How is sadness different from depression?

Ordinary sadness lifts within days; depression lasts two weeks or more and impairs daily functioning.

Are antidepressants addictive?

They aren't addictive, but stopping abruptly can cause discontinuation symptoms, so taper with a doctor.

Major depressive disorder

🧠 Psychology By CampusDown Wiki Editorial Team Last updated October 26, 2026

Major depressive disorder is a common mental illness. For at least two weeks, low mood or loss of interest persists nearly every day, alongside changes in sleep, appetite, concentration, and self-worth. It is a treatable condition, not a lack of willpower.

Contents

1. History of the concept
2. Symptoms and causes
3. Treatment and getting help
4. FAQ
5. References

History of the concept

Hippocrates blamed deep sadness on an excess of black bile, or melancholia. In the late 19th century German psychiatrist Emil Kraepelin separated depressive states from manic-depressive illness, and Freud's 1917 essay "Mourning and Melancholia" tied depression to loss. In the 1950s, iproniazid (a tuberculosis drug) and imipramine were found by chance to lift mood, giving rise to the monoamine hypothesis. DSM-III coined "major depressive disorder" in 1980, and fluoxetine (Prozac) brought treatment into the mainstream in 1987.

Symptoms and causes

The core features are depressed mood or loss of interest and pleasure. Diagnosis requires five of nine symptoms for more than two weeks. The other seven are changes in sleep, changes in appetite or weight, fatigue, worthlessness or guilt, poor concentration, agitation or slowing, and thoughts of death. The PHQ-9 screener mirrors these criteria. The stress-vulnerability model combines genetic risk, an overactive stress (HPA) axis, inflammation, and thinking habits such as rumination and cognitive distortions. Onset after childbirth suggests postpartum depression, and alternating highs point to bipolar disorder.

Treatment and getting help

For mild to moderate depression, cognitive behavioral therapy and interpersonal therapy work about as well as antidepressants. For more severe cases, combining them with an SSRI lowers relapse. Medication takes two to four weeks to work and is usually continued for six to twelve months after recovery. Exercise and regular sleep also have evidence behind them. In the US, call or text 988; in South Korea, call 109.

FAQ

How is sadness different from depression?: Ordinary sadness lifts within days; depression lasts two weeks or more and impairs daily functioning.
Are antidepressants addictive?: They aren't addictive, but stopping abruptly can cause discontinuation symptoms, so taper with a doctor.

Sources reviewed: 2026-10-26

References

American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.; DSM-5-TR).
World Health Organization. (2023). Depressive disorder (depression) fact sheet.
보건복지부·국립정신건강센터. (2022). 정신건강실태조사.

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PHQ-9 Depression ScreeningHow the PHQ-9 depression screening questionnaire works: the nine DSM-based questions, scoring from 0 to 27 and what each range means, why question 9 needs immediate follow-up, its accuracy at a cutoff of 10, and screening vs. diagnosis.🧠 Psychology Cognitive-Behavioral TheoryCognitive-behavioral theory (CBT) in broad view: behavior therapy techniques, the cognitive turn with Ellis and Beck, Meichenbaum's self-instructional training and stress inoculation, third-wave therapies (ACT, DBT, MBCT), and evidence.🧠 Psychology RuminationWhat rumination is, Susan Nolen-Hoeksema's response styles theory linking it to depression, how it differs from healthy reflection, and evidence-based ways to break the cycle: distraction, concrete thinking, and mindfulness.🧠 Psychology Postpartum depressionWhat postpartum depression is, peripartum onset in DSM-5-TR, how it differs from the baby blues, symptoms and risk factors, EPDS screening, treatment, and where to get help.🧠 Psychology Bipolar disorderWhat bipolar disorder is, features of manic, hypomanic and depressive episodes, bipolar I, bipolar II and cyclothymia, treatment with mood stabilisers and psychotherapy, and where to get help.🧠 Psychology Cognitive distortionsThe common cognitive distortions identified by Aaron Beck and popularized by David Burns—all-or-nothing thinking, catastrophizing, mind reading, "should" statements, and more—with everyday examples and CBT techniques to reframe them.🧠 Psychology

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This article was last updated on October 26, 2026. It is based on widely recognized original works and textbooks; when citing it in a paper, please check the original sources listed in the references.