F78 — Other mental retardation

Concept, in one sentence

Intellectual disability is evident, but a specific, identifiable associated impairment (sensory, physical, or severe behavioural) prevents confident grading.

Decisive boundary cues

• A documented, specific confound preventing assessment -> weighs toward F78.
• No assessment attempted and no reason given -> weighs toward F79 instead.
• A grade successfully assigned despite an associated impairment -> weighs toward the relevant F70-F73 grade, not F78.

Duration/course cue

Not duration-based; the decisive factor is why grading was not achieved.

Nearest alternatives

F79, F72, F73

Common mistake

Assigning F78 whenever an associated physical impairment is present, without checking whether it actually confounded assessment.

Retrieval prompt — one-line memory anchor

What specific confound, if any, is documented here as preventing a confident grade?