Harm potential of magic mushroom use: A review

This review (2011) summarizes the literature on physical or psychological dependence, acute and chronic toxicity, the risk for public health, and criminal aspects related to the consumption of magic mushrooms. The authors conclude that the use of magic mushrooms is relatively safe as only few and relatively mild adverse effects have been reported.

Abstract

“In 2007, the Minister of Health of the Netherlands requested the CAM (Coordination point Assessment and Monitoring new drugs) to assess the overall risk of magic mushrooms. The present paper is an updated redraft of the review, written to support the assessment by CAM experts. It summarizes the literature on physical or psychological dependence, acute and chronic toxicity, risk for public health and criminal aspects related to the consumption of magic mushrooms. In the Netherlands, the prevalence of magic mushroom use was declining since 2000 (last year prevalence of 6.3% in 2000 to 2.9% in 2005), and further declined after possession and use became illegal in December 2008. The CAM concluded that the physical and psychological dependence potential of magic mushrooms was low, that acute toxicity was moderate, chronic toxicity low and public health and criminal aspects negligible. The combined use of mushrooms and alcohol and the quality of the setting in which magic mushrooms are used deserve, however, attention. In conclusion, the use of magic mushrooms is relatively safe as only few and relatively mild adverse effects have been reported. The low prevalent but unpredictable provocation of panic attacks and flash-backs remain, however, a point of concern.”

Authors: Jan van Amsterdam, Antoon Opperhuizen & Wim van den Brink

Summary

In 2007, the Minister of Health of the Netherlands requested a review of magic mushrooms. This paper summarizes the literature on magic mushrooms.

1. Introduction

The CAM, an advisory board of experts that provides science-based advises about recreational drugs, assessed the overall risk of magic mushrooms after a fatal accident involving a French girl who allegedly had consumed magic mushrooms before the accident occurred.

2. Methods

The European Monitoring Center for Drugs and Drug Addiction (EMCDDA) reported on hallucinogenic mushrooms in 2010 and two literature reviews in Dutch were available. This report was updated using searches in the Medline database 2000 – 2010.

3. Magic mushrooms products

The present report reviews psilocine and psilocybine containing mushrooms, i.e. magic mushrooms. They are sometimes consumed as chocolate bars containing grounded mushrooms.

Magic mushrooms vary in potency, depending on the species, their origin, growing conditions and age. The recommended dose is between 1 and 3.5 – 5 g of dried mushrooms or 10 – 50 g of fresh mushrooms, but short-term tolerance may develop rapidly to both physical and psychological effects.

Some mushrooms may contain considerable amounts of phenylethylamine, which is a sympathomimetic amine structurally related to amphetamines. Phenylethylamine is not likely to be abused, and is more stable in dried mushrooms than in fresh mushrooms.

4. Availability of magic mushrooms

4.1. Availability in the Netherlands

When magic mushrooms were still legal in the Netherlands, 64% of users aged 18-years and older purchased their mushroom products in smart shops, souvenir shops and via the internet. Since December 2008, however, the use and possession of magic mushrooms has become illegal in the Netherlands.

4.2. Availability in Europe

In 2003, 4-8% of 15-16 year old students reported easy access to magic mushrooms, whereas more than 20% of students reported easy access in the Czech Republic, Ireland, Italy, Poland and the UK.

There is a rapid diffusion of new products and brands in the consumer market, such as the legal magic mushroom Amanita muscaria.

5. Prevalence of use

In the EU, prevalence estimates for use of magic mushrooms are considerably lower than those for cannabis. However, life time prevalence estimates appear to equal those for ecstasy among students aged 15 – 16 years in some countries.

In the Netherlands, the prevalence of magic mushrooms use among young adolescents has decreased since 1997. The prevalence of use among young visitors to Dutch pubs has also decreased.

6. Acute adverse effects

6.1. General side effects

A ‘trip’ usually lasts between 2 and 6 h, with mild adverse effects remaining present for up to 12 h. Subjective effects range from intended feelings of relaxation to delusions.

A recent web-based survey on hallucinogenic drugs among 600 subjects showed that magic mushrooms were considered as beneficial with a relatively low harm potential. However, some users experienced negative effects like restlessness, impaired coordination, anxiety, impaired judgment of time or distance, sense of unreality or depersonalization.

6.2. Bad trips

The experience of a bad trip is often referred to as a ‘bad trip’, and may include severe agitation, confusion, anxiety, impaired concentration and judgment, and acute psychotic episodes. It is speculated that the combined use of magic mushrooms with other psychoactive drugs increases the risk for bad trips.

6.3. Set and setting

Magic mushrooms have a variety of effects, which depend on the set and setting of the user. In later studies, subjects were better prepared and interpersonal support was given during the period of drug action, which led to fewer adverse psychological effects.

31% of volunteers experienced significant fear when treated with 30 mg/70 kg, but no serious psychological adverse effects were reported in a recent meta-analysis.

6.4. Acute physical adverse effects

Psilocybin mushrooms may cause dizziness, nausea, weakness, muscle aching, shivering, abdominal pain and dilation of pupils, but in general, body temperature remains normal. Tachycardia is a common finding in patients intoxicated by Psilocybe mushrooms.

6.5. Documented fatal incidents

Fatal intoxications due to exposure to magic mushrooms are rare, and usually due to the combination of magic mushrooms with other drugs, mostly alcohol. The lethal dose of magic mushrooms for humans is very low, and normally people do not die from a magic mushroom overdose.

A 6-year old child developed hyperthermia and status epilepticus after consuming magic mushrooms, and a 31 year old man died after leaping from a tower block window.

A 33 year old Irish man and a young French girl died after taking magic mushrooms. Their blood contained high levels of psilocybin and cannabis. A 27-year old Frenchman was found dead in an irrigation canal in winter time, a 18-year old male died on Hawaii after consumption of ten magic mushrooms, a young French girl jumped from a building in Amsterdam after consumption of magic mushrooms, and a 20-year old Dutch male died after consumption of magic mushrooms.

6.6. Interaction of magic mushrooms with other drugs

Both psilocine and psilocybine are dimethyltriptamines (DMT’s), which are rapidly metabolized by the enzyme MAO. Alcohol, chocolate, and tobacco use may enhance the trip (and adverse effects!) induced by magic mushrooms.

7. Chronic toxicity

7.1. Flashbacks

Flashbacks are spontaneous recurrences of a previous psilocybin experience, without renewed intake of the drug. They may occur long after having used magic mushrooms, and are most often reported after LSD use.

7.2. Psychosis and other psychiatric diseases

In a series of studies, psilocybin induces a psychotic state that mimics certain aspects of acute and incipient stages of schizophrenia. It is advocated that psychiatric patients and genetically susceptible subjects should fully abstain from the use of any recreational drug.

8. Physical and psychological dependence

The authors could not find any evidence that magic mushrooms can lead to physical or psychological dependence.

9. Public health effects

9.1. Availability of adequate user information

Many young tourists visit the Netherlands to use magic mushrooms, but most incidents occur in foreign tourists. Therefore, retailers from the smart shops provide warnings in English about the use of magic mushrooms.

Magic mushrooms should be taken in small portions, because the aimed effect is delayed due to slow uptake into the blood using this route of dosing. The quality of the information provided by those selling the product varies.

9.2. Emergencies related to the use of magic mushrooms

The reported number of people seeking medical assistance for magic mushrooms intoxication is very low. In the last 5 years, the number of cases has increased considerably to around 30 – 40 calls annually, though this is still relatively low.

In 2005, Amsterdam Municipal Health Service registered 2837 calls for ambulance service assistance related to recreational drug use. Most of the calls referred to ambulance services given to tourists, and most incidents were related to the combined use of magic mushrooms with either alcohol or cannabis.

The Dutch National Forensic Institute investigated 4636 cases of suspected psilocybin use, and found psilocybin in only 4 of them.

10. Public order and safety

Magic mushroom users could behave recklessly and have panic attacks during a ‘bad trip’, which could evoke aggressive behavior. Forensic physicians in Amsterdam registered 30 – 36 lock-ins per year related to magic mushroom intoxications.

11. Criminal involvement

The Dutch National Criminal Intelligence Service found no evidence of public nuisance as a result of sale or use of magic mushrooms. The Dutch National Police Forces confiscated one large mailing of 27 kg magic mushrooms in 2006 – 2007.

12. Conclusion

The use of magic mushrooms rarely leads to physical or psychological dependence, and adverse effects are mild. However, flashbacks and accidents may occur, and require proper surveillance.

The list of fatal accidents and suicides in Section 6.5 is partly based on newspaper articles and will probably not be complete. However, many accidents can be prevented by a supporting setting, such as surveillance by a ‘sober’ person.

A recent study ranked magic mushrooms as the least harmful illicit drug based on dependence potential, acute and chronic adverse health effects, prevalence, social harm and criminality.

Magic mushrooms were considered to have a low risk potential, but the Dutch Minister of Health prohibited the possession, use, production and trafficking of magic mushrooms in December 2008.