Depression
Also called: Major depressive disorder, Clinical depression
A common, treatable illness of persistently low mood or loss of interest lasting at least two weeks, affecting thinking, sleep, appetite and daily functioning. It is not a weakness and not something people can simply 'snap out of'.
Condition-specific references are below. Individual claims and this page have not been clinically reviewed. Read about this content.
About 280 million people worldwide; a leading cause of disability.
What happens in the body
Arises from interacting genetic, biological (stress-hormone and neurotransmitter systems, inflammation), psychological and social factors.
Causes
- Combination of genetic vulnerability and life stressors
Risk factors
- Family history
- Stressful life events, loss, abuse
- Chronic physical illness and pain
- Loneliness
- Substance misuse
- After childbirth (postnatal depression)
Symptoms
- Persistent low mood
- Loss of interest or pleasure
- Sleep and appetite changes
- Fatigue
- Poor concentration
- Feelings of worthlessness or guilt
- Thoughts of death or suicide
Diagnosis — tests and examinations
- Clinical interview (DSM-5/ICD-11 criteria)
- Questionnaires (PHQ-9)
- Blood tests to exclude thyroid disease, anaemia or vitamin deficiency
Treatment
Medicines and medical treatment
- Antidepressants (SSRIs such as sertraline, escitalopram; SNRIs; mirtazapine) for moderate–severe depression, usually continued 6+ months after recovery
- Esketamine for treatment-resistant depression
Operations and procedures
- Electroconvulsive therapy for severe or life-threatening depression
- Repetitive transcranial magnetic stimulation (rTMS)
Self-care, home remedies and lifestyle
- Psychological therapy: CBT, behavioural activation, interpersonal therapy
- Regular physical activity
- Sleep routine, social contact
- Limit alcohol and drugs
- Reach out to trusted people
Possible complications
- Suicide
- Self-neglect
- Worse outcomes of physical illness
- Substance misuse
Prevention
- Social support, physical activity, early help during stressful periods
Outlook
Most people recover with treatment; recurrence is common and can be reduced by maintenance therapy.
When to see a doctor
Seek help if low mood lasts more than two weeks. If you have thoughts of suicide, contact emergency services or a crisis line immediately.
Sources and further reading
These sources cover this condition. They have not been checked against every statement on this page.
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Educational overview, not medical advice. Treatment varies by person and location. Consult a qualified health professional for diagnosis or care. Read our content and model notes and privacy information.