Chemsex Drugs on the Rise

A Longitudinal Analysis of the Swiss HIV Cohort Study From 2007 to 2017

B Hampel; K Kusejko; RD Kouyos; J Böni; M Flepp; M Stöckle; A Conen; C Béguelin; P Künzler-Heule; D Nicca; AJ Schmidt; H Nguyen; J Delaloye; M Rougemont; E Bernasconi; A Rauch; HF Günthard; DL Braun; J Fehr


HIV Medicine. 2020;21(4):228-239. 

In This Article


This study investigated longitudinal population-based data on recreational drug use among people diagnosed with HIV infection in Switzerland. The time trend for drug use was analysed longitudinally over an 11-year period to elucidate patterns of use of different substances over time as well as different dynamics of drug use when comparing MSM and non-MSM. In addition, we compared potential risk factors for drug use between participants who reported drug use at least once in these 11 years and participants who never reported drug use. When MSM and non-MSM were analysed separately, we found a large disparity in recreational drug use over time between the two groups: for MSM, there was a significant increase in overall drug consumption, whereas for non-MSM there was a decrease. This increase remained significant when less harmful illicit drugs were excluded. The most relevant finding is the 12-fold increase in methamphetamine use and the > 3-fold increase in GHB/GBL use. Unfortunately, the SHCS questionnaire does not ask about the setting in which a substance is consumed. However, we observed a significant association between the consumption of these recreational drugs and indicators for risky sexual behaviour, namely condomless anal sex with occasional partners and a high prevalence of HCV infection and syphilis. These findings indicate that the chemsex trend has reached Switzerland, and is most prevalent in the region of Zurich.

Our study shows a strong association between depression and the use of all analysed substances. It is well known that depression can lead to a greater tendency to take more sexual risks.[21] However, our study did not address the complexity of the interaction between depression and other sexual risks, as many important questions, such as internalized homophobia or alcohol misuse, were not included in our analysis.

The chemsex scene is difficult to study and probably underestimated by health care professionals and authorities. The difficulties in collecting data on sexualized drug use are well known.[22] With the exceptions of the heroin epidemic of the 1980s and 1990s, which took place mostly in public spaces,[23] and the rise of XTC/MDMA in the 1990s in the club scene,[24,25] chemsex drugs are usually consumed in a private setting and obtained differently from other drugs, for example via geosocial networking apps.[1] This might be the reason why our data on methamphetamine substantially differ from the results of the analysis performed by the FOPH, which did not focus on the HIV-diagnosed or MSM population.[4] It might also be that people who consume chemsex drugs do not attend the health care facilties where interviews were carried out by the FOPH for their study. Another difficulty when studying the chemsex phenomenon is the potential participant reservation regarding sharing such sensitive personal information in view of possible perceived shaming or unsolicited moralizing by the health care professional. This might explain the difference between the results of the patient interview from the SHCS and the online questionnaire from the Swiss HCVree trial. Based on this observation, all data presented above can be considered as a lower bound for drug use among SHCS patients. Furthermore, considering the numerous colloquial terms for the drugs recorded in the SHCS, often with incorrect spelling (see Table A1, Appendix 1), we assume that knowledge about these substances is rather limited among Swiss health care professionals.

As our study is the first to provide longitudinal data on recreational drug use among MSM living with HIV, our results are difficult to compare with those of other studies in the field. However, the study suggests that the use of chemsex drugs among MSM living with HIV seems to be lower in Switzerland than in the UK.[5] This is consistent with the 2010 EMIS survey among HIV-positive and HIV-negative MSM.[3] In addition, our study shows almost no use of mephedrone among HIV-positive MSM in Switzerland. The reason why mephedrone did not become as popular in Switzerland as in the UK has, to the best of our knowledge, never been studied. We see the overall decline in recreational drug use among non-MSM as further evidence of the success of preventative measures, such as safe injection sites and drug substitution programmes, for those who have previously used intravenous heroin.[12,26]

This study has several strengths and some limitations. Most importantly, we were able to analyse prospective data on recreational drug use amongst people diagnosed with HIV infection from an 11-year period and identify possible risk factors associated with this behaviour. The SHCS includes the majority of the HIV-diagnosed Swiss population and is therefore highly representative for this population. As a limitation, our data quality check revealed that drug consumption in the study population is probably considerably underestimated. Furthermore, we do not have information about the setting in which these drugs were consumed. Also, in view of the long study period of 11 years, we did not include multi-drug use when analysing the associated risk factors. Another limitation is that we only had information about people diagnosed with HIV infection and thus it is unclear whether this trend is also seen among HIV-seronegative MSM to the same extent. This information will be crucial to furthering our understanding of the contribution of the phenomenon of chemsex to the ongoing high numbers of new HIV diagnoses among MSM.[12]

Our findings call for action and have several implications for daily practice. First, we recommend that questionnaires on recreational drug use need to be adapted to account for these new trends. For example, we suggest that standardized data collection is used for all recreational drugs on these forms instead of free text data entry. Secondly, we believe that health care professionals working with MSM and other people at risk must be aware of the latest developments related to chemsex in order to ensure expert knowledge about these substances. In addition, these health care professionals should be trained in communication skills to be able to recognize and address problematic drug use and its related health issues and provide low-threshold support. Thirdly, new preventive strategies need to be developed. As the increase in the use of chemsex drugs is mainly seen among the MSM population in certain hot spots, such as in Zürich, prevention programmes should be located in these regions and should be adapted to the specific needs of the MSM population. In addition to creating awareness of the psychological risks that accompany these drugs, such programmes must also involve harm reduction for the prevention of infectious diseases.

In conclusion, our study identified a significant increase in the use of chemsex drugs, in particular methamphetamine and GHB/GBL, among MSM diagnosed with HIV infection in Switzerland and a strong association of this use with coinfections and depression. In light of these findings, more studies in this field are needed to better understand the relationship between sexual behaviour, drug consumption and depression in order to inform successful harm reduction strategies. This further understanding will not only help our patients and potentially decrease numbers of other STIs, including viral hepatitis C, but will also be crucial to our understanding of the current drivers in the ongoing HIV epidemic.