Which criterion does ICD-11 criteria lack?

• A. They require functional deterioration
• B. They require 6 months duration
• C. They do not require functional deterioration
• D. They require a 2-year duration

Answer: (C)

The key idea is that ICD-11 does not require loss of function in daily life as a mandatory part of its diagnostic criteria. In ICD-11, the diagnosis is based on evidence of cognitive decline in one or more domains, demonstrated by objective testing or clinical history, but functional deterioration (how daily activities are affected) is not a required criterion across these criteria. This means a cognitive deficit can meet ICD-11 criteria even if independence in daily tasks is still preserved or only mildly affected, especially in earlier or milder presentations. Functional impairment may still be clinically important for staging or prognosis, but it isn’t a formal prerequisite for diagnosis under ICD-11, which is why the statement that they do not require functional deterioration is the correct one.