F23 — Acute and transient psychotic disorders

Concept, in one sentence

A psychotic episode with acute onset (about two weeks or less) and an expected brief course, often following a stressor, regardless of how severe or F20-like the symptoms look during the episode.

Decisive boundary cues

• Acute onset within about two weeks, rapidly shifting picture -> weighs toward F23 over F20.
• Symptoms persisting essentially unchanged beyond one month -> weighs toward F20 over F23.
• Slow-building, narrow, single-theme delusion developing over months -> weighs toward F22 over F23.

Duration/course cue

Onset speed (acute, ~2 weeks or less) plus an expected brief course are the defining features, not a minimum duration.

Nearest alternatives

F20, F22

Common mistake

Classifying a dramatic, severe first presentation as F20 immediately, before duration and course have had a chance to clarify whether it is actually F23.

Retrieval prompt — one-line memory anchor

How quickly did this start, and how long is it expected to, or has it already begun to, resolve?