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There is no single cause of depression. Instead, many different factors (physical, psychological and social) are likely to contribute to the development of depression in older adults.

  • Physical factors: Change in brain chemistry, physical illness, genetic factors.
  • Psychological factors: Life events, reaction to a significant illness, loss.
  • Social factors: Isolation, lack of financial support, lack of community support.

There are two distinct categories of people who can develop late-life depression:

Genetics. It’s in the family: We are all genetically vulnerable to something. Our genes can play a role in illnesses such as diabetes, heart disease, and cancer. Mental illness is no different.

Some people are predisposed to develop depression just because it’s in their DNA. It can be triggered by any combination of stressors. An older adult with this history is likely to have experienced depression at other times in their life.

First time in late-life: These patients are a bit of a mystery. From a mental health point of view, they have been healthy their whole lives and never had any previous experience with depression. They have often overcome major life issues like immigration, poverty, divorce, bankruptcy or loss. Then, with or without a significant stressor, they develop late-life depression.


In seniors, depression is caused by one single incident.


Depression in older adults is caused by a combination of multiple contributing factors.

Some medical conditions can trigger depression for the first time in late life:

  • Heart attack
  • Stroke
  • Parkinson’s disease
  • Arthritis
  • Cancer
  • Diabetes
  • Chronic pain
  • Loss of vision
  • Alzheimer’s disease

During an episode of depression certain chemicals in the brain called neurotransmitters may be too low or not functioning properly. Neurotransmitters that may play a role in depression include:

  • Norepinephrine
  • Serotonin
  • Dopamine

Sophisticated brain imaging technology has revealed specific areas of the brain that are impacted by depression. Science also shows that the manner in which the brain heals may differ depending on the individual and the type of treatment they choose - whether anti-depressant or psychotherapy - both are effective, but in different ways.

Today, regardless of the challenges of aging, it is not normal to have to live in a depressed state, and it is unfortunate when people suffer needlessly.

Friends and family play a crucial role in preventing loneliness and ensuring older adults keep up their social contact.

Avoid the risk of developing major depression. Ask for help.

Any healthcare professional can help: A family physician, visiting nurse, physiotherapist or social worker.

Get counselling and/or therapy as soon as possible.

Risk factors for developing late-life depression


There’s no history of depression in my family, so it won’t happen to me.


We are all at risk of becoming depressed given certain medical conditions or unfortunate circumstances such as excessive stress or loss.

Risks for developing depression later in life increase for many reasons. Early life factors, more immediate life events, and the many stressors associated with living a long life – health issues, losing those closest to you – make us vulnerable to episodes of late-life depression.

Common risk factors include:

  • Being female: Depression is more common in women of all ages than it is in men. But the risk is particularly significant for women over 65, who live alone and are in poor physical health. The risk increases with advancing age.
  • Early life loss: A child who loses a parent early in life is at risk for developing depression at any time throughout their lifetime.
  • Family history: Those with a family history of depression have a 40 per cent likelihood of developing depressive illness. Genes, the basic building blocks of life, inherited from our parents, can play a part in the development of illness. If a person carries an abnormal gene or genes, it increases the risk of disease. The person will be more likely to develop illness if other conditions or factors are present.
  • Previous personal history of depression: A person who experienced depression earlier in life is at risk of it happening again. More than half of people who have a previous episode of depression will have it happen again.
  • Activity in the brain (physiological changes): Important chemicals (neurotransmitters) that are active in the cells of the brain have been identified as having a role in depression.
  • Illness: Older people with neurological (brain) illnesses that cause a mental decline, such as stroke and dementia (e.g., Alzheimer’s disease) often also experience depression. Diabetes and heart disease may also lead to depression.
  • History of chronic illness: Older adults who struggle with a chronic illness that prevents them from carrying out the activities of daily living or connecting with social support, can become depressed.
  • Medication(s): Some medications such as those used to treat high blood pressure, steroids (e.g. prednisone), painkillers and tranquilizers have been known to cause depression as a side effect.
  • Late-life loss: Losing a spouse or those closest to you increases the risk of developing depression.
  • Long-term care: Having to move into an institution or long-term care facility increases risk of depression.