Nostalgia Isn't Sentimental. It's Medicine.
Nostalgia was once classified as a disease. Swiss soldiers were discharged for it. Now research shows it boosts optimism, reduces anxiety, and gives your brain a reason to keep going.
In the 17th century, Swiss physicians coined the term "nostalgia" from the Greek nostos (homecoming) and algos (pain). It was a medical diagnosis. Swiss mercenaries fighting abroad kept getting sick. Fever, insomnia, irregular heartbeat. The doctors decided the cause was homesickness so severe it became a physical illness.
Soldiers were discharged for it. Some were reportedly threatened with execution to stop the outbreak.
For the next 300 years, nostalgia was treated as a disorder. A weakness. Something to overcome.
That changed around 2006, when a research group at the University of Southampton decided to actually study what nostalgia does to the brain. They found the opposite of what everyone assumed.
What Nostalgia Actually Does
Constantine Sedikides and Tim Wildschut have been running the Southampton nostalgia research group for nearly two decades now. Their findings are consistent and kind of remarkable.
Nostalgia increases optimism. Nostalgic reflection raises self-esteem, and the self-esteem boost raises optimism about the future. Not "living in the past." Using the past to fuel confidence about what's ahead. Recalling meaningful personal memories reminds you that your life has had good things in it. Which makes you believe it can have good things in it again.
Nostalgia counteracts loneliness. The memories people gravitate toward during nostalgia are almost always social. Moments with friends, family, partners. Revisiting those memories reduces feelings of isolation even when you're alone. The brain processes the recalled social connection similarly to actual social contact.
Nostalgia provides existential grounding. A 2025 study in Personality and Social Psychology Bulletin found that nostalgia enhances meaning in life through ritual engagement. When people engage in ritualized reflection on past experiences (anniversaries, traditions, deliberate reminiscing) the nostalgia provides a sense of continuity and purpose.
Nostalgia reduces social anxiety. A 2024 study found that socially anxious individuals who engaged in nostalgic recollection showed reduced interpersonal competence deficits. The nostalgia didn't cure the anxiety. But it compensated for the cognitive costs. The self-doubt, the awkwardness, the feeling of not knowing what to say. Nostalgic memories provided a counterexample. You have connected with people before. You can do it again.
The Self-Humanity Finding
A 2025 study found that nostalgia helps people internalize qualities regarded as "uniquely human" (moral reasoning, personal agency, emotional complexity) and integrate them into their self-concept.
Nostalgia doesn't just make you feel warm. It makes you feel more human. It reconnects you with the parts of yourself that feel most real and most yours.
Think about what the nostalgic memories actually are. They're the birthday where everyone showed up. The road trip where everything went wrong and it was perfect anyway. The conversation at 2 AM where someone said the exact right thing. These aren't random memories. They're the moments when life felt most alive, most connected, most meaningful.
When you recall them, you're not just remembering an event. You're reminding yourself of who you are when things are working.
The Caveat
Nostalgia isn't uniformly positive. A 2024 review in the British Journal of Social Psychology found that nostalgia rooted in unhealthy behaviors (drinking, smoking, drug use) can reinforce those behaviors. If your most vivid memories of connection and belonging happened while using, nostalgia for those moments can be a relapse trigger.
I know this one personally. Some of my strongest nostalgic memories involve people and situations that weren't good for me. The warmth is real. The pull is real. But the memory is selective. It gives you the feeling without the full context.
Nostalgia amplifies what it's pointed at. Point it at healthy memories and it heals. Point it at unhealthy ones and it reinforces. The mechanism is the same either way. The direction matters.
Why the Brain Does This
The current theory is that nostalgia is an evolved psychological mechanism for self-continuity. It connects your past self to your present self. It says: you were that person then, you are this person now, and there's a thread connecting the two.
This matters more than it sounds. One of the core features of depression is disconnection from your own life. Things that used to matter don't. Relationships that felt real feel distant. The person you were last year feels like a stranger.
Nostalgia pushes back against that. It provides felt evidence (not just intellectual) that your life has coherence. That you've had moments of genuine connection and meaning. That the thread is still there even when you can't feel it right now.
This is probably why people reach for nostalgia during difficult times. Not because they're weak or stuck in the past. Because their brain is running an adaptive program. When the present is threatening, access the archive for evidence that things have been meaningful before and can be again.
What I Do With This
I keep a notes file on my phone where I write down specific good memories when they happen. Not a journal. Just moments. "Saturday morning, coffee on the porch, [friend's name] called and we talked for an hour about nothing." "The night I finished the first version of the site and it actually worked."
Not because I'm sentimental. Because the research is clear. When I need them later, the more specific and vivid the memory, the more effectively nostalgia does its job. Generic warmth is nice. A specific moment with specific people in a specific place is medicine.
The Swiss soldiers weren't weak. They were running the right program. They just needed to go home.
Sources
- Sedikides, C. et al. "Nostalgia as a Resource for Psychological Health and Well-Being." Current Directions in Psychological Science (2015)
- Yin et al. "Nostalgia, Ritual Engagement, and Meaning in Life." PSPB (2025)
- Dai et al. "Nostalgia and Social Anxiety." SPPS (2024)
- Nostalgia and self-humanity. Journal of Positive Psychology (2025)
- Wohl et al. "The utility of nostalgia for unhealthy populations." BJSP (2024)
- Back to the future: Nostalgia increases optimism. ScienceDaily (2013)
Part of the Rewrite series. Previous: You've Never Used Your Full Memory. Next: Without Memory, There Is No You.
