People with dementia may have moments when they seem perfectly normal. At other times, they may act suspicious, angry, or afraid. They can also become agitated or see things that aren't there. If this happens, try to be understanding. For them, the world can be a very stressful place. But if these changes are sudden or severe, or if they create safety issues, talk to a health care provider. You should also mention any signs of depression. These include withdrawal, loss of interest in activities or food, extreme tiredness, and crying.