Have you ever heard of hikikomori?

I bet not. But do you have patients with it?

Almost certainly.

I only just learned about it myself, while browsing the literature for fresh LinkedIn posting material. I almost scrolled right by a new meta-analysis — but then flashed on a trip I'd just taken to Japan.

My first time there. I stayed near Shinjuku station — the busiest train station in the world.

Over 3 million people pass through it daily.

Standing in that crowd, I felt something I didn't expect. Not wonder. Pressure. The density, the noise, the sense that everyone around me was performing competence at full volume.

I could imagine wanting to disappear.

That's hikikomori.

Literally: "pulling inward." First described by Japanese psychiatrist Tamaki Saito in 1998 — and for decades assumed to be a uniquely Japanese problem.

It isn't.

A 2025 meta-analysis of 19 studies and 58,000+ participants found cases across Europe, North America, and beyond. US estimates put prevalence around 2–3%. Roughly 1 in 40 Americans.

The working criteria (Kato, Kanba & Teo, 2020 — no DSM code yet):

▸ Marked social isolation confined to one's home

▸ Lasting at least 6 months

▸ With significant impairment or distress

Severity ranges from occasionally leaving the house to rarely leaving a single room.

Most cases carry a recognizable comorbidity — depression, social anxiety, ASD features. But a meaningful subset doesn't fit any existing diagnosis. They just disappear from clinical view.The truth? Post-COVID, this is harder to spot than ever. Staying home is normalized now. The line between chosen withdrawal and pathological isolation has blurred — and psychiatry hasn't caught up.

Have you encountered patients who fit this pattern — and how did you recognize it?

Share this with a colleague who might be missing it.

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