In this condition factsheet:
The Facts on Depression
Everyone feels sad or down at times, especially after experiencing a disappointment such as not getting the job you interviewed for. However, these feelings of sadness are usually short-lived.
Depression, on the other hand, is a medical condition characterized by long-lasting feelings of intense sadness and hopelessness associated with additional mental and physical changes. Depression can affect someone's personal, social, and professional life.
About 1 in 5 women and 1 in 10 men will suffer from depression at some point in life. Depression in children and adolescents occurs less commonly than in adults. Almost 1.5 million Canadians have serious depression at any given time, but less than one-third of these people seek medical help.
Types of Depression
There are several different types of depression, and the diagnosis is mostly determined by the nature and intensity of the mental and physical symptoms, the duration of the symptoms, and the specific cause of the symptoms, if that is known.
Clinical depression (or major depressive disorder, MDD) is the most serious type of depression in terms of the number and severity of symptoms, but there are significant individual differences in the symptoms and severity. People affected with major depression may not have suicidal tendencies and may never have received medical treatment. The person's interest and pleasure in many activities, energy levels, and eating and sleeping patterns are usually altered.
Dysthymia refers to a low-to-moderate level of depression that persists for at least 2 years, and often longer. While the symptoms are not as severe as in major depression, dysthymia can still have a major impact on a person's quality of life. It is often not recognized that dysthymia is a medical condition that responds equally effectively to the same treatments as major depression. Some people with dysthymia develop major depression at some time during the course of their depression.
Bipolar disorder (or manic depression) includes both high and low mood swings and a variety of other significant symptoms not present in other types of depression.
Other types of depression include seasonal affective disorder (SAD), depression with psychosis, and postpartum depression.
- SAD is a subtype of depression that regularly occurs at the same time of year (most often in the fall or winter months in North America).
- Depression with psychosis occurs when depression is severe and is associated with hallucinations (hearing or seeing things that are not there) or delusions (thoughts that are not based in reality).
- Postpartum depression often begins a few weeks after giving birth and is a subtype of depression. Postpartum depression is different from the temporary state known as the "baby blues" that often happens 24 to 72 hours after a woman gives birth. This temporary state is caused by the hormonal changes that occur during pregnancy and after giving birth and typically resolves in a week or so. Postpartum depression lasts longer than the "baby blues" and interferes with the woman's emotional and social functioning.
In some cases, depression is associated with other chronic medical conditions, which negatively impact the person's quality of life and well-being.
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Causes of Depression
There is no single cause of depression. Rather, it usually results from a combination of factors such as an imbalance of brain chemicals, family history, thoughts or beliefs that increase the risk of depression, and traumatic or stressful life events.
One factor involved in depression is an imbalance of the chemicals that help send messages in the brain. These chemicals in our brain also help regulate our emotions, behaviours, and thinking. How we perceive the world and what happens to us can also contribute to depression.
Depression has a genetic component (i.e., family history). While the tendency to be depressed can be genetically inherited, the onset of depression can be provoked by many factors.
Triggers of depression include:
- difficult or traumatic life changes (such as losing a loved one, ending a relationship, losing a job)
- medical conditions such as Parkinson's disease, stroke, lupus, hypothyroidism, chronic pain, and some types of cancer
- use of certain medications, including corticosteroids, anabolic steroids, narcotics, benzodiazepines, progesterone (found in some female hormonal pills), and street drugs such as amphetamines
- alcohol, which has short-term and possibly long-term depressive effects
It is important to recognize that depression is not something you can "get over" on your own, and it is not the result of personal weakness or an inability to cope.
Symptoms and Complications of Depression
Although we all feel sad sometimes, clinical (major) depression is diagnosed when a person experiences at least 5 of the symptoms below (one of which must be depressed mood or loss of interest or pleasure in daily activities), on most days for at least 2 weeks:
- depressed mood (sadness)
- loss of interest or pleasure in daily activities
- changes in appetite or weight
- fatigue or loss of energy
- insomnia (trouble sleeping) or chronic oversleeping
- noticeable changes in activity level (agitated or slowed down)
- feelings of worthlessness or guilt
- difficulty concentrating or making decisions
- recurring thoughts of death or suicide
Other symptoms of depression may include:
- loss of interest in work and other activities
- avoiding family members and friends
- crying easily
- hallucinations (hearing or seeing things that aren't there)
- delusions (having thoughts that are not based on reality)
- body aches and pains, such as headache, joint pain, or abdominal pain (these symptoms may be reported rather than feelings of sadness)
Clinical depression may vary in its severity, and in its extreme forms (i.e., thoughts of suicide) it can be life-threatening and require immediate medical attention.
Symptoms of other forms of depression, although generally milder, may still negatively affect a person's daily activities and quality of life.