Depression: Definition, Symptoms, And Treatments

Medically reviewed by Andrea Brant, LMHC
Updated October 13, 2023by BetterHelp Editorial Team
Content Warning: Please be advised, the below article might mention trauma-related topics that include suicide which could be triggering to the reader. If you or someone you love is having suicidal thoughts, contact the 988 Suicide & Crisis Lifeline at 988. Free, privileged support is available 24/7. Please also see our Get Help Now page for more immediate resources.
The World Health Organization (WHO) estimates that 3.8% of the population (approximately 280 million people) lives with depression. The experience of depression may vary from person to person, as each human being has a unique set of contributing circumstances, body chemistry, and other factors that impact their experiences.
While the definition of depression by psychologists may vary, the American Psychological Association defines it as “extreme sadness or despair that lasts more than days. [Depression] interferes with the activities of daily life and can cause physical symptoms such as pain, weight loss or gain, sleeping pattern disruptions, or lack of energy.” 

Experiencing Symptoms Of Depression?

Symptoms Of Depression

While depression is a mental health condition, the symptoms of depression are not limited to mental or emotional symptoms. The following are some possible physical symptoms that a person with clinical depression might experience:

  • Fatigue
  • Changes in sleeping patterns
  • Poor appetite
  • Weight loss
  • Weight gain
  • Chronic pain

Depressive symptoms can range from mild to severe and may or may not include the presence of a low or a depressed mood. Other common signs of major depression include feelings of emptiness or sadness, loss of interest in normally enjoyed activities, restlessness, and withdrawal from others. 

According to a systematic review of evidence from observational studies, depression may also cause someone to have a lower quality of life (though the review also showed that QoL improved after depression went into remission.) Many adults and adolescents who experience depression may also have difficulty with concentration and low self-esteem, and they may experience thoughts of self-harm or suicide.* 

If you or someone you know is experiencing suicidal thoughts, help is available. The 988 Suicide and Crisis Lifeline can be reached at 988 via phone call or text and is available 24/7.

Causes Of Depression

There can be multiple risk factors for depression. That being said, children and adolescents (and even older adults) who meet one or more of the following criteria do not automatically experience a major depressive episode.

Understanding the causes of depression can make a significant difference for some when it comes to preventive measures and clinical treatment.

Current literature suggests that individuals with families who have experienced depression may be more vulnerable to this mood disorder.

The quality of a person's lifestyle and upbringing can also be a common causal factor of depression. Someone who is constantly under stress or pressure or who is exposed to environments that are unhealthy may develop depression over time. Traumatic experiences that a person has not yet resolved can also cause symptoms of depression.

Finally, a clinical illness or specific medication (like a psychoactive drug) can alter an individual's brain chemistry and be a contributing factor to depression. This specific risk factor may vary according to the individual's brain chemistry and circumstances.

Types Of Depressive Disorders

There are several types of depressive disorders in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

Unipolar depressive disorders are characterized by depressive episodes alone, whereas bipolar disorders are characterized by manic and depressive episodes. This list focuses on unipolar depressive disorders.

Depending on the signs and symptoms that a person exhibits, they may be diagnosed via a set of criteria that correlate to a specific depressive diagnosis.

Understanding the different types of depressive disorders may help those experiencing symptoms to understand their condition better. Some of the most statistically common forms of depression include:

  • Dysthymic disorder: This condition is generally categorized as a continuous, long-term form of mild depression. The less severe signs and symptoms can occur sporadically and may come and go over a period of years.
  • Seasonal affective disorder (SAD): This disorder typically comes and goes with seasons. SAD may start for many in late fall and early winter, and it may be less noticeable during spring and summer.
  • Postpartum Depression: This condition may occur when a person experiences major depression during pregnancy or after delivery. If symptoms of depression are experienced exclusively after birth, clinicians may designate the diagnosis as postpartum depression.
  • This condition may occur when a person experiences major depression during pregnancy or after delivery. If symptoms of depression are experienced exclusively after birth, clinicians may designate the diagnosis as postpartum depression.
  • Premenstrual dysphoric disorder (PMDD): PMDD typically arises a week or two before a person’s period begins, and symptoms often dissipate a few days after their period begins.  PMDD is generally associated with symptoms such as a depressed mood, irritability, and tension. Premenstrual syndrome (PMS) is similar to PMDD; however, PMS generally involves fewer and less severe symptoms than PMDD.

Experiencing Symptoms Of Depression?

Treatment Options For Depression

Major depressive disorder can seriously affect a person’s quality of life. However, many people can find symptomatic relief with proper treatment (though it is also possible to experience treatment-resistant depression.) Below are several methods that have been shown to be effective in the treatment of depression.


Psychotherapy or talk therapy is one of the leading treatment options for depression. This treatment involves an individual working with a therapist who can get to know them and learn about their symptoms. At this point, the psychotherapist can then begin helping them develop an action plan with techniques that may help to reduce their symptoms and the severity of their condition.


Individuals who are experiencing depression may also be prescribed antidepressant medication. The specific medication that is prescribed can vary from person to person, especially when there is an underlying medical condition, such as heart disease.

Brain Stimulation Treatment Options

If other treatment options do not reduce the occurrence of symptoms of depression, brain stimulation therapies may be an option to explore. Brain stimulation therapies used to treat severe depression include repetitive transcranial magnetic stimulation and electroconvulsive therapy, or ECT. ECT is a medical procedure that is performed under anesthesia, and it has generally been reserved for patients with intense major depression who have not yet responded to other treatments.

How Can Online Therapy Support Those Living With Depression?

When an individual faces depression or another challenge, they may experience feelings of isolation. This feeling, along with physical manifestations of depression, can make it challenging for a person to leave home. If you don’t feel comfortable with in-office therapy at this time, you might try online therapy, which research has shown to be effective for depression and anxiety. 

Online therapy can be a helpful mental and emotional support option that can be received from the comfort of your own home or anywhere where you feel comfortable. With some therapy platforms, such as BetterHelp, you can also contact your therapist 24/7 via in-app messaging, and they’ll respond as soon as they can.


Depression and related disorders can look different on an individual basis. Strategic supportive methods can help to reduce symptom intensity in some individuals. Online therapy has been found to be effective for those experiencing symptoms of depression. With BetterHelp, you can be matched with an online therapist with training and experience treating people with depression. Take the first step to addressing depression and reach out to BetterHelp today.

Depression is treatable, and you're not alone

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