"I felt really really scared for my son. He's going to kill somebody, that's how I felt at the time. I was scared for what might happen to his future," Oldehaver said.
"I tried to call everybody possible, but I couldn't get through to anyone. I got told to go to the next person or most places said because it was the weekend there was nothing they could do."
Oldehaver tried to get help from three local mental health services and also called a helpline where the operator informed her they could not help unless her son was suicidal.
A spokesperson at one service told her there was nothing they could do, another was closed for the weekend and the third could only treat him if he was there in person.
"Of course, we couldn't physically get him there because he was still saying that he wanted to kill us. I thought it was their job to help us," Oldehaver said.
"I decided 'nobody's listening to us,' so I made a video. I wanted to make sure I had done everything in my power to get my son what he needed."
Oldehaver posted the plea for help video on her Facebook page and it quickly went viral, with thousands of shares, comments and interactions.
It even caught the attention of mental health advocate and 2019 New Zealander of the Year Mike King, who offered to pay to get her son private treatment.
However, Oldehaver stuck to her guns, calling a local service again and demanding a consultation despite being told at first that the wait would be at least a month.
Oldehaver's son is currently staying with an aunty. She believes he is doing okay and he has just started replying to her messages as he waits to see a psychiatrist this week.
Before the knife incident, they'd been waiting to see a mental health specialist as Oldehaver's son was exhibiting "disturbing" signs after discontinuing his medication.
Oldehaver said a paediatrician approved the decision and her son was doing really well after a couple of months without the medication.
This changed after a few months, so they visited their GP who prescribed the old medication, however, this was no longer effective.
They had been waiting for over a month for a consultation about new methods of treatment when Oldehaver got a disturbing visit.
"Some parents of a friend of his came over. They brought a knife that was the size of my forearm. They'd confiscated it off him. He'd been going around town threatening to stab people with it.
"It was very disturbing because for the past month he'd been saying things when people made him angry like 'I'll slit their throat'".
Oldehaver said it was scary having to tell her story in a video to be heard, but the response was overwhelming and she is glad that she did it.
She hopes the professionals can find her son the right medication because "he's a cool kid who's really funny and energetic and amazingly talented at sports".
Oldehaver said she wanted to share her message because there needs to be more support put in place in crisis situations.
'Not being able to get an appointment for weeks and weeks is just ridiculous. These services need to be held accountable," she said.
"There are a lot of people out there who are trying to reach out and the people on the other end of the line are saying 'can you call back on Monday?
"Well, Monday might be too late."
Whanganui District Health Board chief executive Russell Simpson told Stuff there were several departments to provide help in a crisis situation, although it wasn't always clear which one was appropriate, because each situation was different.
The health board's mental health assessment and home treatment team responded to people experiencing an acute mental health crisis 24 hours, seven days a week.
The DHB has been approached for further comment.
