Harry Judd smoked strong skunk cannabis at school.
The 31-year-old singer - who is the drummer in the band McFly alongside Tom Fletcher, Dougie Poynter and Danny Jones - experimented with marijuana when he was at boarding school and he continued to use the drug into his late teens and 20s.
Harry always thought weed was relatively harmless but he believes his drug use contributed to his bouts of anxiety.
Speaking about his anxiety struggles on ITV show 'This Morning' on Tuesday (17.10.17), the 'All About You' hitmaker said: "I had a very happy childhood, I can't for one minute complain. Very, very happy. I joined the band and when I was 17 and I was a confident guy, and everything was great. But it was when I was about 19 when things started to turn for me and I did start to suffer with anxiety."
Revealing when he first tried the drug, he said: "It wasn't actually in school, it was actually in the school holidays. But that's the thing with marijuana you've got different forms of marijuana, and I stumbled across the stronger sort."
And Harry admits his cannabis use increased when he was living with the rest of McFly and he had "no one" around to challenge his actions.
He said: "Then I joined the band and I remember the first time in the band house I was tentatively checking whether they had smoked before. And I remember thinking I had left home, and I have left school and thinking 'I am a free man, I can do what I want.' No one was looking over me. I very quickly felt dependent on skunk. And I remember growing up being told 'You can't get hooked on weed'. But within a month or so, that was it, that was me every night. It was a tough time; things were great, we were number one, selling out tours, and it got to the point where I really start to suffer with anxiety and the thing with anxiety is it creates irrational thoughts. There were times where I struggled to cope with the position I was in."
Harry - who has seven-week-old son Kit and 20-month-old daughter Lola with his wife Izzy - eventually ditched the drug and has revealed he has beaten his anxiety through exercise and he's now never been happier or more in control of his life.
He said: "Thankfully for me, this is not a sob story it has been a very happy outcome and I have had a very happy adult life, but it has had its ups and downs and that is what has inspired me to write the book.
"It was exercise that was the catalyst that helped me cope with these problems."