DDx

	Delirium	Dementia	Depression Symptom
Onset	Acute	Insidious	Subacute to Insidious
Time-course	Fluctuating	Progressive	Can be chronic
Consciousness	Variable	Normal	Normal
Sleep	Disturbed	Variable	Variable
Orientation	Impaired	Normal to Impaired	Normal
Perceptual disturbances	Hallucinations	Possible hallucinations	Normal
Thinking	Disorganized	Paucity of content	Usually normal
Speech	Incoherent	Word finding difficulty	Slow to normal
Psychomotor activity	Abnormal	Apraxia to normal	Variable

Delirium → When in doubt, think DELIRIUM
Depression Symptom
Dementia → Think dementia last cuz it is not treatable

Investigation

CAM - Confusion Assessment Tool