Dementia caused by emotional trauma

A fellow caregiver asked...

As quadmama has asked: Can dementia be reversed in the elderly who seem to be declining after the loss of a loved one? My Father just passed away from Alzheimer's/dementia after being married to my Mother for over 62 years. Mom is now declining mentally and physically in the last 3 months since his passing. She is confused easily and depressed. Her balance is off and she trips and stumbles a lot. What can be done?