Charlie Sheen is owning up to his struggles with addiction.
In a preview from his upcoming interview with Dr. Oz -- which will air on Monday, Jan. 18 -- the 50-year-old actor shares that his bouts with "manic behavior" have occurred due to "substance abuse and drinking."
"It doesn’t really happen when I’m not doing that," Sheen admits. "It has never really reared its head."
WATCH: Charlie Sheen Looks to Dr. Oz for Emotional Support in HIV Battle
"I’ve been described or diagnosed by enough people. I guess at some point you have to take a look at it if it keeps walking like a duck," he adds. "And I’m not opposed to investigating that aspect of myself."
Sheen also says that he would "consider" treatment for mania if it was made available to him, insisting it would help him decide how to get on with his life.
"It would be to be once and for all find out, and then I’d kind of say, 'Thanks for being right,' or, 'Thanks for assessing me correctly.' Or I can finally say, 'You know, enough, you’re wrong.' At least I would have the data to go from."
WATCH: Charlie Sheen Reveals He's HIV Positive
Last November, the former Two and a Half Men star revealed on the Today show that he is HIV positive. Now, Sheen is bringing his struggles to The Dr. Oz Show to try and piece his life back together.
"This disease chose the wrong person," the actor says in a clip that was released last week.
"Like all of us, Charlie is looking for answers in his own life and making peace with what he's going through," Dr. Oz told ET. "That's a difficult voyage."
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The physician also explained that Sheen's health will be an ongoing battle.
"There were some things he needed to keep focusing on -- the alcohol being a good example," Dr. Oz said. "But the treatment for HIV is so effective now that you have a normal life expectancy. You can live a pretty normal life because of that."
Watch the video below.