They all had their own way of dealing with the grief, but they were initially united in alcohol.
The band were left distraught when Gately died suddenly from an undiagnosed heart condition five years ago aged 33, and they subsequently underwent their 'worst' ever tour.
Mikey Graham said: "When he died we were contractually obliged to go on tour. We were grieving hugely and unfortunately the therapy we turned to on that tour was alcohol which was totally the wrong thing to do."
Ronan added: "It's the worst tour we've ever done. Alcohol stayed with us for quite some time even after the tour. It became a habit."
Thankfully the quartet eventually found healthier ways to cope and adjust to their loss.
Keith Duffy said: "We were using alcohol to numb the pain. I was drinking way too much, upsetting the people I love most and having awful nightmares so I went for bereavement counselling. I talked about my grief and the whole drinking problem and I gave up drinking for the whole of 2011. Saying your problems out loud helps you resolve your issues."
Mikey added "I read a lot of self-help books but I don't think it cured me," while Ronan admitted: "I've had counselling over the years and it's been wonderful."
Shane Lynch meanwhile said: "I fixed myself. My mind is very strong but everyone is different..."
The full interview is available via OK! Magazine