There are a number of psychiatric and neurological changes that can occur with the major neurocognitive disorder (dementia). These include:

• Changes in personality. Preexisting personality traits may be accentuated during the development of dementia. Patients with dementia may become introverted, have paranoid delusions, or be generally hostile to family members and caretakers. Patients with frontal and temporal involvement are likely to have marked personality changes and may be irritable and explosive.
• Hallucinations and delusions. An estimated 20 to 30 percent of patients with dementia (primarily those with Alzheimer’s type) have hallucinations, and 30 to 40 percent have delusions, primarily of a paranoid nature. Physical aggression is common in demented patients who also have psychotic symptoms.
• Mood disorders. Depression and anxiety affect 40 to 50 percent of patients with dementia, although the full syndrome of depressive disorder may be present in only 10 to 20 percent. Patients with dementia also may exhibit pathological laughter or crying with no apparent provocation.
• Neurological Issues. Seizures occur in approximately 10 percent of patients with Alzheimer’s type of dementia and 20 percent of patients with vascular dementia. Patients with vascular dementia may experience headaches, dizziness, faintness, weakness, and sleep disturbances.
• Sundowner syndrome. This condition is characterized by drowsiness, confusion, impaired balance and coordination, and accidental falls.