Misconception Repair Lab

Ignoring duration and course

(or reveal each step yourself below)

1. The tempting shortcut
"This looks severe, so it must be the most serious category — schizophrenia."
2. Stop and think
Before you read on: what is wrong with this reasoning? Try to answer in your own words, then reveal the explanation below.
3. Reveal — why it fails

Severity at a single point in time does not tell you duration or course, and duration/course is exactly what separates F20 from F23 (and shapes the F20/F25 boundary too). A dramatic acute presentation is at least as consistent with F23 as with F20, and sometimes more so.
4. Reveal — the better reasoning rule
- Exact onset date and how many weeks/months symptoms have been present.
- Whether the picture has been stable or has fluctuated rapidly (polymorphic pattern suggests F23).
- Whether recovery is expected/observed within the F23 time window, or whether symptoms are continuing well beyond one month.
- Whether it is simply too early to classify with confidence, in which case 'insufficient information, reassess after observation' is the correct answer.
Corrective example: A person develops sudden, severe delusions and disorganised behaviour over two days following an acute stressor, and the presentation has lasted one week at the time of assessment. Despite the severity, one week does not meet F20's duration threshold, and F23 (or 'insufficient information, follow up required') is the better-supported answer at this stage.

5. Try the transfer case

Apply the better rule above to a fresh case.