Everyone feels sad or low sometimes. Depression is different. It is a common and serious medical condition that affects how you feel, think and handle daily activities, and it usually does not lift on its own just by trying harder. The encouraging news is that depression is treatable, and most people improve with the right support.
What is depression?
Major depressive disorder, often called clinical depression, involves a persistent low mood or loss of interest in activities for at least two weeks, along with other symptoms that interfere with work, school, relationships or self-care.
Depression can affect anyone, at any age. It is not a personal weakness or a character flaw.
Common symptoms
Doctors look for at least five of the following symptoms, present most of the day, nearly every day, for two weeks or more. At least one must be low mood or loss of interest or pleasure.
- Persistent sad, empty or hopeless mood
- Loss of interest or pleasure in hobbies and activities
- Changes in appetite or weight, either loss or gain
- Sleeping too much or too little
- Feeling restless, or moving and speaking more slowly than usual
- Fatigue or loss of energy
- Feelings of worthlessness or excessive guilt
- Difficulty concentrating, remembering or making decisions
- Thoughts of death or suicide
Other signs people often notice
- Irritability or anger, especially in men and teenagers
- Unexplained aches, headaches or digestive problems
- Withdrawing from friends and family
- Using alcohol or drugs more
Types of depression
- Major depressive disorder: episodes of depression lasting at least two weeks.
- Persistent depressive disorder (dysthymia): a lower-grade depressed mood lasting two years or more.
- Perinatal and postpartum depression: depression during pregnancy or after childbirth, which is more serious than the short-lived “baby blues.”
- Seasonal affective disorder: depression that follows a seasonal pattern, usually starting in fall or winter.
- Depression with psychotic features: severe depression with false beliefs or hallucinations.
- Bipolar disorder: involves episodes of depression and episodes of mania or hypomania. It is treated differently, so it is important to tell your clinician about any periods of unusually high energy, little need for sleep or risky behavior.
What causes depression?
Depression usually results from a combination of factors:
- Biology: changes in brain chemistry and brain circuits that regulate mood
- Genetics: a family history of depression raises risk
- Life events: loss, trauma, abuse, relationship problems, financial stress or major life changes
- Medical conditions: chronic pain, thyroid disorders, heart disease, diabetes, cancer and other illnesses
- Medicines and substances: some medicines, alcohol and drugs
- Hormonal changes: such as after childbirth or around menopause
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How depression is diagnosed
There is no blood test for depression. A clinician will ask about your symptoms, how long they have lasted and how they affect your life. Questionnaires such as the PHQ-9 are commonly used for screening. Your clinician may order blood tests to rule out conditions that can mimic depression, such as an underactive thyroid or vitamin B12 deficiency.
Treatment options
Psychotherapy (talk therapy)
Effective approaches include:
- Cognitive behavioral therapy (CBT): helps identify and change negative thought patterns and behaviors.
- Interpersonal therapy (IPT): focuses on relationships and life transitions.
- Behavioral activation: gradually reintroduces rewarding activities.
Therapy can be delivered in person, by video or through structured digital programs.
Medicines
Antidepressants can be very effective, particularly for moderate to severe depression. Common types include:
- SSRIs, such as sertraline, escitalopram and fluoxetine
- SNRIs, such as venlafaxine and duloxetine
- Other antidepressants, such as bupropion and mirtazapine
Antidepressants usually take 4 to 8 weeks to work fully. Side effects are often mild and may improve over time. Do not stop an antidepressant suddenly; your clinician can help you taper safely. Young people under 25 should be monitored closely when starting an antidepressant.
Combined treatment
For many people, therapy plus medicine works better than either one alone.
Other treatments
For depression that does not improve with standard treatments, options include esketamine nasal spray, transcranial magnetic stimulation (TMS) and electroconvulsive therapy (ECT), which is safe and highly effective for severe depression when given under modern medical care.
Self-care that supports recovery
- Keep a regular sleep schedule.
- Move your body every day, even a short walk.
- Spend time with people you trust.
- Break large tasks into small steps.
- Limit alcohol and avoid recreational drugs.
- Eat regular, balanced meals.
- Get outside in daylight.
Self-care supports treatment but does not replace it for moderate or severe depression.
When to get help
See a healthcare professional if low mood or loss of interest lasts more than two weeks or makes daily life hard. Your primary care clinician is a good starting point.
If you or someone you know is thinking about suicide or self-harm, get help immediately. In the United States, call or text 988 to reach the 988 Suicide & Crisis Lifeline, or call 911 if there is immediate danger.
More information is available from the National Institute of Mental Health.
Frequently asked questions
Is depression the same as sadness?
No. Sadness is a normal emotion that passes. Depression lasts longer, involves several symptoms and affects daily functioning.
Will I need medicine forever?
Not necessarily. Many people take an antidepressant for 6 to 12 months after they feel better and then taper off with medical guidance. Some people with repeated episodes benefit from longer treatment.
Can depression come back?
Yes. Knowing your early warning signs and continuing treatment for long enough lowers the risk of relapse.
The bottom line
Depression is common, real and treatable. If you have felt low, empty or uninterested in life for two weeks or more, reach out to a healthcare professional. Therapy, medicine and support can help you feel like yourself again.
This article is for general information and is not a substitute for advice from a qualified healthcare professional.