What is the difference between Presenile Dementia compared with Amnesia and Delirium?

As far as I can tell, an early sign of all three is short-term memory loss, but when one focuses on the presenile dementia, how does one differentiate between that and the possibility of amnesia or short-term delirium?What is the difference between Presenile Dementia compared with Amnesia and Delirium?
Dementia, which is commonly caused by Alzheimers (But also can be caused by other diseases like Parkinsons, and Head traumas, etc) is usually a permanent Condition. There is many different stages. Pre, Mid , and Late stage.

Amnesia, and Delerium are temporary conditions, and can involve memory loss short term, or long term. They are usually caused by a blow to the head, or often drugs, which is the main cause for delerium, like Hallucinogenics( 'Shrooms) , LSD, etc. These conditions are usually reversible, but in science, nothing is ever concrete, black and white. THere is exceptions for everything. Dementia really is something usually considered organic, resulting from a problem inside your brain, not from outside sources.



(Presenile DEmentia is just another word for Early Alzheimers, or Prealzheimers)