Citation

Casajuana Kögel C, Balcells-Olivero MM, López-Pelayo H, Miquel L, Teixidó L, Colom J, Nutt DJ, Rehm J, Gual A. Drug Alcohol Depend. 2017; 176: 109-116.

Affiliation

Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Grup de Recerca en Adiccions Clínic (GRAC), Addictions Unit, Department of Psychiatry, Clinical Institute of Neuroscience, Hospital Clínic, Universitat de Barcelona, Red de Trastornos Adictivos (RTA), Spain.

Copyright

(Copyright © 2017, Elsevier Publishing)

DOI

10.1016/j.drugalcdep.2017.03.010

PMID

28531767

Abstract

OBJECTIVE: Reliable data on cannabis quantities is required to improve assessment of cannabis consumption for epidemiological analysis and clinical assessment, consequently a Standard Joint Unit (SJU) based on quantity of 9-Tetrahydrocannabinol (9-THC) has been established.

METHODOLOGY: Naturalistic study of a convenience sample recruited from February 2015-June 2016 in universities, leisure spaces, mental health services and cannabis clubs in Barcelona. Adults, reporting cannabis use in the last 60 days, without cognitive impairment or language barriers, answered a questionnaire on cannabis use and were asked to donate a joint to further determine their 9-THC and Cannabidiol (CBD) content.

RESULTS: 492 participants donated 315 valid joints. Donators were on average 29 years old, mostly men (77%), single (75%), with at least secondary studies (73%) and in active employment (63%). Marijuana joints (N=232) contained a median of 6.56mg of 9-THC (Interquartile range-IQR=10,22) and 0.02mg of CBD (IQR=0.02); hashish joints (N=83) a median of 7.94mg of 9-THC (IQR=10,61) and 3.24mg of CBD (IQR=3.21). Participants rolled 4 joints per gram of cannabis and paid 5€ per gram (median values).

CONCLUSION: Consistent 9-THC-content in joints lead to a SJU of 7mg of 9-THC, the integer number closest to the median values shared by both cannabis types. Independently if marijuana or hashish, 1 SJU = 1 joint = 0.25 g of cannabis = 7 mg of 9-THC. For CBD, only hashish SJU contained relevant levels. Similarly to the Standard Drink Unit for alcohol, the SJU is useful for clinical, epidemiological and research purposes.

Copyright © 2017. Published by Elsevier B.V.

Language: en

Keywords

9-Tetrahydrocannabinol; Cannabis; Metrics; Prevention; Standard unit