The Jersey Shore star - real name Mike Sorrentino - revealed in a statement released on Wednesday (March 21) that he voluntarily entered a programme to address the issue.
Sorrentino said: "I want to set the record straight. I have voluntarily taken steps to get control of a prescription medication problem I had due to exhaustion.
"I have spent the past several weeks getting treatment for this problem and recuperating from my work and appearance schedule. I appreciate my fans' support, and love you guys."
A spokesperson for Sorrentino had previously denied reports that the reality TV personality had entered rehab, but confirmed earlier this week that Sorrentino had spent "the past several weeks at an undisclosed location for much-needed rest and recuperation".
An MTV spokesperson said in a statement: "We have no comment about Mike, but fully expect and are looking forward to the entire cast returning for a sixth season."
TMZ has claimed that Sorrentino is being treated at Cirque Lodge in Utah.
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