Depressive disorder (Depression)

Key facts

• Depression is a common mental disorder.
• Globally, an estimated 5% of adults suffer from depression.
• More women are affected by depression than men.
• Depression can lead to suicide.
• There is effective treatment for mild, moderate and severe depression.

Overview

Depressive disorder (also known as depression) is a common mental disorder. It involves a depressed mood or loss of pleasure or interest in activities for long periods of time.
Depression is different from regular mood changes and feelings about everyday life. It can affect all aspects of life, including relationships with family, friends and community. It can result from or lead to problems at school and at work.
Depression can happen to anyone. People who have lived through abuse, severe losses or other stressful events are more likely to develop depression. Women are more likely to have depression than men.
An estimated 3.8% of the population experience depression, including 5% of adults (4% among men and 6% among women), and 5.7% of adults older than 60 years. Approximately 280 million people in the world have depression (1). Depression is about 50% more common among women than among men. Worldwide, more than 10% of pregnant women and women who have just given birth experience depression (2). More than 700 000 people die due to suicide every year. Suicide is the fourth leading cause of death in 15–29-year-olds.
Although there are known, effective treatments for mental disorders, more than 75% of people in low- and middle-income countries receive no treatment (3). Barriers to effective care include a lack of investment in mental health care, lack of trained health-care providers and social stigma associated with mental disorders.

Symptoms and patterns

During a depressive episode, a person experiences a depressed mood (feeling sad, irritable, empty). They may feel a loss of pleasure or interest in activities.
A depressive episode is different from regular mood fluctuations. They last most of the day, nearly every day, for at least two weeks.
Other symptoms are also present, which may include:

• poor concentration
• feelings of excessive guilt or low self-worth
• hopelessness about the future
• thoughts about dying or suicide
• disrupted sleep
• changes in appetite or weight
• feeling very tired or low in energy.

Depression can cause difficulties in all aspects of life, including in the community and at home, work and school.
A depressive episode can be categorized as mild, moderate, or severe depending on the number and severity of symptoms, as well as the impact on the individual’s functioning. 
There are different patterns of depressive episodes including:

• single episode depressive disorder, meaning the person’s first and only episode;
• recurrent depressive disorder, meaning the person has a history of at least two depressive episodes; and
• bipolar disorder, meaning that depressive episodes alternate with periods of manic symptoms, which include euphoria or irritability, increased activity or energy, and other symptoms such as increased talkativeness, racing thoughts, increased self-esteem, decreased need for sleep, distractibility, and impulsive reckless behaviour.  

Contributing factors and prevention

Depression results from a complex interaction of social, psychological, and biological factors. People who have gone through adverse life events (unemployment, bereavement, traumatic events) are more likely to develop depression. Depression can, in turn, lead to more stress and dysfunction and worsen the affected person’s life situation and the depression itself.
Depression is closely related to and affected by physical health. Many of the factors that influence depression (such as physical inactivity or harmful use of alcohol) are also known risk factors for diseases such as cardiovascular disease, cancer, diabetes and respiratory diseases. In turn, people with these diseases may also find themselves experiencing depression due to the difficulties associated with managing their condition.
Prevention programmes have been shown to reduce depression. Effective community approaches to prevent depression include school-based programmes to enhance a pattern of positive coping in children and adolescents. Interventions for parents of children with behavioural problems may reduce parental depressive symptoms and improve outcomes for their children. Exercise programmes for older persons can also be effective in depression prevention.

Diagnosis and treatment

There are effective treatments for depression. These include psychological treatment and medications. Seek care if you have symptoms of depression.
Psychological treatments are the first treatments for depression. They can be combined with antidepressant medications in moderate and severe depression. Antidepressant medications are not needed for mild depression.
Psychological treatments can teach new ways of thinking, coping or relating to others. They may include talk therapy with professionals and supervised lay therapists. Talk therapy can happen in person or online. Psychological treatments may be accessed through self-help manuals, websites and apps. 
Effective psychological treatments for depression include:   

• behavioural activation
• cognitive behavioural therapy
• interpersonal psychotherapy
• problem-solving therapy.

Antidepressant medications include selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine.
Health-care providers should keep in mind the possible adverse effects associated with antidepressant medication, the ability to deliver either intervention (in terms of expertise, and/or treatment availability), and individual preferences.
Antidepressants should not be used for treating depression in children and are not the first line of treatment in adolescents, among whom they should be used with extra caution.
Different medications and treatments are used for bipolar disorder.

Self-care

Self-care can play an important role in managing symptoms of depression and promoting overall well-being.
What you can do:

• try to keep doing activities you used to enjoy
• stay connected to friends and family
• exercise regularly, even if it’s just a short walk
• stick to regular eating and sleeping habits as much as possible
• avoid or cut down on alcohol and don’t use illicit drugs, which can make depression worse
• talk to someone you trust about your feelings 
• seek help from a healthcare provider.

If you have thoughts of suicide:

• remember you are not alone, and that many people have gone through what you’re experiencing and found help
• talk to someone you trust about how you feel
• talk to a health worker, such as a doctor or counsellor
• join a support group.

If you think you are in immediate danger of harming yourself, contact any available emergency services or a crisis line.

WHO response

WHO’s Mental health action plan 2013–2030 highlights the steps required to provide appropriate interventions for people with mental disorders including depression. 
Depression and self-harm/suicide are among the priority conditions covered by WHO’s Mental Health Gap Action Programme (mhGAP). The Programme aims to help countries increase services for people with mental, neurological and substance use disorders through care provided by health workers who are not specialists in mental health. 
WHO has developed brief psychological intervention manuals for depression that may be delivered by lay therapists to individuals and groups. An example is the Problem management plus (PM+) manual, which describes the use of behavioural activation, stress management, problem solving treatment and strengthening social support. Moreover, the Group interpersonal therapy for depression manual describes group treatment of depression. Finally, the Thinking healthy manual covers the use of cognitive-behavioural therapy for perinatal depression.