Cannabis, a complex plant: different compounds and different effects on individuals

Dec 2012
Zerrin Atakan

 

Abstract

Cannabis is a complex plant, with major compounds such as delta-9-tetrahydrocannabinol and cannabidiol, which have opposing effects. The discovery of its compounds has led to the further discovery of an important neurotransmitter system called the endocannabinoid system. This system is widely distributed in the brain and in the body, and is considered to be responsible for numerous significant functions.

There has been a recent and consistent worldwide increase in cannabis potency, with increasing associated health concerns. A number of epidemiological research projects have shown links between dose-related cannabis use and an increased risk of development of an enduring psychotic illness.

However, it is also known that not everyone who uses cannabis is affected adversely in the same way. What makes someone more susceptible to its negative effects is not yet known, however there are some emerging vulnerability factors, ranging from certain genes to personality characteristics.

In this article we first provide an overview of the biochemical basis of cannabis research by examining the different effects of the two main compounds of the plant and the endocannabinoid system, and then go on to review available information on the possible factors explaining variation of its effects upon different individuals.

Keywords: Cannabis, delta-9-tetrahydrocannabinol, cannabidiol, tetrahydrocannabivarin, endocannabinoids, individual sensitivity to cannabis

Introduction

Cannabis is a complex plant with over 400 chemical entities of which more than 60 of them are cannabinoid compounds, some of them with opposing effects. Cannabis is also the most widely used illicit drug in the world and its use has been associated with various mental health problems, particularly in the young [Hall and Degenhardt, 2007; Degenhardt et al. 2010]. Despite the links made between its use and the development of mental health problems, it is also known that not everyone who uses it is affected adversely in the same way. In this article we will provide an overview of the different effects of the two main compounds of the plant, as well as its effects upon different sections of the population. Before presenting the available evidence in the literature on the reasons for the varying effects of cannabis in different individuals, we will first review the present knowledge on the biochemistry of the cannabis plant and the endocannabinoid system.

 

Conclusion

During the last decade, endocannabinoid research has been one of the fastest growing fields in psychopharmacology, opening ways to discover new medicines for a wide variety of health problems, ranging from metabolic disorders, to glaucoma and schizophrenia.

The distribution of the endocannabinoid system in the brain is interesting as the very same brain areas are also implicated in psychoses, particularly in schizophrenia. Furthermore, complex and intricate involvement of this system with other neurotransmitters such as dopamine, GABA and glutamatergic systems may have implications for the development of a psychotic illness.

Naturally, due to the recent and constant increase in the availability of higher THC content variants of cannabis around the world, there have been increasing concerns about the health risks, particularly for young people. However, cannabis affects people differently and therefore it is important to understand what makes someone more at risk and how they differ compared with those who do not develop psychotic illness. Here we have provided an overview of the available information on the risk factors which may make an individual more at risk, such as predisposition to psychosis, schizotypal personality and certain susceptibility genes.

Finding groups who are vulnerable is particularly important so that they can be targeted for early preventative and therapeutic interventions. Such a search would also lead to the discovery of the biochemical mechanisms involved in cannabis and endocannabinoid research and ultimately to a better understanding of how the brain and the body functions.