Published: 18 Jun 2025

ICD9: 311      ICD10: F32.9      ICD11: 6A70

Depression is a common and serious mood disorder that negatively affects how you feel, the way you think, and how you act.
It causes feelings of sadness and/or a loss of interest in activities you once enjoyed. It can lead to a variety of emotional and physical problems and can decrease a person's ability to function at work and at home.

Here's a breakdown of key aspects of depression:

Core Features:

Persistent Sadness or Empty Mood: Feeling down, sad, hopeless, or empty for most of the day, nearly every day, for at least two weeks. This is often a defining characteristic.
Loss of Interest or Pleasure: A significant decrease in interest or pleasure in activities you used to enjoy. This is called "anhedonia."

Other Common Symptoms:

In addition to the core features, other symptoms can include:

Changes in Appetite or Weight: Significant weight loss when not dieting or weight gain, or a decrease or increase in appetite nearly every day.
Changes in Sleep: Insomnia (difficulty sleeping) or hypersomnia (sleeping too much) nearly every day.
Fatigue or Loss of Energy: Feeling tired or having a lack of energy nearly every day.
Restlessness or Slowed Behavior: Agitation or restlessness (e.g., pacing, fidgeting) or slowed movements and speech noticeable by others. This is called psychomotor agitation or retardation.
Feelings of Worthlessness or Guilt: Feeling worthless or excessively guilty nearly every day.
Difficulty Thinking, Concentrating, or Making Decisions: Trouble focusing, remembering things, or making decisions.
Thoughts of Death or Suicide: Recurrent thoughts of death, suicidal ideation (thinking about suicide), a suicide attempt, or a specific plan for committing suicide. If you are having suicidal thoughts, please seek help immediately. You can call or text 988 in the US and Canada to reach the Suicide & Crisis Lifeline. In the UK, you can call 111.

Important Considerations:

Diagnosis: Depression is a clinical diagnosis made by a mental health professional (e.g., psychiatrist, psychologist, licensed therapist). They will evaluate your symptoms, medical history, and conduct an interview.
Severity: Depression can range in severity from mild, temporary sadness to severe, debilitating depression.
Types of Depression: There are different types of depressive disorders, including:
Major Depressive Disorder (MDD): The classic form of depression.
Persistent Depressive Disorder (Dysthymia): A chronic, low-grade form of depression that lasts for at least two years.
Seasonal Affective Disorder (SAD): Depression that occurs during specific seasons, usually winter.
Postpartum Depression: Depression that occurs after childbirth.
Bipolar Disorder: While not solely a depressive disorder, bipolar disorder involves periods of both depression and mania.
Causes: The exact cause of depression isn't fully understood, but it's believed to involve a combination of genetic, biological (neurochemical imbalances), environmental, and psychological factors.
Treatment: Depression is treatable. Common treatments include:
Therapy: Psychotherapy, such as Cognitive Behavioral Therapy (CBT) and interpersonal therapy (IPT), can help you learn coping skills and change negative thought patterns.
Medication: Antidepressant medications can help regulate brain chemistry and alleviate symptoms.
Lifestyle Changes: Exercise, a healthy diet, sufficient sleep, and stress management techniques can also play a role in managing depression.
Other Treatments: In some cases, other treatments like electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS) may be considered.

It's important to remember that:

Depression is not a sign of weakness. It's a medical condition.
You are not alone. Millions of people experience depression each year.
Help is available. If you think you might be depressed, talk to a doctor or mental health professional. Early diagnosis and treatment can significantly improve your quality of life.
Recovery is possible. With the right treatment and support, people can and do recover from depression.

If you are concerned about yourself or someone you know, please seek professional help. Mental health is just as important as physical health.