By: Mike Harlos MD, CCFP(PC), FCFP

What is depression?

Depression is a medical condition that affects how a person thinks, feels, and acts. Doctors now know that depression has a biological or chemical basis, so people cannot “shake off” depression on their own. Depression is different from feeling occasionally sad or “blue” in that it can last for weeks, months, or even years. Fortunately, most people find that medication and therapy work well in treating their depression.

Causes of depression

It is not clear what exactly causes depression. One possibility is that a number of factors come together to trigger abnormalities in brain chemicals called neurotransmitters. These changes may affect the way that people feel.

There are many factors that are thought to make people more vulnerable to depression. These are some factors that may come into play in people with life-limiting illnesses:

  • Heredity
    Depression sometimes runs in families, but having a relative with depression does not mean that you will develop it.
  • Medications
    People’s moods can be affected by medications they might be taking. Steroids, for example, may contribute to triggering depression.
  • Stress
    Living with advanced illness is extremely stressful. Someone who normally does not handle stress with ease may be more vulnerable to developing depression.
  • Illness
    There may be a connection between chronic (long-term) illness and depression.

Whatever the cause of depression, it is important to remember that depression is a medical condition and not a sign of weakness in a person’s character.

Signs of depression

People who are depressed usually show a number of symptoms for at least a two-week time period. The first two symptoms in this list are considered core symptoms of depression and must be present for the health care provider to be able to make a diagnosis of depression.

  • Loss of interest in activities
    You no longer take pleasure in things you previously liked to do and almost nothing holds your interest anymore.
  • Depressed mood
    You feel sad, hopeless, or helpless.
  • Changes in weight
    You find your appetite has changed and you are eating much more than usual or much less than usual, resulting in weight changes.
  • Altered sleep patterns
    You are having trouble getting to sleep at night or cannot get back to sleep if you wake up in the early hours of the morning. Or, you find that you are sleeping many more hours than usual, not only at night, but also in the day.
  • Changes in energy
    You feel agitated and restless and have trouble sitting still. Or, you feel slowed down, as if even talking requires too much energy.
  • Fatigue
    You feel tired all of the time and even simple tasks seem exhausting.
  • Poor self-image
    You feel worthless or excessively guilty about things you have done or not done.
  • Trouble concentrating
    You have trouble concentrating, thinking clearly, or making decisions.
  • Thoughts of death
    You wonder if you would be better off dead or have thoughts about killing yourself.

If you, or someone you know, is showing a number of these symptoms, seek medical help. The health care team will want to consider whether depression is the cause.

Depression can affect people of all ages, genders, and ethnic groups. Even people without any identifiable stressors can become depressed. Only a minority of people diagnosed with advanced illness will become depressed, although they will likely experience sadness and strong emotional responses to their circumstances.
See also: Living with Limited Time: Exploring Feelings

Sorting out symptoms

To determine possible causes of depression, the health care team will often ask questions, conduct a physical examination, or order some tests.

Questions from the health care team

The health care team will likely ask about feelings of worthlessness, hopelessness, helplessness, and thoughts about, or wishes for, death. The team will be interested in how long the symptoms have been present, and if they interfere with a person’s social life and the general activities of daily living.

  • When did the sad mood begin? Has the sadness gone away at any time since then?
  • How bad is the sadness?
    • Mild, moderate, severe?
    • How would you rate the sadness on a scale of 0 to 10, with 0 being no sadness and 10 being so bad that it cannot get any worse?
  • Have sad feelings like this happened before?
    • If so, when?
    • Was treatment offered?
    • If so, did the treatment work?
  • Is there any history of depression in the family?
  • Has there been a change in appetite or weight?
  • Have sleep patterns changed?
  • Is there a loss of interest in previously enjoyable activities?
    • Does there no longer seem to be anything worth living for?
  • Is there a loss of energy?
    • A constant feeling of being tired?
  • Is it difficult to concentrate or make decisions?
  • Are there feelings of worthlessness?
    • Are there other negative thoughts, such as feeling like a burden to others?
  • Are there thoughts of suicide?
  • What medications are being taken or have been taken recently?
    • Prescription medications?
    • Over-the-counter medications?
    • Naturopathic and/or herbal treatments?

Physical examination

The health care team is not looking for any one physical sign or symptom in particular, as there is no one sign or symptom that conclusively means someone is depressed. In fact, many physical symptoms that occur in people with life-limiting illnesses, such as fatigue and lack of appetite, can also be symptoms of depression. A general examination can still help in determining if something physical is contributing to the depressed mood. Physical symptoms that may indicate depression include:

  • aches and pains that do not seem to be caused by illness or injury;
  • difficulties with memory. When people have depression, their thought patterns and memory can sometimes be affected. The doctor may ask questions in a physical examination that are meant to test thinking and the ability to remember things.

Illness may also contribute to a depressed mood, so the health care team may want to know details about current and past health history as well.


There is no lab test or x-ray to diagnose depression. However, the health care team may order tests to rule out other medical conditions, which may have symptoms similar to depression. Instead of relying on tests, the health care team must look at all the symptoms to see if there are enough signs of depression to justify a diagnosis.

What you can do

Depression is a medical illness. This means that you cannot “snap out” of a depression on your own. You will need help from your health care provider. You can, however, influence how you cope with depression, and these tips may help:

  • Remember that antidepressant medications take time (two weeks or more) to work. Try not to become discouraged if you don’t feel better immediately.
  • Try not to become isolated – take part in activities or join a support group.
  • Take care of yourself by eating well, getting enough sleep, and doing some mild exercise (if you are able).
  • Try not to make major life decisions while you are depressed.
  • Take your medications regularly.

Being depressed, in combination with being ill, can sometimes lead to the feeling that life is no longer worth living. Because depression can distort the way you view the world, you may start to see everything as if through a black cloud, including the value of your own life. With some help and support from family, friends, and health care professionals, these terrible feelings can start to lessen. Sometimes just talking about things that feel so painful and unspeakable can be the first step towards feeling better.

A note for family members

People who are truly depressed will not be able to get better on their own. If you suspect that someone is depressed, that person needs to be seen by a doctor so that a proper diagnosis can be made. Here are some suggestions for how you may be able to help:


  • People often feel better after taking antidepressant medication for a few weeks, and may be tempted to stop their pills. However, this may result in symptoms coming back. Encourage the person to continue taking medication as directed by the doctor.
  • Sometimes as people start to respond to treatment for depression, their energy improves before their depressed mood improves. This may be a time of higher risk for self-harm, since they may now actually have the energy to do something about their very depressed feelings. Family and friends should be aware that this is possible, and remain observant for signs of change such as becoming more withdrawn, or seeming more resolved and at peace.
  • Depressed people often feel frightened and alone, and may be reluctant to discuss how they are feeling. Acknowledge that the person is suffering and be there to listen. You don’t have to have any answers. Sometimes just acknowledging how difficult things are and showing you care by listening is the best help to give.
  • Encourage the depressed person, to the extent they are able, to go with you on walks or other outings.
  • Sometimes depressed people may talk about taking their own lives. Though it can be distressing to hear this, do not ignore any talk of suicide. It is important to share this information with the health care team to ensure the person’s safety, and to get the help they need! Do not hesitate to talk about painful feelings, as there is absolutely no evidence that asking people if they are having suicidal thoughts encourages suicidal behaviour. In fact, the opposite appears to be the case. Talking can provide a much-needed outlet, and usually results in an offer of help that at some level the person may be seeking.


What your health care team can do

Depression is usually best treated with a combination of psychotherapy and medications.


Psychotherapy provides individuals or groups with the opportunity to talk about their problems, fears, and concerns in a supportive, confidential environment. The mental health professionals providing psychotherapy listen to patients, empathize with them, and where appropriate, confront and challenge them. Therapy tends to be short-term, but individually tailored to meet the specific needs of each person.


Medication is often successful in relieving the symptoms of depression. The main class of medications currently used to treat depression is called antidepressants. Some antidepressants work by increasing levels of certain chemicals in the brain known as neurotransmitters. There is evidence that serotonin and norepinephrine are two of the main neurotransmitters that seem to be linked to depression. Other neurotransmitters have also been thought to be important.


Selective serotonin re-uptake inhibitors (SSRIs)
These drugs increase levels of serotonin in the brain. Examples of SSRIs include:

  • paroxetine (Paxil®)
  • sertraline (Zoloft®)
  • citalopram (Celexa®)
  • fluoxetine (Prozac®)
  • fluvoxamine (Luvox®).

People taking SSRIs generally experience few side effects. However, some people may experience tremor, nausea, diarrhea, and insomnia. Many side effects get better after a person has been taking the medication for a week or two.

Selective norepinephrine re-uptake inhibitors (SNRIs)
These drugs work to increase levels of norepinephrine in the brain. Venlafaxine (Effexor®) is one example. Side effects from SNRIs are similar to SSRIs.

Tricyclic antidepressants (TCAs)
These drugs also affect neurotransmitters. Examples of tricyclic antidepressants include:

  • amitryptyline (Elavil®)
  • desipramine (Norpramin®)
  • nortriptyline (Pamelor®)
  • imipramine (Tofranil®).

Though tricyclic antidepressants are an older class of medications compared to SSRIs and SNRIs, they can be very effective in managing depression in some people. Tricyclic antidepressants tend to cause more side effects than SSRIs and SNRIs, and may not be well tolerated by some people. TCAs have also been shown to be effective in the management of pain related to damaged nerves (neuropathic pain).


Psychostimulants are another group of medications that can be used to help manage depression. These medications work relatively quickly to improve a person’s mood and energy level. These are some examples of psychostimulants:

  • dextroamphetamine (Dexedrine®)
  • methylphenidate (Ritilan®)
  • pemoline (Cylert®).

Psychostimulants can also be helpful in reducing the drowsiness that people taking opioid medications experience, and may stimulate appetite in some people.

Content reviewed January 2023

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