what is a depression

AI Overviews: matched the NHS on everything we checked.

13 November 2026

Depression is a common, serious mood disorder characterized by a persistent feeling of sadness, emptiness, or a loss of interest and pleasure in daily activities for weeks, months, or longer.123

Core Definition & Overview

According to the World Health Organization, depression is different from normal, temporary mood fluctuations or emotional responses to everyday life. It is a real medical and psychological condition—not a personal weakness or something a person can simply "snap out of".123

Key Characteristics & Symptoms

Depression affects how you feel, think, and handle daily tasks such as working, sleeping, and eating. Common signs include:123

  • Emotional: Persistent sadness, hopelessness, irritability, emptiness, or a feeling that life is no longer worth living.
  • Physical: Constant fatigue, sleep disturbances (insomnia or oversleeping), changes in appetite or weight, and unexplained aches or pains.
  • Cognitive: Difficulty concentrating, remembering details, or making decisions.
  • Behavioral: Withdrawal from friends, family, and social activities, or a lack of motivation.123456

Common Types of Depression

  • Major Depressive Disorder (MDD): Pervasive low mood and loss of interest lasting for at least two weeks.
  • Persistent Depressive Disorder (PDD): Chronic, long-term depression lasting for two years or more.
  • Seasonal Affective Disorder (SAD): Depressive episodes that occur at a specific time of year, most commonly during the winter months.
  • Perinatal and Postnatal Depression: Depression occurring during pregnancy or within the first year after childbirth.123

Treatment and Support

Depression is treatable. Standard care typically involves a combination of talking therapies (such as cognitive behavioral therapy or CBT) and/or antidepressant medication, alongside lifestyle changes.123If you or someone you know is struggling, help is available:

What we checked
Cited the NHS or an accredited sourceYes
Used UK termsYes
Named a UK charityYes
Said to check with a professionalYes

What the NHS says

No answer key for this question. It is checked on sources and UK terms only, because the NHS page doesn’t state one clear answer we can check against.

Where it got this

Six of its twelve sources are from outside the UK. It cited the NHS two times.

The NHS 2On the PIF TICK list 2Overseas 6YouTube 2
NHS websiteOverview - Depression in adults - NHS
NHS
Mayo ClinicDepression (major depressive disorder) - Symptoms and causes - Mayo Clinic
World Health OrganizationDepressive disorder (depression) - World Health Organization (WHO)
NCBI Bookshelf (US National Library of Medicine)Depression - StatPearls - NCBI Bookshelf - NIH
YouTubeWhat is depression?
Month by monthFirst asked in November 2026
MonthAI OverviewsAI ModeChatGPT
November 2026–––
About this questionA real Google search, about 8,100 a month in the UK
Where it came from
A real Google search, about 8,100 a month in the UK
Asked since
November 2026
Kind of question
Understanding it · What is this condition
Conditions
Depression
Typed as
A sentence, in everyday words
Question ID
Q0966.v1