"<< Background >>During the first quarter of 2021, UNAD, in cooperation with member entities of the European Civil Society Forum on Drugs and the European Civil Society Forum on HIV, conducted a European study to identify training needs among professionals in the European addiction sector. 727 professionals from 24 countries participated in the study, whose main results were: 66.57% requested training in ""Non-substance addictions"" and 63% in ""Addictions in adolescents and young people"". These two training areas were already included in the first phase of ""Learn Addiction"" (www.learnaddiction.eu). 47.73% requested training in ""ChemSex"". At that time, there was no open and high-quality training on ChemSex for addiction professionals. This was the reason we decided to develop this project.<< Objectives >>In this context, in order to address the training needs identified among professionals in the European addiction sector, we carried out this project with the aim of producing the first open, multilingual online course for addiction professionals on ChemSex.<< Implementation >>First, we developed the English version of the online ChemSex course. Once the initial development was completed, we organised a testing phase to assess whether the course content was effective in providing European addiction professionals with the required knowledge, skills, and competencies. The testing took place simultaneously in six countries (Spain, Slovenia, Portugal, Czech Republic, the Netherlands, and Germany). Thirty addiction professionals participated in the testing, five from each country. Following the testing, based on the results and feedback from the testers, we defined and implemented the necessary improvements to the online course. Once we had the improved final English version of the ChemSex online course, we translated and published it in seven languages (English, Spanish, Slovenian, Portuguese, Czech, Dutch, and German) on www.learnaddiction.eu. Lastly, we implemented an ambitious dissemination plan to ensure that over 1,500 European addiction professionals began the online course before the project's completion.<< Results >>The main outcome of the project was the first open, multilingual online course on ChemSex for addiction professionals. The course is available in seven languages (English, Spanish, Slovenian, Portuguese, Czech, Dutch, and German) at www.learnaddiction.eu.The course has been well received among addiction professionals. Evidence of this is that over 1,500 professionals started the course before the project's completion. This number will continue to grow, as all participating entities have committed to further promoting and disseminating the online ChemSex course even after the project's end."
