Ms Methven recalled one day where King handed her his phone so he wouldn't have to speak to anyone.
"He made me take his phone, that's how much it affected him, saying 'I don't want to talk to the world, I don't want anyone talking to me'," she said.
"But it got him back reading again ... and I'm fortunate enough that I understand and am home and can take care of him."
She'd also been caught out by the fact they'd just moved into their new South Auckland home and King had taken to painting the house in order to keep his demons at bay.
Previously the signs were more recognisable: negativity, short temper and apathy.
"But he was like a crazed man when we moved in here, painting the exterior of the house immediately, within days of moving in he was outside and he was frantic and I was like, 'who is this man and what is this?'" Ms Methven said.
King told the Herald he felt a sense of relief revealing his latest battle on Facebook on Thursday night, but is annoyed with himself that he didn't recognise what was happening to him.
He said he had been overwhelmed by the reaction from friends, family and social media followers. "I really didn't expect all of that."
He said he would be a hypocrite if he didn't talk about his experience given he spoke to schools, community groups and corporate organisations about dealing with depression.
"For too long in this world we tell kids what to do but we don't actually do it ourselves, so in the last few years me and the Key to Life Trust have taken the view 'don't tell me, show me'. It seems to have resonated, especially with younger people.
"Most young people have in this world never met a flawed adult in their life ... then they come across a flawed adult and they see life through different eyes."
King has often spoken publicly about his tumultuous personal life.
He began his latest post by stating: "I have a confession to make. For the last few months I have been struggling with depression."
He wrote how it left him in a "vicious cycle" of "frustration, and anger, followed by regret, remorse and inevitably back to anger".
Speaking about his latest battle was almost therapeutic, he said
"It's healing for me because there's a lot of people out there wondering about my behaviour and the thing is when you are depressed and become negative and don't return phone calls and become really short with people, that all needs an explanation."
Where to get help
Mental Health Foundation: (09) 623 4812
Lifeline: 0800 543 354
Depression Helpline: 0800 111 757
Healthline: 0800 611 116