"Sitting inside your own head is worse.
"That is the power of the inner critic," Mr King said.
He asked the audience what fueled their addictions. Fear, poverty, and trauma were their answers.
For Mr King, it was his inner critic.
His drive to escape it first turned him into a bully, then it led him to alcohol.
His biggest insecurity and the reason he was bullied was his "big head", but while he was drunk the insult had no effect. Alcohol alleviated his low self esteem.
"I got a break from myself," Mr King said.
"Alcohol is a game changer for people with addictive personalities."
Mr King also suffered from an addiction to cocaine at one point but had been drug-free since April 1, 2007.
What prevented him from seeking help for his issues was the "staunch Kiwi attitude", he said.
"We need to make it okay to talk about our problems."
Mr King said 20 per cent of New Zealanders would have a depressive episode and 80 per cent of those people would not tell anyone.
"Secrets keep you sick," he said.
Parents needed to start talking about their own mistakes and make it easier for kids to come forward with their problems, Mr King said.
"Young people are the solution to the problem."
A video about addiction - created by the Ministry of Health and featuring Mr King - was played for the audience to kick off the speech.
Mr King watched it for the first time alongside everybody else in the room.
In it, he offered a metaphor to explain the damage done by not being able to share your issues.
"What happens when you put a lid on a boiling pot?"