Major depressive disorder, or clinical depression, is a common but serious mood disorder that is much more than unhappiness. People with depression often feel sad, empty or irritable for long periods of time. Depression causes changes to the body (e.g., sleep problems or appetite problems) and the mind (e.g., trouble concentrating), which can affect people’s day-to-day functioning (APA, 2013).
There are several types of depressive disorders, including:
- major depressive disorder (includes major depressive episode)
- persistent depressive disorder (a persistent low mood)
- substance/medication-induced depressive disorder
- depressive disorder due to another medical condition.
In addition, many people experience seasonal affective disorder (SAD), which is linked to the weather and the time of the year; some women experience premenstrual dysphoric disorder, which includes symptoms of severe depression, irritability and tension before their period; and approximately 10 per cent of women will experience postpartum depression after they give birth (CAMH, 2012).
How common is depression?
Depression is one of the most common mental health problems. In a 2017 survey, 38 per cent of Canadians said that, at least once in the past year, they felt sad or hopeless almost every day for more than a couple of weeks.
40 per cent of respondents to a 2016 survey have experienced feelings of anxiety or depression, but never sought medical help for it.
Signs and symptoms of depression
Someone may have depression if they have symptoms of depression most days, and these symptoms last for most of the day, persist for more than two weeks and negatively affect a person’s functioning at work, at school or in social relationships. Symptoms of depression can vary from minor to severe and can include:
- sadness throughout the day, nearly every day
- a loss of interest in favourite activities
- feelings of worthlessness
- excessive or inappropriate feelings of guilt
- thoughts of death or suicide
- trouble making decisions
- trouble concentrating
- feelings of irritability
- fatigue or lack of energy
- aches and pains (e.g., headaches, stomach pain or joint pains)
- sleeping too much or too little
- change in appetite or weight
- feelings of restlessness or being slowed down.
Risk factors and causes of depression
Depression results from interactions between genetic, biological, environmental and psychological factors. Depression can begin at any age, but usually starts when a person is in their late teenage years, or in early adulthood (Wang et al., 2010). Many long-term mood and anxiety disorders in adults begin as high levels of anxiety in children (NIMH, 2018). Women, young people, those with persistent conditions and people with a family history of major depressive episodes are more likely to develop major depression (Wang et al., 2010).
Risk factors for depression include:
- personal or family history of depression
- major life changes, trauma, including intergenerational trauma, or stress
- certain physical illnesses and medications
- Even though risk factors may increase someone’s chances of developing depression, it is not guaranteed that they will develop it.
Family history
Having a family history of major depressive episodes is the greatest risk factor for having a major depressive episode. It is not clear what accounts for this strong correlation, as it could involve a combination of genetics/biology, childhood trauma and current life circumstances (determinants of health).
Trauma
Traumatic experiences can be any negative experience that deeply affects a person. They are unsettling and impact a person’s ability to adapt to the normal stresses of life. Traumatic experiences could include being in a car accident, witnessing violence, being abused or living through a natural disaster or a war. Trauma, especially in childhood, causes health disparities. It is a root cause of adult disease and high-risk behaviours. Trauma is more likely to affect the most vulnerable people and populations (Kimberg, 2016).
It is important to recognize that anyone could have past trauma. In fact, for clients in a clinical practice or service, the rates of trauma can be as high as 80 to 90 per cent (Saunders & Adams, 2014). A history of trauma is a major risk factor for depression.
First Nations, Inuit and Metis intergenerational trauma
The legacy of residential schools has deeply affected the mental health of First Nations, Metis and Inuit people. A research project that looked at the case files for a sample of residential school survivors found that 75 per cent contained information about mental health. The most common mental health diagnoses were post-traumatic stress disorder (PTSD), substance abuse disorder and major depression (Health Canada, 2017).
Illness/medications
Depression can be both a cause and an effect of physical illness. People with depression are two times more likely to have a stroke and 1.5 times more likely to develop cancer. On the other hand, 17 to 27 per cent of people with heart disease and 22 to 29 per cent of people with cancer develop depression (MDSC, 2013).
Depression can emerge with physical illnesses, such as diabetes, cancer, heart disease and Parkinson’s disease, especially in adults who are middle-aged or older. Sometimes the medications for these illnesses can cause side-effects that may lead to depression.
Substance use problem
A substance use problem is characterized by a person’s inability to stop using a substance, trouble with self-control, cravings and lack of self-awareness about problems with behaviours and relationships.
Treatment
Depression can be treated so that people recover and maintain day-to-day functioning. Treatment comes in many forms, including counselling, individual and group therapy, medication, electroconvulsive therapy (ECT) and alternative medicine treatments. These treatments may be used individually or together.
Depression can be a major sign that a person has unmet needs and may benefit from exploring new ways of thinking, especially if they’ve become very self-critical. Depression can result from current or past life experiences or current living conditions, including housing or employment stress. Depression should not be ignored. Counselling can help a person develop the skills that will improve their current state of mind and their future resilience. Self-help organizations, run by clients of the mental health system and their families, can also be an important part of treatment and recovery for people with depression and their families (CAMH, 2012).
New treatments, such as brain stimulation therapy, and alternative therapies, such as repetitive transcranial magnetic stimulation (rTMS), show positive results, especially for people who have histories of unsuccessful treatments. However, these new treatments are not yet widely available, are difficult to gain access to and may not be covered by provincial health care plans.
A person’s treatment plan is based on the nature and severity of the depression (e.g., ECT is an only an option for severe depression), past responses to treatment and their personal and family’s preferences.
Brain stimulation therapy
Brain stimulation therapies use electricity to activate or inhibit the brain. They seem promising for treating certain mental disorders that do not respond to other treatments.
Repetitive transcranial magnetic stimulation (rTMS)
rTMS uses short magnetic pulses to stimulate nerve cells in the brain. Recently, researchers have been focusing on the use of rTMS as a treatment option for major depressive disorder.
While seeing a health care professional is a key part of the treatment process, developing self-help skills is also very important. Depression can affect many different areas of someone’s life. Living a healthy lifestyle that includes being physically active, eating well, sleeping, spending time outdoors and limiting alcohol and other substance use can speed up recovery and help prevent the return of symptoms (Bilsker & Paterson, 2005).
A Note about Suicide:
If you are experiencing thoughts of suicide, this is a mental health emergency and you are deserving of help. Call or text 9-8-8 to speak to someone immediately, or visit the 9-8-8: Suicide Crisis Helpline. For more information about signs, symptoms and how to help yourself or someone else thinking about suicide, see https://www.camh.ca/en/health-info/mental-illness-and-addiction-index/suicide