Background: In Denmark the boundaries between cannabis as an illicit drug and licit medicine have shifted rapidly in recent years, affecting also policy. However, the vast majority of Danes, who use cannabis as medicine (CaM) continue to rely on the unregulated market for supply. This study explores patterns of use and motives for use of CaM in Denmark. Methods: An anonymous online survey was made available to a convenience sample of users of CaM from July 14, 2018 to November 1, 2018. Participants were recruited through patient organisations, social and public media, and the illegal open cannabis market. Results: Of the final sample ( n = 3,021), a majority were women (62.6%) and the mean age was 49 years. Most had no prescription for CaM (90.9%), a majority had no or limited previous experience with recreational cannabis use (63.9%), and had used CaM for two years or less (65.0%). The most common form of intake was oil (56.8%) followed by smoke (24.0%). CBD oil (65.0%) was used more than hash, pot or skunk (36.2%). Most frequent conditions treated were chronic pain (32.0%), sleep disturbances (27.5%), stress (23.7%), osteoarthritis (22.7%), anxiety (19.6%), and depression (19.6%). Overall, users experienced CaM to be effective in managing somatic and mental health conditions and reported relatively few side-effects. CBD oil only users were more likely to be women, older, have limited recreational experience and have initiated use recently. Conclusions: A new user group has emerged in Denmark that, for the most part, use illegally sourced CaM to treat a broad range of somatic and mental health conditions, often with experienced effect and relatively low level of side-effects. The prevalent use of low-potency CBD oil indicates an interest in effects beyond the high normally associated with cannabis use. More clinical research into the effects and side-effects of CaM is needed to draw the boundaries of the medical utility of cannabis.

Globally, recent studies report increases in ⌬-9-tetrahydrocannabinol (THC) concentration in seized samples of cannabis for human consumption. This is important, because use of cannabis with a high concentration of THC has been linked to a number of adverse health outcomes. The objective of this study was to assess recent changes in the composition of seized cannabis resin in Denmark by (a) examining THC concentration in samples from Danish forensic laboratories from 2000 to 2017 (N ϭ 430) and (b) examining cannabidiol (CBD) concentration and the THC:CBD concentration ratio in samples from the forensic laboratory in Western Denmark from 2008 to 2017 (N ϭ 147). Cannabis resin samples were analyzed using a gas chromatographic analysis with flame ionization detection quantifying the total THC and CBD concentration. Results showed that the THC concentration increased 3-fold from 2000 (mean: 8.3%) to 2017 (mean: 25.3%). Significant increases occurred in all areas of Denmark. After 2011, we found a dramatic increase in cannabis resin samples with high THC concentration and the near disappearance of cannabis resin samples with medium-and low THC concentration. Furthermore, the THC:CBD concentration ratio increased significantly from 1.4 in 2008 to 4.4 in 2017. Whereas THC concentration increased, CBD concentration remained stable at ϳ6%. In conclusion, the THC concentration of cannabis resin, and THC:CBD concentration ratio, have increased dramatically in Denmark, potentially leading to higher risk of harm to users. Policymakers, treatment professionals, and educators should be aware of this change. Public Health SignificanceBased on seized cannabis resin samples from 2000 to 2017, we observe a threefold increase in THC concentration and a rise in THC:CBD concentration ratio, suggesting that cannabis users may be exposed to higher doses of THC, which may carry a greater risk. Observed trends are strikingly similar to trends reported in France, suggesting that the emergence of new, resin products with higher THC concentration has widely penetrated European markets, including Scandinavia. Policymakers, treatment professionals, and educators should be aware of this change.

Background The use of cannabis as medicine (CaM) both prescribed and non-prescribed has increased markedly in the last decade, mirrored in a global shift in cannabis policy towards a more permissive stance. There is some evidence that cannabis functions as a substitute for prescription drugs, particularly opioids; however, more knowledge is needed on the motives of substitution users, their patterns of use, and perceived effects of substitution use. Aims To explore who substitutes prescription drugs with cannabis, the type of prescription drugs substituted and the type of cannabis used, and the impact that substitution with cannabis has on prescription drug use as well as the motives for substitution in terms of experienced effects and side effects. Methods A self-selected convenience sample was recruited through social media, public media, and patient organizations to take part in an anonymous online survey. Inclusion criteria were 18 years or older and use of cannabis (prescribed or non-prescribed) with a medical purpose. Results The final sample included 2.841 respondents of which the majority (91%) used non-prescribed cannabis, and more than half (54.6%) had used CaM with the purpose of replacing a prescribed drug. Compared to non-substitution users, substitution users were more likely to be women and to use CaM in the treatment of chronic pain and other somatic conditions. Pain medication (67.2%), antidepressants (24.5%), and arthritis medication (20.7%) were the most common types of drugs replaced with CaM. Among substitution users, 38.1% reported termination of prescription drug use, and 45.9% a substantial decrease in prescription drug use. The most frequent type of cannabis used as a substitute was CBD-oil (65.2%), followed by ‘hash, pot or skunk’ (36.6%). More than half (65.8%) found CaM much more effective compared to prescription drugs, and 85.5% that the side effects associated with prescription drug use were much worse compared to use of CaM. Conclusion CaM is frequently used as a substitute for prescription drugs, particularly opioids. More research is needed on the long-term consequences of use of CaM, including the impact from low and high THC cannabis products on specific somatic and mental health conditions.

Background: Beyond the legal use of medical cannabis in Denmark for selected patient groups, a large unregulated use of medicinal (non-prescribed) cannabis occurs. However, little is known about the paths to becoming a medicinal cannabis user and the role that previous recreational experience plays in this process. Aim: Inspired by Becker’s social learning approach to becoming a cannabis user, this study explores sources of inspiration for medicinal cannabis use, the social control factors related to use, and the relevance of recreational experience (RE) with cannabis. Methods: An anonymous survey was made available online to a convenience sample of 2,281 adults (≥18 years) who self-medicate with non-prescribed cannabis. Logistic regression analysis compared users with no RE (46.1%) to users with occasional RE (27.4%) and regular RE (26.5%) in terms of user characteristics, initiation of medicinal use, and experiences with social control factors. Results: Compared to users with RE, users with no RE were significantly more likely to be women, older, more frequent users, and to treat somatic conditions and use low potency CBD-oil. Users with no RE were more likely to rely on social networks for information on medicinal cannabis, use online sources for supply, and find supply stable. Moreover, users with no RE were less likely to keep use secret and find use problematic. Also, when medicinal use develops on a gradual transition from recreational use it is associated with increased odds of treating mental health conditions and with use of smoking as form of intake. Conclusion: The heterogeneity among medicinal cannabis users in Denmark, in terms of demographics, motives for use, and patterns of use, is related to the level of previous recreational experience and to whether medicinal use developed on a gradual transition from recreational use.