Michael Douglas feared he would lose his son as his drug addiction spiralled out of control.
Michael and Cameron Douglas
The 'Fatal Attraction' star admitted he wasn't convinced 40-year-old Cameron - who was jailed in 2010 on drug-related offences - would survive his abuse of cocaine and heroin.
In an interview with People magazine, Michael said: "There were moments when hope dwindled... and then it's just a train out of the station. Life became a series of crises. I thought I was going to lose him."
Cameron took cocaine on a daily basis at the height of his addiction and suffered seizures as a result of the drug consumption, despite the best attempts of Michael and Cameron's mother, Diandra Luker.
Cameron, an actor who starred in 'National Lampoon's Adam and Eve', eventually knew his addiction would either kill him or send him behind bars.
He said: "When you get that far down the rabbit hole, there are a couple of options: there's prison and then there's death."
Cameron explained that drugs had a "stranglehold" on his life and that he was unable to stop even though he hated what had happened to him.
He said: "I hated the wreckage I saw in my life because of drugs, but I just couldn't stop.
"It's the sneaky power, the stranglehold that addiction has when you're in the throes of it."
Two-time Oscar-winner Michael previously admitted that Cameron's prison sentence could be a "fresh start." He also assumed blame for Cameron's situation for "being a bad father."
Cameron was released from prison in 2016 and later welcomed daughter Lua Izzy Douglas with his yoga instructor girlfriend, Vivienne Thibes, 41.
He has released a memoir, 'Long Way Home', and hopes to help other addicts "seek help - and maybe save a life."
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