Suggest Treatment For Vascular Dementia, Extreme Anxiety And Depression

My mother is 92 yrs. of age. She suffers from vascular dementia. Recently she has become extremely anxious and depressed. Her behavior is beginning to be very anti-social; bordering on hostility. Her physician prescribed .5 mg. of Xanax at bedtime. Her behavior has worsened and she stays up all night and does not make up the sleep during the day. She is on medication for cholesterol and high blood pressure. Some suggestions for better sleep at night, especially.