Speaking to New magazine, the 30-year-old said that she feels "amazing" since turning her life around.
Ahead of the launch of the second series of her fly-on-the-wall show this Wednesday, she told the magazine: "Well, after the first series a lot of people have been coming up to me saying, 'I've watched your show and it's inspired me. You've been going through what I've been through and if you can get through it then so can I'. And it's cheaper than therapy. I love the show, we have a lot of fun with it."
She continued: "I watched [the first series of] Kerry Katona: Coming Clean the other day because I was feeling a little bit down. I thought, 'Bloody hell, look how far you've come, Kez'. It's like therapy for me to realise how lucky I am and when I watch it back I think, 'God, was that really you? It doesn't even look like you'. My speech, everything is completely different."
On life without drugs, she added: "Well, I was never an addict, I was more of an abuser, so I'm not struggling at all. I feel amazing. It was a dark period in my life that I will never go back to."
Last week, Katona admitted that she is still upset by press reports which focus on her weight.
Kerry Katona: The Next Chapter airs on Wednesday at 9pm on ITV2.
> Kerry Katona admits 12-hour drinking session