Not knowing what comes next can feel like its own kind of stress. A new study suggests that even a short, self-guided online lesson can help young adults handle that uneasy feeling and report fewer symptoms of anxiety and depression. Why does the unknown feel so loud?
The training took about 20 to 30 minutes to finish, and the benefits were still showing up a month later. The study was published online December 15, 2025, after co-author Yasmin Hasan and colleagues tested it as a simple way to support mental health amid constant curveballs.
Key finding
In the study, a single-session online program designed to change how people think about uncertainty led to bigger mental health gains than two comparison groups. Participants reported lower anxiety and depression symptoms one month after the session, and uncertainty tolerance rose too. The researchers say it could be delivered widely online at no cost.
Those improvements were tied to one central shift. People became more tolerant of uncertainty, meaning they felt less threatened when outcomes were unclear. The results suggest that change was not just a side effect, it was the main pathway to feeling better.
The longer view was more mixed, which is common in mental health research. Mood improvements can fade as daily stress returns, even if the underlying skill sticks around. That is why some experts think short follow-ups could matter.
Why this matters
Young adulthood is packed with unknowns, and not the fun kind. Think about waiting to hear back from a job, a college program, or even a friend who left you on read. When the answer is missing, your brain can fill in the worst-case story.
The study arrived during a period of pandemic fallout, instability, and housing pressure that can make the future feel shaky. Associate Professor Susanne Schweizer from UNSW Sydney said “young people today are coming of age amid great climate, economic, social, and health uncertainty,” and the team argues that this constant backdrop can fuel rising distress.
This research also points to a broader idea in psychology. Some risk factors show up across many conditions, not just one diagnosis. Intolerance of uncertainty is one of those “transdiagnostic” factors, meaning it can raise the odds of several mental health problems at once.
Understanding uncertainty intolerance
Intolerance of uncertainty sounds technical, but it is easy to recognize. It is the feeling that not knowing is unacceptable, and that you must get certainty right now. For many people, that feeling quickly turns into worry, overthinking, or replaying the same fears.
That cycle can make everyday life feel louder and draining. If you constantly scan for threats, you may struggle to focus in class, fall asleep, or enjoy a weekend that should be relaxing. Over time, that kind of nonstop alertness can feed both anxiety and low mood.
A 2023 meta-analysis, which combines results from many trials, found that treatments that lower intolerance of uncertainty often go hand in hand with lower anxiety. That helps explain why this small online lesson might work.
Inside the training
The program was built around a simple reframing. It encouraged participants to see uncertainty as less threatening and to treat coping as a skill that can get stronger with practice. It also tackled worry and rumination, the mental loops that keep dragging you back to the same scary “what if.”
One tool in the session was the STAR strategy, which stands for Stop, Accept, and Rethink. In practical terms, that means pausing when your mind starts spiraling, noticing the uncertainty without fighting it, and then challenging the scary story you are telling yourself. It is not magic, but it is a concrete way to interrupt the habit of doom-scrolling your own thoughts.
A second module was included so the researchers could compare approaches. That psychoeducation session covered general well-being topics like emotion regulation, cognitive biases, meaning common thinking shortcuts, plus social connection and healthy habits. The gap between the two programs helped show what was special about targeting uncertainty itself.
How it was tested
The study enrolled 259 participants ages 18 to 24 and divided them into three groups. About 103 people took the uncertainty-focused lesson, 106 took the general well-being lesson, and 50 got no training. Everyone filled out the same questionnaires at multiple points, including right after training, one week later, one month later, and three months later.
This was a randomized controlled trial, meaning people were assigned by chance to the two training modules so the results would be easier to compare. The no-training group took the same check-ins without getting any lesson, which helped the team spot what might have happened naturally over time. In other words, it made the comparison fairer.
Single-session tools are getting attention partly because they fit real life. A 2017 meta-analysis that pooled data from dozens of randomized studies found that one-time interventions can produce small-to-moderate benefits for some youth mental health problems, though they are not a replacement for longer care.
What comes next
No one is claiming a half-hour module can replace therapy for people in severe distress. The study’s authors stressed that low-cost, scalable tools like this can support prevention, but they are not substitutes for person-to-person care when symptoms are serious. That nuance matters.
The next challenge is keeping the mood benefits from slipping away. First author Sarah Daniels, now doing thesis research at the University of Cambridge, says the core skill may last, but short “booster” sessions could help maintain the mental health gains over time. It is a simple idea, but it needs testing.
Future work may also test versions tailored to specific high-uncertainty moments, like pregnancy or waiting for medical test results. If those studies hold up, quick online “micro-interventions” could become one more tool for young people navigating a changing world.
The main study has been published in Psychological Medicine.
