Depression is feeling sad, blue, unhappy, or down in the dumps. Most people feel this way once in a while.

Clinical depression is a mood disorder. It occurs when feelings of sadness, loss, anger, or frustration get in the way of your life over a long period of time. It also changes how your body works.

Depression is caused by changes in the chemicals in your brain. The condition may start during or after a painful event in your life. It may happen when you take certain medicines. It can also start after pregnancy.

Sometimes there is no clear trigger or reason.

You may notice some or all of the following problems. Talk to your health care provider if you have symptoms that last for 2 weeks or longer.

You will always have changes in your daily moods or feelings when you are depressed. You may:

• Feel sad or blue most or all of the time
• Feel bad-tempered or irritable most of the time, with sudden bursts of anger
• Not enjoy activities that normally make you happy, including sex
• Feel hopeless or helpless
• Not feel good about yourself, or have feelings of worthlessness, self-hate, and guilt

Normal daily activities also change when you are depressed. You may:

• Have trouble sleeping or sleep more than normal
• Have a hard time concentrating
• Move around more slowly or seem "jumpy" or agitated
• Feel much less hungry than before, or even lose weight
• Feel tired and lack energy
• Become less active or stop doing usual activities

Depression can lead to thoughts of death or suicide, which can be dangerous. Always talk to a friend or family member and call your provider when you have these feelings.

There are many things you can do at home to help manage your depression, such as:

• Get enough sleep.
• Follow a healthy diet.
• Take medicines correctly. Learn how to manage side effects.
• Watch for early signs that depression is getting worse. Have a plan if it does.
• Try to exercise more.
• Look for activities that make you happy.

Avoid alcohol and illegal drugs. These can make depression worse over time. They may also get in the way of your judgment about suicide.

Talk to someone you trust about your feelings of depression. Try to be around people who are caring and positive. Volunteering or getting involved in group activities may help.

If you are depressed in the fall or winter, ask your provider about light therapy. This treatment uses a special lamp that acts like the sun.

Some people may feel better after a few weeks of taking antidepressant medicines. Many people need to take these medicines for 4 to 9 months or longer. They need this to get a full response and prevent depression from coming back.

If you need antidepressant medicines, you should take them every day. Your provider may need to change the type of medicine you take or the dose.

Do not stop taking your medicine on your own, even if you feel better or have side effects. Always call your doctor first. When it is time to stop your medicine, your provider will slowly cut down the amount you take over time.

Talk therapy and counseling can help many people with depression. It also helps you learn ways to deal with your feelings and thoughts.

There are many different types of talk therapy. Effective treatment often combines:

• Talk therapy
• Lifestyle changes
• Medicine

American Psychiatric Association website. Depressive disorders. Diagnostic and Statistical Manual of Mental Disorders, 5th ed. Text Revision (DSM-5-TR), Washington, DC: American Psychiatric Association Publishing; 2022.

Fava M, Østergaard SD, Cassano P. Mood disorders: depressive disorders (major depressive disorder). In: Stern TA, Fava M, Wilens TE, Rosenbaum JF, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry. 2nd ed. Philadelphia, PA: Elsevier; 2016:chap 29.

National Institute of Mental Health website. Depression. www.nimh.nih.gov/health/topics/depression. Updated September 2022. Accessed December 8, 2022.