The following tips are provided by the Alzheimer’s Association, the world’s leading voluntary health organization in Alzheimer’s care, support and research.  ©2013 Alzheimer’s Association, reused with permission.

There is no single test or questionnaire to detect depression. For a person to be diagnosed with depression in Alzheimer’s, he or she must have either depressed mood (sad, hopeless, discouraged or tearful) or decreased pleasure in usual activities, along with two or more of the following symptoms for two weeks or longer:

  • Social isolation or withdrawal.
  • Disruption in appetite that is not related to another medical condition.
  • Disruption in sleep.
  • Agitation or slowed behavior.
  • Irritability.
  • Fatigue or loss of energy.
  • Feelings of worthlessness or hopelessness, or inappropriate or excessive guilt.
  • Recurrent thoughts of death, suicide plans or a suicide attempt.

Link: http://www.alz.org/care/alzheimers-dementia-depression.asp#diagnosis