Psychology says looking back at your younger self isn't just nostalgic; a Cornell study found the exercise reduced depression symptoms in young adults

If you're in your 20s and you've been scrolling through old pictures and thinking, "Who was I even back then?" you may be onto something more useful than nostalgia. According to a Cornell University study, ‘Strengthening self-continuity to reduce depressive symptoms and derailment: A multiphasic mixed-methods randomized controlled trial,’ published in the Journal of Consulting and Clinical Psychology, journaling about who you used to be, at different points in your life, helped ease depression in a group of young adults. Researchers screened nearly 260 people online, and 111 who had at least moderate depression symptoms completed a two-week journaling exercise. Two months later, those who had journaled about their identity reported significantly fewer symptoms than a control group.

The paper reports a three-phase design: first, 242 emerging adults completed baseline measures of derailment, self-continuity, and depressive symptoms; then 112 eligible participants were randomized to a derailment-focused journaling exercise or a neutral reflective-writing control. Over the two-week intervention, the journaling group answered five prompts about childhood, middle school, high school, college, and their desired future, and the gains were still evident two months later.

A US-focused reason to care
This is not theoretical. Rates of depression have been rising among American adults under 30 for years. According to Gallup's tracking of U.S. depression rates, 28% of U.S. adults ages 18 to 29 are reportedly depressed in 2026, compared with 13% in 2017, and more than any other age cohort today.


According to Gallup's tracking of U.S. depression rates, 28% of U.S. adults ages 18 to 29 were depressed in 2026, more than the 13% of that age group who were depressed in 2017, and more than any other age cohort today. Therapy waitlists are long, insurance is a pain, and a lot of 20-somethings just want something they can try on their own in the meantime. That’s the gap this study is talking about.

What the researchers actually did
Researchers split the participants into two groups. The control group journaled about mundane things, like going to the grocery store. The experimental group spent two weeks responding to five prompts about their motivations, passions, and goals at various stages of life, from early childhood to college to their desired future, and how each stage influenced their current path. They also recorded their identity at each stage in one word, such as “sapling,” “determined,” or “inquisitive,” and then reflected on those words together.

Two months later, the identity-journaling group was far less depressed, less "derailed" (the researchers' term for the mismatch between who you are now and who you used to be), and more connected to their past selves. The control group had wandered back to its starting point.

Why revisiting your story might help
The idea is based on previous research that suggests people who can tell a coherent story about their own life tend to be more psychologically robust than those whose story feels scattered. As Davis puts it: connecting yourself to yourself, across time, seems to be therapeutic in itself.

The Chronicle notes that the trial was not a tiny classroom exercise: nearly 260 people were screened online, 111 qualified with at least moderate symptoms, and half were assigned to a control condition that wrote about ordinary daily events instead. Participants in the intervention then wrote for two weeks about their motives, passions, and goals across five life stages, and the researchers say the biggest symptom drops came from those whose entries showed more reflective self-evaluation rather than brooding.

It also draws on decades of research into expressive writing. According to an American Psychological Association podcast interview with psychologist James Pennebaker, writing about emotionally meaningful experiences, often called the "Pennebaker paradigm," points to real, if modest, benefits to mental and physical health. The Cornell study adds something more specific: it’s not just writing that matters, but writing that connects your past, present, and future selves into one story.

In Pennebaker’s account, the classic expressive-writing paradigm asks people to write about emotionally significant experiences for several sessions, and the benefits tend to be modest rather than dramatic. The APA interview also emphasizes that the best outcomes usually come when writing is sustained and specific, which fits the Cornell team’s argument that the content of the story, not just the act of writing, is what matters here.

The catch: it's not for everyone
The researchers were careful not to overstate the case, and it is worth repeating this caution here. Nearly a quarter of the identity-journaling group made little or no improvement. As the team reviewed the entries, they found that the most successful participants wrote introspectively, weaving threads of positivity even from difficult chapters, such as a difficult college semester that became a period of self-discovery. The least benefited wrote shorter, negative entries, like a high school audition that left them feeling isolated, a pattern psychologists call “ruminative brooding.”

That distinction is important if you try this yourself. If looking back causes you to re-experience old wounds rather than understand them, this exercise might not be the right tool for you right now, and that's a sign to ease off rather than push through.

Where this fits into your mental health toolkit
This was one study, and the researchers say the exercise could be a supplement to therapy, not a replacement. It has not been tested in all populations or all types of depression. But for young adults already struggling with cost-of-living stress and limited access to affordable care, a free exercise with a measurable benefit two months later could be worth paying attention to.

If you want to give it a go, the concept is simple: write honestly about who you were at various times in your life, and how those versions of you connect to who you’re becoming. Pay attention to how it feels as you go, and ease off if it stirs up more than it settles.