How Common is Depression? Facts and Statistics

Whether you are dealing with low-grade depression or more serious and severe mood disorders, seeking help from a healthcare professional is key. With the right treatment plan and coping mechanisms in place, it is possible for anyone to overcome the challenges of depression. 

On this page, we will cover everything you need to know about depression, its symptoms, and the causes behind it. Plus, we will discuss different treatment options for depression, as well as 10 key depression statistics that everyone should know about. 

What is Depression?

Depression is a term used to describe the feeling of a depressed mood that is persistent over a long period of time. In psychology, this is called major depressive disorder or clinical depression. 

Major depressive disorder — or MDD — is the most common form of depression and is characterized by symptoms persisting over at least two weeks. However, MDD is not the only type of depression. 

The other types of depression include: 

• Persistent depressive disorder (PDD): PDD is a type of low-grade depression that is also known as dysthymia or dysthymic disorder. Overall, PDD is similar to MDD, but its symptoms are less severe and persist for longer periods. 
• Bipolar disorder: Bipolar disorder is a mood disorder that is characterized by a cycle of manic and depressive phases. There are two types of bipolar disorder. Bipolar I is considered more severe, with serious manic and depressive episodes. Bipolar II involves less severe mania called hypomania. Mania symptoms include elevated energy, lack of sleep, racing thoughts, agitation, high libido, impulsivity, and abnormally high self-confidence. Severe mania can also include delusions and hallucinations. 
• Postpartum depression (PPD): PPD occurs after giving birth and is caused by hormonal shifts in the body. While feeling some level of depression and mood swings after birth is normal, a PPD diagnosis is considered if symptoms persist for more than two weeks. 
• Premenstrual dysphoric disorder (PMDD): PMDD occurs the week before a person’s menstrual cycle, improving once the cycle has finished. Due to its similarity to PMS (premenstrual syndrome), this disorder can easily go undiagnosed. However, its symptoms are considered more severe and debilitating than regular PMS. 
• Seasonal affective disorder (SAD): SAD is a type of depression disorder that occurs during the changing of seasons, beginning in the late fall and early winter. The cause behind SAD is attributed to a disruption of the body’s circadian rhythm due to reduced daylight hours. 

What are the Symptoms of Depression?

The symptoms of depression can vary depending on the type of disorder you are dealing with. Here is a breakdown of the symptoms for each of the above-listed types of depression:

MDD:

• Persistent sadness
• Inability to feel pleasure (anhedonia)
• Lack of interest in hobbies, work, and passions
• Weight change
• Delayed emotional and physical reactions
• Limited or excessive sleep
• Fatigue
• Difficulty concentrating
• Suicidal ideation

PDD:

• Similar symptoms to MDD, but less severe and more persistent
• Two-year period of depression symptoms for adults
• One-year period of depression symptoms for teens and children

Bipolar disorder (manic phase):

• Unusually elevated energy
• Lack of sleep
• Racing thoughts
• Easily distracted
• Agitation, irritability, hostility, or aggression
• Impulsive behaviour
• Unusually high libido
• Delusions or hallucinations

Bipolar disorder (depressive phase):

• Unexplained sadness or crying
• Weight change
• Limited or excessive sleep
• Poor hygiene
• Anhedonia
• Difficulty concentrating
• Indecisiveness
• Suicidal ideation and self-harm

PPD:

• Difficulty bonding with your newborn baby
• Social withdrawal
• Feelings of sadness
• Anhedonia
• Appetite changes
• Feelings of inadequacy 
• Suicidal ideation
• Severe cases can include thoughts of harming the baby

PMDD:

• Mood swings
• Binge eating
• Irritability
• Anxiety or panic attacks
• Limited or excessive sleep
• Difficulty concentrating
• Physical PMS symptoms (bloating, cramps, breast tenderness, joint pain)

SAD:

• Similar symptoms to MDD and PDD, except notably more present during the fall and winter seasons. 

What Causes Mood Disorders?

When assessing a mood disorder in any given individual, there are many potential causes that healthcare practitioners look for. 

According to Cleveland Clinic, these include:

• Chemical imbalances: For many people suffering from depression, the root cause can be a chemical imbalance within their brain. To resolve this, medications are used to bring these chemicals back to the proper levels and equilibrium. 
• Genetics and family history: Depression and mood disorders can be genetically passed on. As such, a healthcare professional will often ask detailed questions about your family history to identify any past occurrences of such disorders in your bloodline. 
• Trauma: Traumatic events (violent incidents, major negative life changes, severe injuries, etc.) can both temporarily and permanently alter the brain. As a result of a traumatic event, a person may develop a depressive or mood disorder. 
• Brain structure and function: In the case of bipolar disorder, the brain structure and function may be the root cause behind the disorder. Understanding the structure and function of a person’s brain helps healthcare professionals to better determine an effective treatment plan for this type of disorder. 
• Physical illness and certain medications: When you suffer from specific physical illnesses (cancer, diabetes, Parkinson’s disease, heart disease, etc.) and take the associated medications, depression can be a common side effect. If left untreated, this depression may persist and develop into a disorder. 

Who is Affected by Depression?

While anyone can develop depression and mood disorders, there are certain groups of people who are more likely to experience the condition.

People who are at higher risk of depression include women and older adults.

Additionally, depression and mood disorders can have a major impact not just on the person with the disorder but on the people around them as well. This is especially true if a depression disorder is comorbid with alcohol or drug addiction, as these conditions can result in emotional, financial, and even physical strain on a person’s family and loved ones. 

Treatment for Depression and Anxiety

Although depression can be highly debilitating when left unaddressed, it is considered a manageable condition with the proper treatment. 

Some popular treatment options include therapy, lifestyle changes, alongside ongoing progress check-ins with your doctor, to ensure that your treatment is helping improve your symptoms.

For therapy, the most common types of therapy used to treat depression and mood disorders are cognitive behavioural therapy (CBT) and dialectical behaviour therapy (DBT). CBT focuses on identifying, questioning, and altering negative thoughts, while DBT focuses on mindfulness and emotional regulation. 

DBT is often used as part of a treatment plan for both bipolar disorder and borderline personality disorder.  

When learning how to deal with depression in a healthy way, it is important to remember that depression can occur alongside other conditions — with the most common comorbid conditions being anxiety and addiction.

Depression statistics everyone should know 

1. One in 8 adults (12.6%) identified symptoms that met the criteria for a mood disorder at some point during their lifetime, including 11.3% for depression and 2.6% for bipolar disorder. (Source: Government of Canada)

2. More than 50% of individuals who have an episode of major depression experience a recurrence. (Source: Government of Canada)

3. Depression is a common illness worldwide, with an estimated 3.8% of the population affected, including 5.0% among adults and 5.7% among adults older than 60 years (1). (Source: World Health Organization)

4. Although there are known, effective treatments for mental disorders, more than 75% of people in low- and middle-income countries receive no treatment. (Source: World Health Organization)

5. Young people aged 15 to 24 are more likely to experience mental illness and/or substance use disorders than any other age group. (Source: camh)

6. Nearly 50% of all people diagnosed with depression are also diagnosed with an anxiety disorder. (Source: Very Well Mind)

7. According to data from the 2017 National Survey on Drug Use and Health, 17.3 million adults in the United States — equaling 7.1% of all adults in the country — have experienced a major depressive episode in the past year. (Source: SAMHSA)

8. 20% of adolescent girls have experienced a major depressive episode. (Source: Very Well Mind)

9. 6.8% of adolescent boys have experienced a major depressive episode. (Source: Very Well Mind)

10. 60% of children and adolescents with depression are not getting any type of treatment. (Source: Very Well Mind)

IMPORTANT NOTE: Though depression can be a highly debilitating mental health condition, treatment options are available and the condition is widely considered to be manageable with the right approach.

Healthcare professionals may recommend a combination of therapy, and lifestyle changes to treat depression and mood disorders. They’ll also book regular check-ins with you, so that they can help you monitor and track your progress throughout the treatment plan.

Want to see how we can help you in your treatment journey? Connect with one of Felix's healthcare practitioners today.

If you are having suicidal thoughts, please seek help immediately by going to your nearest emergency department or by calling 911. You can also contact Crisis Services Canada’s national suicide-prevention hotline at 1-833-456-4566 if you are considering suicide or are concerned about someone who may be.