A Northland teenager became so psychotic after taking "magic mushrooms" he had to be strapped to a hospital bed by his hands and feet.
The incident has prompted police to issue a warning about the dangers of taking the mushrooms, which have been "popping up all over the place" due to the recent rain and mild temperatures.
Acting Senior Sergeant Peter Masters said the Kerikeri 19-year-old consumed the mushrooms on May 15 and was taken first to Bay of Islands Hospital in Kawakawa, then transferred to Whangarei.
He was "out of control" in hospital and had to be cuffed to the bed by his hands and feet to stop him harming himself or others.
Mr Masters said the mushrooms' active ingredient, psilocybin, was a class A controlled drug with a chemical make-up similar to that of LSD.
Cannabis was by comparison only class C, which illustrated the seriousness of magic mushrooms.
"I don't know why people do it. Why take the risk? You can end up psychotic, with mental health problems for life, or dead."
Over the past few weeks, Far North police had fielded several complaints about people searching for mushrooms in private gardens, including one from a property owner who had called into the Kerikeri station just yesterday.
Mr Masters urged anyone who saw people "fossicking in their gardens" for the fungi to call police immediately.
"We're keen to get on top of this," he said. A Whangarei Hospital spokeswoman said the teenager had been treated and discharged.
John Fountain, a medical toxicologist at Otago University's National Poisons Centre, said an overdose of magic mushrooms could make people "quite unwell" with seizures and toxic syndromes.
The problem with mushrooms was that it was difficult to control the dose: "One day you might get the desired dose, the next you might get a lot more."
Users could also do things while hallucinating that they normally wouldn't, such as trying to fly from a building, but the greatest risk came from picking the wrong kind of mushroom.
The death cap mushroom, for example, looked similar to the untrained eye but could cause severe toxicity and even death.
"There are some very poisonous mushrooms out there. Our advice is to be very cautious and not collect any mushrooms unless you really know what you're doing and are able to correctly identify them."
The centre was fielding one mushroom-related call a day now mushroom season had started.
Ross Bell, executive director of the New Zealand Drug Foundation, said the magic mushrooms were neither addictive nor toxic, but the effects depended on the dose, which was hard to control.
"The risks are around what the hallucination is going to make you do - people can freak out quite a lot - and that you can think you have a magic mushroom, but instead you're ingesting a highly toxic wild mushroom."
Mr Bell advised staying with anyone who was hallucinating and calling an ambulance.
In 2007, heart transplant recipient Te Awhina Hawera, 23, from Hamilton, died after consuming magic mushrooms.
By Peter De Graaf