'Incoherent' synthetic drug user filmed screaming, writhing in front of Auckland schoolkids

A man has been filmed having an intense psychotic episode outside an Auckland primary school, prompted by what is believed to have been a cocktail of synthetic cannabis and bath salts.

In footage taken at a bus stop outside New Lynn Primary School in west Auckland on Thursday morning, the man can be seen screaming and kicking while under the influence.

Shade McClellan, who filmed the video, told RadioLIVE's Ryan Bridge that there were originally "three or four guys" high on synthetic drugs at the bus stop - but they left when the one in the video started screaming.

"They were all on it as well. One person fortunately enough was able to tell us they'd just taken synthetic drugs, along with bath salts," he said.

"It wasn't nice, eh. I wouldn't want anyone to see that, let alone because they were sitting outside a primary school. The kids that were watching it, I felt sorry for them.

"It was very scary - not a nice thing to watch."

Mr McClennan explained that he tried to make contact with the man to ask if he was alright - but said "it was like he was in another realm".

"He was just screaming to us that someone was trying to kill him. We tried to give him some water and stuff but he wasn't doing much so we called the ambulance," he said.

He said a number of schoolkids from New Lynn Primary saw and heard the man, but were quickly whisked away by teachers - but he said his tortured screams will have left a mark.

"I keep playing that video clip and hearing that guy scream - it keeps giving me quivers to hear a grown man scream like that and be incoherent," Mr McClennan said.

"To not know where he is and what's going on - wow. It's an eye-opener."

Mr McClennan said that his experience this morning drives home the message that synthetic cannabis is more dangerous than the real thing.

"It's cheaper, it's available, you're not gonna get in trouble for smoking it," he said.

Drug researcher Dr Chris Wilkins told The AM Show on Wednesday that the effects of synthetic cannabis are different and "much more potent" than the real thing.

Health authorities have confirmed eight deaths from synthetic drug use in New Zealand in the last month.