What are secondary dementias compared to regular ones?

A secondary dementia: Is one that is caused by an underlying health problem such as cardiovascular disease causing a vascular dementia or alcohol causing an alcoholic demential. A primary dementia is an illness that begins in the brain itself, such as alzheimer's dementia.

Can reverse?: Secondary dementia is most commonly due to an adverse medication reaction, but may be seen with vitamin deficiencies, toxins, thyoid issues, metabolic imbalances, active infections, etc. The point is, can reverse these, but cannot cure alzheimer's disease.