On 15 December 2025, Youth-GEMs hosted Science Café #37, bringing together young experts and researchers to discuss progress within the clinical study (WP7) and new insights into gene–environment interactions (WP5). As always, the session began with icebreakers, setting an open and collaborative tone.

Clinical Study Update

Renzo Abregú-Crespo (Psychologist researcher at Hospital General Universitario Gregorio Marañón in Madrid) was invited to update the young experts on the clinical study. The clinical study aims to recruit young people aged 12–24 who have had their first contact with public mental health services. The goal is to better understand how mental health evolves over time and to evaluate whether treatments are effective. Participants are invited for follow-up assessments at five time points: 3, 6, 12, 18, and 24 months. During these visits, they complete clinical interviews, questionnaires, and cognitive assessments (such as attention, memory, and processing speed). Biological samples are collected via blood draw or saliva. Currently, six countries are actively recruiting: Croatia, Estonia, Spain, Finland, the Netherlands, and Serbia. Around 400 participants have been included so far, with the overall goal of reaching 1,000 young people. Some countries are experiencing more challenges in recruiting participants compared to other sites.

Young Experts’ Input on Recruitment and Retention

Renzo invited young experts to reflect on how to make the study more appealing and how to encourage participants to remain involved throughout the follow-up period. Several suggestions emerged:

• Financial compensation remains important.
• Emphasizing the meaningful impact of contributing to a large European research project could increase motivation.
• Offering certificates or recognition that participants could add to their CVs.
• Exploring possibilities such as study credits (where applicable).
• Providing something valuable at each follow-up visit, such as mental health resources, blogs, or personalized insights where ethically feasible.
• Clearly communicating why continued participation and follow-up assessments are essential for the study’s success.

Questions were also raised about whether participants could receive feedback on certain assessments (e.g., cognitive results), though researchers noted that this requires careful consideration given the research (not therapeutic) context. An additional suggestion was to provide a QR code for individuals who decline participation, allowing them to share what would make the study more appealing. This could offer valuable insight into recruitment barriers.

The discussion highlighted the importance of transparency, recognition, and a personal approach when engaging young participants in long-term research.

Gene–Environment Interactions

The second part of the session focused on understanding how genes and environmental factors interact in shaping mental health. Angelo Arias Magnasco (PhD candidate at Maastricht University) explained a lot about these interactions. Although humans share 99.9% of their DNA, the remaining 0.1% contributes to individual differences. These differences arise from genetic variants. Some traits are influenced by a single gene (monogenic), while most (like height or mental health vulnerability) are polygenic, meaning they are influenced by many genes.

Genome-Wide Association Studies (GWAS) help researchers identify genetic regions (loci) associated with certain traits or conditions. However, genes alone do not determine outcomes. Environmental exposures also play a major role. Through an interactive discussion, young experts identified environmental factors they associate with mental health, including: stress, family and social networks, financial situation, pollution, green space, sunlight exposure, walkability and surroundings and access to treatment. Angelo introduced the concept of the Exposome Score (ES), which reflects the cumulative effect of environmental exposures, and discussed how genes and environment interact (GxE). The diathesis–stress model was used as an example: genetic vulnerability can be seen as partially filling a glass, while life stressors add more. When the glass overflows, symptoms may develop. Importantly, risk does not equal certainty: environmental conditions and protective factors matter greatly.

Ethical and Practical Reflections

Young experts raised important questions about genetic information:

• Would people want to know their genetic susceptibility to certain conditions?
• Is more information always better?
• How should privacy and data security be safeguarded?
• Would genetic feedback be helpful only if lifestyle changes are possible?

Concerns were expressed about how individuals interpret genetic risk information and about trust in companies offering direct-to-consumer genetic testing. Angelo emphasized that genetic risk indicates probability, not destiny, and that context and explanation are crucial.

The session concluded with reflections on resilience research and the importance of positive environmental factors. Young experts were invited to join future WP5 meetings if interested, reinforcing the project’s commitment to meaningful youth involvement.