Dementia is a syndrome characterized by gradually worsening, usually permanent, unlimited cognitive — emotional, intellectual, mental, and subjective — losses.
Delirium vs Dementia
People often confuse delirium with dementia. Delirium follows a fluctuating course and is reversible. Dementia, on the other hand, keeps progressing and is irreversible. Delirium can be thought of as acute brain failure (sudden) and dementia as chronic brain failure (lifelong). People with dementia can also develop delirium — they can get temporary episodes of acute brain failure.
Dementia is diagnosed in a specialist setting, usually by an older-age psychiatrist.