Advancing the science on cannabis concentrates and behavioural health

Abstract

Issues: The Cannabis sativa L. plant contains hundreds of phytocannabinoids, but putatively of highest importance to public health risk is the psychoactive cannabinoid delta-9-tetrahydrocannabinol (THC), which is associated with risk for cannabis use disorder, affective disturbance, cognitive harm and psychomotor impairment. Recently, there has been an increase in the use and availability of concentrated cannabis products (or 'concentrates') that are made by extracting cannabinoids from the plant to form a product with THC concentrations as high as 90-95%. These products are increasingly popular nationwide. The literature on these widely available high potency concentrates is limited and there are many unknowns about their potential harms.

Approach: This review covers the state of the research on cannabis concentrates and behavioural health-related outcomes and makes recommendations for advancing the science with studies focused on accurately testing the risks in relation to critical public and behavioural health questions.

Key findings: Data point to unique behavioural health implications of concentrate use. However, causal, controlled and representative research on the effects of cannabis concentrates is currently limited.

Implications: Future research is needed to explore chronic, acute and developmental effects of concentrates, as well as effects on pulmonary function. We also highlight the need to explore these relationships in diverse populations.

Conclusion: While the literature hints at the potential for these highly potent products to increase cannabis-related behavioural health harms, it is important to carefully design studies that more comprehensively evaluate the impact of concentrates on THC exposure and short- and long-term effects across user groups.

Keywords: cannabis concentrate; delta-9-tetrahydrocannabinol; marijuana; tetrahydrocannabinol.

Conflict of interest statement

Conflict of Interest

The authors have no conflicts of interest.

© 2021 Australasian Professional Society on Alcohol and other Drugs.

Figures

Figure 1.

Extraction, production and administration of cannabis concentrates. In solvent-based extractiona (‘Solvent-based extraction’ box), liquid butane passes through organic plant material and is then either extracted or evaporated from the solution, resulting in a high concentration of THC. Increasingly the cannabis industry is moving towards ‘solventless’ extraction (‘Solventless extraction’ box), in which plant matter is agitated then sifted through various filters with the use of cold water, isolating high potency plant rosins that are then pressed between two heated plates. Concentrates can be administered (‘Modes of administration’ box) orally (sublingual) or via inhalation using a water pipe or vaporiser. aDespite the fact that water is in fact an inorganic solvent, extraction methods that utilise water as opposed to a hydrocarbon solvent are nonetheless referred to as ‘solventless’ by industry standard.