The singer has been more open about his struggles behind the scenes during his time in the group of late, recently admitting he was crippled by severe bouts of agoraphobia during his late teens as he and his bandmates quickly became household names.
Now Liam, 25, has revealed he would often indulge in a few drinks before hitting the stage during the "Story of My Life" hitmaker's massive tours to mask the mental health issues he had started to develop.
"When you're doing hundreds and hundreds of (concerts) and it's the same 22 songs at the same time every single day, even if you're not happy, you've got to go out there," he tells Men's Health Australia.
"It's almost like putting the Disney costume on before you step up on stage and underneath the Disney costume, I was p**sed quite a lot of the time because there was no other way to get your head around what was going on.
"I mean, it was fun. We had an absolute blast, but there were certain parts of it where it just got a little bit toxic; it's difficult when you have the level of fame that we had in the band."
One Direction, which also featured Harry Styles, Niall Horan, and Louis Tomlinson, went on an indefinite hiatus in 2016 to allow the stars to pursue solo careers, and Liam feels "lucky" to have been able to get "back into a sense of normality."
However, the singer is still dealing with the after effects of having allowed the boyband's managers to control so much of their lives.
"I still struggle with it (feeling in control) now," he explains. "I really struggle to say no because I don't like to let people down. It's in my nature."
And although Liam is the first to recognise the pitfalls of his time with One Direction, he prefers to treat the experiences as learning curves instead of regrets.
"I've got a lot of things wrong in my time, but they were also the moments that I've learned the most about myself," he shares. "The moments to do with fear, patience, intelligence, all those different things."
Stepping out as a solo artist isn't the only big change Liam has had to adapt to in recent years - he also became a father to a son named Bear, now two, with his ex-girlfriend Cheryl Cole.