Fred Nyberg: We need to increase the research on cannabis

2022-01-13

Studies of the medical effects of cannabis are growing in scope, still we lack sufficient knowledge. Therefore, all discussions about legalisation and decriminalisation must be preceded by genuine and extensive research, states Fred Nyberg, senior professor at Uppsala University.

Fred Nyberg, senior professor at Uppsala University
Fred Nyberg, senior professor at Uppsala University

In a recent interview in SVT Vetenskapens Värld, I was asked why cannabis research has not reached further, despite the knowledge that this drug can be used for medical purposes. And yes, it is true that cannabis, like other products from the world of plants, has through the ages been used to provide relief from various disease symptoms. On the other hand, cannabis is also well known for its intoxicating and addictive effects, and Swedish research on cannabis has mainly focused on addiction, dependence and negative effects on health, rather than its presumptive medical effects.

A search in the Pubmed database generates more than 300 articles related to Swedish research on cannabis published during the last 50 years. Half of these were published during the last five years. The early research mainly focused on how the substance can be metabolised and measured in urine samples - among others by researchers at Uppsala University's Faculty of Pharmacy. This research also investigated epidemiological aspects and the drug's effects on mental health.

There are several relevant answers to why insufficient resources have been allocated to research on the medical potential of cannabis. One central aspect is the drug's connection to abuse and criminality.

In the 1960s, the use of cannabis appeared among mods and hippies. Sweden was influenced by youth movements in the US and the rest of the Western world. In the US, marijuana smoking increased and culminated following the 1969 Woodstock Festival. In Sweden, the use reached a peak during 1971-72. The increase led to police efforts and increased penalties for sales. Among politicians, an increased concern was noted, among other reasons because research confirmed the – earlier mentioned – risks to mental health. During the 1980s, cannabis smoking was also assumed to lead to the use of other narcotics, and was included when all use of narcotics was criminalised in 1988.

Cannabis contains almost 500 different substances, of which almost 80 are psychoactive. Although it was known that cannabis has medical effects - including through the active ingredients tetra-hydrocannabinol (THC) and cannabidiol CBD - research in the 1990s focused mainly on the epidemiological, sociological and psychological aspects of cannabis abuse. Only after the discovery of the body-specific (endogenous) cannabinoid system, interest aroused in research on the medical potential of cannabis, especially in the USA but not in Sweden.

Continued concern among politicians and authorities provided little motivation for Swedish researchers to initiate medical studies in the area. From a political point of view, caution as well as the general attitude towards addiction persisted. Among many, knowledge and acceptance to regard substance dependence as a disease was eluded, thus hesitation against methadone based substitution treatment continued.

This perspective was radically re-evaluated at the time of the Swedish Government's Mobilisation against narcotic drugs (MOB). Support was now provided for both syringe exchange and an expanded methadone program. In 2003, MOB announced extensive funding for drug research, but out of about forty applicants, none had a direct focus on cannabis or its medical aspects.

Internationally however, especially in the US, research began on the medical effects of cannabis. In the 1990s, new discoveries led to the description of a body-specific cannabinoid system. In the western world, intensive research were initiated aiming to produce synthetic substances for the development of drug candidates for a number of neurological disease states.

Cannabis, smoked or inhaled, as with marijuana, hardly meet the requirements on a safe medicine set by Sweden, the USA and most other countries. Continued clinical studies of cannabis are needed, a fact that worries US health experts and researchers, but not the politicians who have promoted the legalisation that is now a fact in half of the country's states.

American research on cannabis led to the development of a large number of synthetic substances that act similar to THC but so far the use of these compounds is limited. A partially successful result was obtained in an attempt to produce a pure CBD preparation: The THC-free Epidiolex®, which has been approved by US and EU authorities for severe epilepsy among children. However, the preparation is associated with side effects, and has not yet undergone complete clinical trials, thus not meeting Swedish requirements. To do this, more studies, motivated researchers and sufficient funding is required.

There are also several answers to the question why Sweden has a different approach to cannabis than USA and Germany. Sweden is strict on medicines being as safe as possible and to, unlike some US companies, ensure that adverts for drugs or medical health products is factual. Sweden also has a tradition of social responsibility and to target harm reduction efforts not only at the addict, but also provide support to children and relatives, including prevention, minimised accessibility to drugs and that children should not be in environments where abuse is present.

In terms of providing the drug addicts with optimal help, neither the United States nor Germany deviate from Sweden. What distinguishes Sweden from these countries is that the United States largely looks to economic profit through tax revenues and increased job opportunities for those involved in the production and sale of cannabis. There is also a perception that crime is counteracted through legalisation, as well as that criminal drug dealers should be converted. However, the illegal trade has rather gained an increased customer base, something that is likely linked to the fact that it can sell more attractive products with a higher THC content.

The documentary film shown by SVT Vetenskapens Värld visualises how the use of narcotics has two sides: The medical effects and The risk of harm. Of course, this also applies to cannabis. Undoubtedly, we need more knowledge. Therefore, all discussions of legalisation and decriminalisation must be preceded by genuine and extensive research.

Fred Nyberg, senior professor
U-FOLD, Uppsala University
Fred.Nyberg@farmbio.uu.se

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Photo: Mikael Wallerstedt

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Last modified: 2022-03-31