When we talk about major life events in youth mental health, we often think about stressors and crises: bereavement, separation, violence, serious illness. Yet when we ask adolescents and young adults directly which event of the last few years was most important to them, the picture looks quite different.
In our recent study using data from the Zurich Project on the Social Development from Childhood to Adulthood (z‑proso), we took an inductive and bottom‑up approach. At ages 15, 17, 20 and 24, 1,442 young people each answered a single, open‑ended question:
“If you think back over the last years: what was, for you personally, the most important event in your life?”
Across all waves, this resulted in 5,670 short text segments describing “their most important” life events. Instead of pre‑defining events in a checklist, we started from young people’s own words and then used natural language processing (NLP) -based topic modelling to make sense of these narratives at scale.
What did adolescents and young adults report? Mostly positive, “ordinary” milestones
Contrary to the focus of many life‑event checklists, about 83% of the reported events were positive in valence. When young people were asked openly, they most often named ‘normative’, everyday developmental milestones as their most important events.
Using topic modelling, we identified 12 themes that we grouped into five broader domains:
- Education and career development
- Social relationships
- Leisure activities and successes
- Mental health and well‑being
- Other life transitions and independence
The single most frequent topic, accounting for almost half of all events, was school, education and apprenticeships. Young people also often mentioned romantic relationships and friendships, travel and stays abroad, sports and celebrations, and steps toward independence, such as moving into one’s own flat.
Stressful events did appear. There was a distinct topic of stressful life events and loss, including bereavements, serious illness, and accidents, and a topic capturing episodes of poor mental health and personal change. However, these were far from most responses.
Developmental shifts from mid-adolescence to young adulthood
We also saw clear developmental shifts across the decade from mid‑adolescence to young adulthood. In mid‑adolescence (15–17 years), events related to school and friendships were particularly prominent. In the early twenties, work and employment, partnerships, moving out, and starting a family became more frequent, while sports and going out were mentioned less often. These patterns map closely onto developmental theories that emphasise increasing educational, occupational and relational responsibilities across this age period.
How are life events linked to internalising symptoms?
A central question was how these openly reported life events relate to young people’s symptoms of anxiety and depression. We found that adolescents and young adults with higher internalising symptoms showed a different pattern of reported events, controlling for covariates:
- They were more likely to name topics such as romantic relationships and friendships, mental health, development and change, family‑related events, and stressful life events and loss as their most important event.
- They were less likely to report topics such as school, education and apprenticeships, travel and staying abroad, work and employment, and sports.
Put simply, higher anxiety and depression were associated with a greater focus on interpersonal experiences, stressful events and losses, and a lower likelihood of highlighting positive or achievement‑related milestones as the key event in recent years.
A “computational qualitative” approach
Analysing thousands of short, open‑ended responses required methods that go beyond traditional hand‑coding. We therefore used a combination of:
- Topic modelling with BERTopic to identify recurring themes in the text, and
- A large‑language‑model-based classifier to allocate ambiguous or outlier text segments to the most likely topic and to classify emotional valence (positive, negative, ambivalent).
Throughout, we included “humans in the loop”: researchers manually reviewed topics, merged overlapping themes, and corrected misclassified text segments where needed. We describe this as a computational qualitative approach, the questions and data are inductive and open‑ended, while the analytic pipeline is quantitative and scalable, with manual oversight to preserve interpretability. All analytic code is shared openly with the paper, so that other teams can adapt this workflow to their own cohort or clinical datasets.
What does this mean for research, practice and policy?
Rethinking how we study life events
Many widely used life‑event checklists focus primarily on stressors and threats, and often omit the positive, seemingly ‘mundane’ developmental milestones that adolescents themselves highlight as most important. Our findings suggest that this emphasis may give a skewed picture of young people’s lived experience. At the same time, they align well with multisystem models of resilience and recent work on benevolent and protective childhood experiences, which emphasise every day, relational and contextual resources as key supports for healthy development.
Using open‑text questions analysed with natural language processing allows large studies to capture a wider spectrum of youth life events, track how these self‑defined experiences change across adolescence and young adulthood, and examine how mental health symptoms influence which events are seen as “most important,” while integrating young people’s own words alongside standard quantitative measures.
Implications for prevention and care
For practitioners and policy‑makers, several points stand out:
- Youth is not only crisis. Most adolescents and young adults in our sample described positive, normative milestones as the key events in their recent lives. Recognising and supporting these everyday transitions—school and training pathways, friendships, first relationships, travel, steps toward independence—may be just as important as focusing on crises.
- Internalising symptoms change the lens. For young people with higher anxiety and depression symptoms, stressful interpersonal events and losses came to the foreground, and positive, achievement‑related events receded. This underlines the importance of early identification and support, not only to reduce distress but also to prevent a narrowing attribution of how life is experienced.
- Promoting positive experiences as a resource. Interventions and youth policies that create opportunities for positive, personally meaningful experiences—stable educational routes, chances to succeed and feel effective, safe and supportive relationships, access to leisure and travel—may help foster resilience and well‑being, and perhaps buffer the impact of stressors over time.
Looking ahead
Our study is one of the first to use advanced natural language processing to analyse openly reported life events in a large urban cohort from mid‑adolescence to young adulthood. By combining self‑defined events with standardised measures and applying similar methods to other open‑text questions, as for instance young people’s hopes and worries for the future, we can build a richer picture of youth development. Natural language processing more broadly offers behavioural and mental health science a way to turn everyday language into scalable, theory‑relevant measures of psychological constructs, while maintaining rigour and reproducibility. Such approach can help research, services and policy align more closely with what matters in young people’s lives.