The evidence is solid: purpose predicts survival. Social integration predicts survival. The capacity to imagine a future worth inhabiting is a biological variable, as real as blood pressure or telomere length. Viktor Frankl understood this in the camps. Epidemiology confirmed it in cohorts.

But we never ask the harder question in longevity science: what happens when the horizon disappears entirely?

We measure progress in years added. We're silent on what those years contain. I've seen researchers get excited about extending median lifespan by fifteen years without once considering that these interventions might be delivered to people who've lost the cognitive architecture to find meaning in next Tuesday, let alone next century.

Depression in the elderly isn't a side effect of aging—it's the logical response to a world that stopped needing them. Purpose isn't static; it's relational. It emerges from tension, from stakes, from knowing time is finite and unspent. Remove the finiteness and you don't automatically get more meaning. You might just get more longing.

This isn't an argument against extending healthspan. It's an argument for admitting that meaning deprivation might be the only senescence we can't drug our way out of.

The question I keep coming back to: if we succeed in decoupling lifespan from biological decay, will we have built a world where people actually want to live? Or will we have simply extended the sentence?

We fund molecule screens. We fund epigenetic clocks. I haven't seen a single longevity RFA asking whether our interventions assume a psychological substrate that may not survive the very decades we're trying to create.

The field that solves aging should also ask: what are we solving it for?