He's one of snooker's most charismatic and controversial characters, but depression has at times left him unable to get out of bed for days.
He's also a man who has never been afraid of authority, nor scared of speaking his mind, but, with Mark Allen, the demons associated with his illness are never far away.
Following the break-up of his long-term relationship with Reanne Evans - mother of his nine-year-old daughter Lauren - the Ulsterman was struck down by the crippling affliction.
The world-class cueist also revealed how a friend loaded bins against his window in an attempt to gain access to his home and persuade him to leave his room.
Yet, he's hoping those sort of episodes are now behind him.
"These days it's probably something that I have learned to deal with a bit," he said.
"I still don't enjoy being away from home, I don't enjoy being away from my family and friends, but these things happen.
"You have to sort of put it in the bigger picture. There are a lot of things going on in the world that are worse than what I am going through in my dark times."
Allen's boyhood dream of emulating compatriots Alex Higgins and Dennis Taylor and winning the world snooker title began after he secured the world amateur championship in 2004 and entered the Main Tour in 2005, winning the Jiangsu Classic in China, his first professional title, in 2009.
Currently ranked World No 10, the Antrim native, also known as 'The Pistol', admitted he struggled "mentally, physically and financially" with life as a professional player.
His fall-outs with Barry Hearn, the chairman of snooker's governing body, have become legendary, and at times the 30-year-old appeared to relish being a loner.
The former Belfast Telegraph Young Sports Star of the Year also told World Snooker that being away from family and friends became a problem for him.
"You get into your own bubble and you don't want to get involved with anyone, really," he said.
"A lot of things contributed to it and I'm sure that being a snooker player and being on my own all the time probably triggered it."
Allen, who was speaking a year after the launch of the Mental Health Charter for Sport and Recreation, has been happily married to Kyla McGuigan since May 2013.
He admitted that one of the triggers of his depression in 2011 was the breakdown of his previous relationship with women's world snooker champion Evans (29).
"My relationship that I had been in for a long time had just broken up," he said.
"It was just the normal things people have to deal with, but I didn't deal with them very well by myself.
"It's a bad place to be in, but obviously I had good family and friends around me who pulled me through."
The father-of-one said he now has a better understanding of his own mental health.
"The one thing I have to look out for is when I start turning down plans that I have made," he said.
"The amount of days I would just curl up in bed and watch movies all day, didn't go to practice, didn't socialise with anyone and didn't see my family at all was pretty scary, looking back on it.
"I remember one of my friends that I had spoken to about it and he was the one that I had cancelled on a number of times and obviously it sort of registered to him as to why.
"Then a few times when we made plans after that, when I was in recovery so to speak, I would not answer my phone and kept my front door locked.
"At one stage he put two big bins against the wall on top of each other outside my house and tried to get into my bathroom window, just to try and get me to play golf. It was quite funny because he tried to get in the window and he couldn't get in and the bins fell, so he ended up hanging from my bathroom window upstairs, so I had to help him."