<unk>  is a form of cognitive<unk>  that can be distinguished from the "mild" and "moderate" types of<unk> . In the United States, the existence of<unk>  is a condition that triggers benefit payments under most long-term care insurance policies.
Severe cognitive impairment
Mild cognitive impairment
Treatment-resistant depression
Acute behavioural disturbance
Conditions comorbid to autism spectrum disorders
Irregular sleep–wake rhythm
Extrapyramidal symptoms
Recurrent brief depression