singer's time in rehab was "not for substance abuse." 

Similar to her reasoning for canceling her Australian tour, it seems that Gomez's decision to check into rehab may have been motivated by her need to simply take a break and spend some time focusing on herself. 

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Nevertheless, rumors are swirling of the pop star battling a possible drug problem.

A source for Radar Online, which first broke this story, said that prior to entering rehab, Gomez was leading a life characterized by regular partying. The site goes on to report that Gomez had begun experimenting with drugs, specifically marijuana and prescription medications. 

According TMZ, Gomez is holding Justin Bieber and his friends responsible for exposing her to such substances.

While there reamins some ambiguity surrounding what exactly landed Gomez in rehab, the news has certainly come as a shock to her fans. 

Reach Executive Producer Jacqueline Giordano here.