---
title: BPSD — Apathy
type: concept
last_updated: 2026-04-25
sources:
  - code/kb_loader/data/clinical/bpsd/apathy.json
status: settled
---

# Apathy

The most common BPSD across AD stages. Distinct from depression — apathy is loss of *motivation*, not low mood.

## Sensor signature

- **Activity:** suppressed across the day; reduced step count and movement variability
- **EDA:** flat — minimal phasic responses
- **Voice:** reduced spontaneous speech, flat prosody (low F0 variability)

## Why it matters

Apathy correlates with faster cognitive decline. It is also the easiest BPSD to miss clinically because patients don't complain.

## Intervention

Structured engagement, music, social contact, scheduled activity prompts. See [Intervention agent](../agents/intervention_agent.md).

KB: [`code/kb_loader/data/clinical/bpsd/apathy.json`](../../code/kb_loader/data/clinical/bpsd/apathy.json). Umbrella: [BPSD](bpsd.md).