The Irish actor told The Late Late Show host Ryan Tubridy that his high tolerance to drugs and alcohol made it difficult for him to know his limits.
"I'd gotten out of control. For years I could indulge in certain things. I had quite a high tolerance for various drugs for years, I thought," he said. 'It accumulated to the point where I couldn't put my foot on the brake anymore."
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The star says he was inspired to seek help so he could be a good father to his now nine-year-old son James, who suffers with Angelman syndrome, a rare genetic disorder characterized by severe intellectual disability, developmental delays and lack of speech.
Colin has since said that his son is “an inspiration” and that he is in awe of what his son is able to accomplish despite his disability.
“James works really hard in life and is a constant source of inspiration to me. I just adore that little man,” he said in a May interview.
The Irish actor has spoken out about his son’s disability and his struggle with addiction in the past, admitting it was difficult to adjust to his new life of sobriety.
"I began to come out of the haze that I was in and had burrowed myself into so deeply," he previously said.
"Basically, I'd been fairly drunk or high since I was 14. I was very drunk and high for 16 years, so it was a tough life change, and I was dying. I'm one of the lucky ones."