Persistent feelings of sadness and loss of interest. Review possible symptoms, contributing factors, assessment, warning signs and care options.
About Depression
Persistent feelings of sadness and loss of interest
Depression (major depressive disorder) is a common and serious medical illness that negatively affects how you feel, think, and act.
It causes persistent feelings of sadness and loss of interest in activities once enjoyed, and can lead to various emotional and physical problems.
Editorial update (28 September 2026): structured medical content awaits clinical reviewer sign-off.
How assessment may be approached
A qualified clinician may ask about mood, anxiety, sleep, appetite, functioning, medicines, substances, trauma, physical contributors and personal safety. Assessment is private and aims to understand the pattern before naming a diagnosis.
Options may include psychotherapy, practical support, treatment of contributors, medication when clinically appropriate, safety planning and follow-up. Do not stop prescribed psychiatric medicine without the prescriber's advice.
When to seek prompt care
Seek immediate local emergency or trusted-person support for thoughts, intent or plans of self-harm or harming others, severe agitation, inability to stay safe, psychosis, severe intoxication or inability to meet basic needs.
Symptoms
- Persistent sad mood
- Loss of interest in activities
- Changes in appetite
- Sleep disturbances
- Fatigue
- Difficulty concentrating
- Thoughts of death or suicide
Possible causes
- Genetic factors
- Brain chemistry
- Hormonal changes
- Life events
- Medical conditions
- Medications
Care and treatment options
- Psychotherapy
- Antidepressant medications
- Lifestyle changes
- Exercise
- Support groups
Key points
- Affects 280 million people worldwide
- Highly treatable
- Not a sign of weakness
- Can occur at any age
Preparing for a consultation
- How long symptoms have lasted and what has changed.
- Sleep, appetite, work, relationships and daily functioning.
- Medicines, substances, trauma and physical illness.
- Any safety concerns, urgent warning signs or support available.
Questions worth asking
- Is Depression the most likely explanation for these symptoms, and what alternatives should be checked?
- Which symptoms or findings would require urgent review?
- Are medicines, underlying health problems or lifestyle factors contributing?
- What tests or examinations are needed now, and what can safely wait?
- What treatment or self-care options are reasonable, and when should I be reviewed again?
- What is the expected benefit, limit, cost and follow-up plan for the suggested care?
Related conditions
Related clinicians
Medical information limitations
This page summarizes listed condition information and cannot confirm a diagnosis or choose treatment. Do not start, stop or change prescribed treatment based only on this page.
Common questions
What is Depression?
Persistent feelings of sadness and loss of interest This is general information; the name describes a possible diagnosis or clinical problem, not a personal diagnosis.
How might a clinician assess Depression?
A qualified clinician may ask about mood, anxiety, sleep, appetite, functioning, medicines, substances, trauma, physical contributors and personal safety. Assessment is private and aims to understand the pattern before naming a diagnosis.
What care may be discussed?
Care options listed include Psychotherapy, Antidepressant medications, Lifestyle changes, Exercise. Which option is appropriate depends on the confirmed cause, severity, preferences and contraindications.
When should Depression be checked urgently?
Seek immediate local emergency or trusted-person support for thoughts, intent or plans of self-harm or harming others, severe agitation, inability to stay safe, psychosis, severe intoxication or inability to meet basic needs.
How should I prepare for a consultation?
How long symptoms have lasted and what has changed. Sleep, appetite, work, relationships and daily functioning. Medicines, substances, trauma and physical illness. Any safety concerns, urgent warning signs or support available. Bring previous reports and a current medicine list where relevant.
Can this page diagnose or treat the condition?
No. A page about Depression can help you understand possible features and questions, but it cannot confirm a diagnosis or choose treatment. A qualified clinician should assess your symptoms, history and any test results.
General information only; it is not a diagnosis or a substitute for a qualified clinician’s advice.