Hatton, who retired in July, was demolished inside just two rounds by Pacquiao in Las Vegas in May 2009, a fierce battering which caused his life to spiral out of control in a battle with drink and drugs.
“I was so down, I was crying and breaking out and contemplating suicide,” Hatton told the BBC.
“I was going deeper and deeper into depression. I was going out and having a few drinks. The worst thing you can do with depression is add alcohol to it.
“I needed something to get my backside into gear and pull my finger out. Sometimes you have to hit rock bottom to think, ‘Blimey Ricky, get a grip’.
“Depression is a serious thing and, after my defeat to Manny Pacquiao, I contemplated retirement and didn’t cope with it very well.”
Hatton’s predicament worsened when he fell victim to a newspaper sting in which he was shown taking cocaine before he went into rehabilitation.
“For someone in my position taking drugs once is nothing short of disgraceful,” said the 32-year-old.
“The reason behind my actions and the way I was behaving wasn’t a drink or drugs thing, it was depression. I was so down, I was crying and breaking out and contemplating suicide.
“Half the things I was doing I didn’t even read about in the paper. I can’t even remember the night it happened – that’s what depression does to you.
“I was having blackouts, days on end whether I was drinking or not when I couldn’t remember what had happened in my life.
“I thank the News of the World because who knows where it could have ended up.”