This page is for general education and is not medical advice. It is not a substitute for diagnosis or treatment by a qualified professional. If this is an emergency, call 911 or 988.
Depression affects mood, body, and thinking. The two core symptoms are a persistent low mood and a loss of interest or pleasure in things you used to enjoy. Alongside these come changes in sleep, appetite, energy, and concentration, and feelings of worthlessness or guilt. For a diagnosis, symptoms are present most of the day, nearly every day, for at least two weeks and interfere with daily life — which is what separates depression from ordinary sadness.
Key facts
- Depression is common: NIMH estimates that about 8% of U.S. adults experience a major depressive episode in a given year.
- The two core symptoms are persistent low mood and loss of interest or pleasure (NIMH).
- Symptoms must last at least two weeks and affect daily functioning to indicate a depressive episode (NIMH, WHO).
- Depression has a real physical side — fatigue, sleep and appetite changes, and unexplained aches are part of it (MedlinePlus).
Emotional symptoms
- Persistent sad, anxious, or empty mood
- Loss of interest or pleasure in activities (including sex and hobbies)
- Feelings of hopelessness, worthlessness, or excessive guilt
- Irritability or restlessness
- Thoughts of death or suicide
Physical symptoms
- Fatigue or loss of energy
- Changes in sleep — insomnia, waking early, or sleeping too much
- Changes in appetite or weight
- Slowed movement and speech, or restlessness
- Aches, pains, or digestive problems without a clear physical cause
Cognitive symptoms
- Trouble concentrating, remembering, or making decisions
- A sense that thinking has slowed down
- Persistent negative thoughts about yourself, the world, or the future
When to seek help
Consider talking with a professional if symptoms last more than two weeks, cause real distress, or get in the way of work, relationships, or daily life. Depression often does not lift on its own, and treatment works. Only a professional can diagnose it — see how depression is diagnosed.
Seek help urgently if you have thoughts of suicide or self-harm — call or text 988 (Suicide & Crisis Lifeline) any time.
From our clinical review. The symptom people most often overlook is the loss of interest. They expect depression to look like crying or sadness, but for many it shows up as numbness — nothing feels good, nothing feels like anything. Naming that as a symptom, not a personal failing, is often the moment things start to shift.
Understanding your symptoms is the first step. If they sound familiar, explore depression treatment options or take a private, two-minute depression self-check.
Frequently asked questions
What are the main symptoms of depression?
Core symptoms are a persistent low mood and a loss of interest or pleasure, plus changes in sleep, appetite, energy, and concentration, and feelings of worthlessness or guilt — present most of the day, nearly every day, for at least two weeks.
What does depression feel like physically?
Depression is not only emotional. It commonly causes fatigue, changes in sleep and appetite, slowed movement or restlessness, and unexplained aches or pains. These physical symptoms are real and are part of the condition.
How long do symptoms last before it's depression?
A major depressive episode is diagnosed when symptoms are present most of the day, nearly every day, for at least two weeks. If low mood and loss of interest have lasted that long and affect daily life, it's worth talking to a professional.
Sources
- Depression — Signs and Symptoms — National Institute of Mental Health (NIMH)
- Depression — MedlinePlus, U.S. National Library of Medicine
- Depressive disorder (depression) — Fact sheet — World Health Organization (WHO)
Reviewed against the sources above. This page is educational and is not medical advice.