By Carol Combs, MSW, Oxford’s Memory Care Program Coordinator

At times, the symptoms of dementia, delirium and depression overlap and occur simultaneously. It is important to recognize the differences in order to seek the appropriate treatment.

Dementia is a disturbance of memory, Depression is a disturbance of mood, and Delirium is a disturbance of awareness. To further explain.

  • Dementia is a gradual and progressive decline in mental processing ability that affects short term memory, communication, language, judgement, reasoning and abstract thinking. It will eventually affect long term memory and the ability to perform familiar tasks. Sometimes there are changes in mood and behavior. There is a slow, chronic progression and it is irreversible.
  • Depression is a biologically based illness that affects a person’s thoughts, feelings, behavior and mood. Symptoms are present on most days for at least two weeks and are out of the ordinary for that individual. Symptoms include tearful or sad feelings, weight changes, loss of interest in usual activities, trouble sleeping, indecisiveness, feelings of worthlessness and low self- esteem.   It is usually reversible with treatment and may be worse in the morning. A history of depression in young adulthood is a risk factor for late life depression. Approximately 20% of persons over the age of 65 suffer from depression.
  • Delirium is characterized by a sudden, acute and fluctuating onset of confusion, disturbance in attention, disorganized thinking and/or decline in level of consciousness. Delirium is most often caused by underlying infection such as a urinary tract infection, medication toxicity or other illness. It is usually reversible with treatment and is often worse at night.

Individuals with dementia are susceptible to both delirium and depression. Unfortunately, it can go unrecognized because many symptoms are shared and may be dismissed as the natural progression of the dementia.

Unlike the subtle decline with dementia, the confusion of delirium fluctuates over the day, at times dramatically. The hallmark separating delirium from underlying dementia is inattention. The individual simply cannot focus on one idea or task.

Depression is more prevalent in the early stages of dementia and the symptoms can mimic the cognitive impairment of delirium and dementia. Apathy, social withdrawal, loss of interest in activities and impaired thinking are symptoms shared by dementia and depression. The person with dementia may not be able to articulate feelings associated with depression, while the depressed person may be willing and able to talk about it.

To detect depression in dementia, it is important to read the nonverbal cues and body language, as well as discussion with those who are familiar with the person’s usual mood and behavior. While the cognitive decline with dementia cannot be reversed, depression can be treated and may improve the quality of life for the individual.

Whether you suspect dementia, depression or delirium the first step is to seek a medical evaluation and assessment.

  1. Review possible medication errors, reactions or contradictions.
  2. Investigate a referral for supportive counseling.
  3. Create a calm soothing environment.
  4. Encourage a balanced diet, exercise and hydration.
  5. Vaccinate against influenza and pneumonia.

Oxford HealthCare offers numerous home care programs that can provide you the help, support and relief you need, so you can enjoy time with your loved one and continue to care for them at home.   If you have questions, our Memory Care Program Coordinator will be happy to assist you.


American Psychiatric Association (2000) Diagnostic and Statistical manual of Mental Disorders

Susan K Schultz MD, Associate Professor of Psychiatry, University of Iowa