Q) Hypo or hyperactivity is required to have a diagnosis of delirium?
Conventionally, delirium has been divided into hypo, hyper, or mixed activity types but is not required as a diagnosis per the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5). The five key features described are:
1. Disturbance in attention (reduced ability to direct, focus, sustain, and shift attention) and awareness.
2. The disturbance develops over a short period of time (usually hours to days), represents a change from baseline, and tends to fluctuate during the course of the day.
3. An additional disturbance in cognition (memory deficit, disorientation, language, visuospatial ability, or perception).
4. The disturbances are not better explained by another preexisting, evolving, or established neurocognitive disorder, and do not occur in the context of a severely reduced level of arousal, such as coma.
5. There is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by a medical condition, substance intoxication or withdrawal, or medication side effect.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th ed, APA Press, Washington, DC 2013.