Depression and dementia may be mistaken for each other. Patients with AD often have depressive symptoms. Nearly half of elderly patients with reversible dementia and depression will develop irreversible dementia within 5 years.
“The most important diagnostic tools are the informant interview and office-based clinical assessment. Physicians should interview both the patient and a reliable informant and inquire into the patient's current condition, medical and medication history, patterns of alcohol use, and living arrangements,” Small et al., 1997.