We're still stunned over the tragic news that Robin Williams took his life at his home in Northern California on Monday, and while his wife and daughter have released statements on his passing, the actor himself had been quite candid over the years about his battles with both depression and substance abuse.

In September of 2013, Williams appeared on The Daily Show with Jon Stewart to promote his new show The Crazy Ones, and he opened up about his troubles. "The only thing that was wired was me -- I was on everything but skates," Williams joked when referencing his days on the hit show Mork and Mindy. "I went to rehab in wine country just to keep my options open."

When asked what pushed him into a relapse when he was filming The Big White in Alaska in 2003, he stated:
    "I think there's a higher power and there's also a lower power And the same lower power goes you know, 'You need this. Come on now.' [When] I relapsed, I was up in Alaska and all of the sudden, I had been sober for 20 years and ... I walked into a store and saw a little bottle of Jack Daniels and went 'Ah, I'll be fine, I'll be ok.' The moment I had the first sip it was like, 'Rahhhh Welcome back *sshole.'

    A week later I was walking down the street with like, ten little bottles of Jack Daniels in my pockets, [and] I sounded like a f*cking wind chime. I got down so quick, I went right to blackouts. And it's a misnomer, they call it blackouts, [but] it's not -- it's like sleepwalking with activities. It's your brain going, 'We're gonna do stuff you're not gonna know!'"

On getting back on track, Williams added, "The main operative word is fear, the fear is there and you're trying to overcome it. If you can deal with the fear, and then realize that some of it is real and some of it isn't, and then come through that, you get deeper."

Williams also spoke about his struggle with a non-clinical form of manic depression during an interview with Terry Gross on the Fresh Air NPR radio show in 2006. "Do I perform sometimes in a manic style? Yes," the Oscar winner said. "Am I manic all the time? No. Do I get sad? Oh yeah. Does it hit me hard? Oh yeah." When asked specifically if he had a diagnosis of clinical depression, Williams said he did not. "No clinical depression, no. No. I get bummed, like I think a lot of us do at certain times," he said. "You look at the world and go, 'Whoa.' Other moments you look and go, 'Oh, things are okay.'"

When Williams spoke to Marc Maron during a 2010 WTF podcast, he even admitted that he had considered suicide while sitting alone in a hotel room with a bottle of Jack Daniels. Williams explained that his "conscious brain" told his drunk brain to "put the suicide over here in the discussion area" until he was sober. That same year, Williams chatted with Britain's Guardian newspaper, and he explained that his relapse was due to "fearfulness and anxiety." He told the publication, "It's just literally being afraid. And you think, 'Oh, this will ease the fear.' And it doesn't. It's just a general all-round argh ... For that first week you lie to yourself, and tell yourself you can stop. And then your body kicks back and says, 'no, stop later.' You feel warm and kind of wonderful ... And then the next thing you know, it's a problem, and you're isolated."

Williams was found dead in his home in Tiburon, California on Monday afternoon, and the Marin County Sheriff's department said in a statement, "At this time, [we] suspect the death may be a suicide due to asphyxia, but a comprehensive investigation must be completed before a final determination is made." Williams' rep confirmed the news and added, "This is a tragic and sudden loss. The family respectfully asks for their privacy as they grieve during this very difficult time."