Depression is a common but serious mental health condition that affects how a person feels, thinks, sleeps, eats, and manages daily life. It can cause ongoing sadness, emptiness, hopelessness, irritability, or loss of interest in activities that were once enjoyable. Depression is more than a temporary bad mood or a normal response to a difficult day.
Major depressive disorder is generally diagnosed when symptoms are present most of the day, nearly every day, for at least two weeks and interfere with work, school, relationships, self-care, or other responsibilities. Depression can be mild, moderate, or severe, and some people experience repeated episodes. Effective treatment may include psychotherapy, medication, or both.
Depression – National Institute of Mental Health
Explains depression symptoms, types, risk factors, diagnosis, and treatment.
Provides patient-friendly information about depression and available treatments.
adults of any age, background, sex, gender, income level, or education level. Severe depression can significantly interfere with a person’s ability to work, maintain relationships, care for themselves, or complete normal daily activities.
The risk may be higher in people who have:
Depression can also occur without an obvious cause.
Depression affects people differently. Not everyone experiences every symptom.
Common symptoms include:
Some people experience depression mainly as irritability, fatigue, physical discomfort, poor concentration, or loss of motivation rather than obvious sadness.
Depression is diagnosed through a clinical evaluation rather than one blood test or scan.
A healthcare provider may ask about:
The provider may use a questionnaire such as the Patient Health Questionnaire-9, commonly called the PHQ-9, to measure symptom severity and monitor treatment response. A screening score can identify possible depression but does not replace a complete clinical assessment.
Before prescribing an antidepressant, the provider may ask about symptoms of bipolar disorder. Antidepressants used without appropriate mood-stabilizing treatment may worsen mania or mood instability in some people with bipolar disorder.
The U.S. Preventive Services Task Force recommends depression screening for adults, including older adults and pregnant and postpartum people, when systems are available for diagnosis, treatment, and follow-up.
Depression usually develops from a combination of biological, psychological, environmental, and social factors rather than one single cause.
Possible contributing factors include:
Medical conditions that may contribute to depressive symptoms include thyroid disease, anemia, vitamin deficiencies, neurological conditions, autoimmune disorders, cancer, heart disease, and chronic pain conditions.
Factors that may worsen depression or delay recovery include:
Depression may also worsen during major life changes, after childbirth, during certain seasons, or when a medical illness becomes more severe.
Depression cannot always be prevented, but early recognition and treatment may reduce severity and complications.
Helpful measures include:
A relapse plan may include early symptoms, preferred providers, effective treatments, supportive contacts, crisis numbers, and steps to reduce access to lethal means.
Laboratory testing cannot directly confirm major depressive disorder, but it may help identify medical conditions that cause or worsen similar symptoms.
Possible tests include:
Testing should be based on the person’s symptoms, physical examination, medical history, and medications.
Medical Tests – NIH MedlinePlus
Provides patient-friendly explanations of commonly ordered laboratory tests.
Brain imaging is not routinely needed to diagnose depression.
Possible assessments include:
A provider may order a CT scan, MRI, sleep study, or other testing when symptoms suggest a neurological disorder, sleep disorder, head injury, seizure condition, or another medical cause.
Depression is treatable, including severe depression. Treatment is individualized based on symptoms, severity, medical history, preferences, past treatment response, pregnancy status, and safety concerns.
Treatment options may include:
Psychotherapy, medication, or a combination of both are standard treatments. Finding the most effective approach may require adjustments over time. Brain-stimulation treatment may be considered when symptoms are severe or have not adequately improved with other treatments.
Common Therapy Approaches
Lifestyle changes can support treatment but should not be presented as a substitute for professional care.
Helpful changes may include:
When motivation is very low, begin with small goals such as showering, eating a meal, walking briefly, opening curtains, or contacting one supportive person.
Antidepressants may reduce symptoms of depression. Medication selection depends on symptoms, side effects, other medical conditions, medication interactions, pregnancy status, cost, and previous response.
Common medication groups include:
Antidepressants often require time to provide their full benefit, and more than one medication may need to be tried. Do not stop an antidepressant suddenly without medical guidance because withdrawal-like symptoms or worsening depression may occur.
Possible side effects include:
Contact the prescriber promptly for:
All medication and supplement use should be discussed with a healthcare professional because interactions may occur.
Antidepressants – NIH MedlinePlus
Explains how antidepressants are used, potential side effects, and medication safety.
Most people with depression do not require a procedure. Specialized treatments may be considered for severe, psychotic, suicidal, catatonic, or treatment-resistant depression.
Possible procedures include:
Electroconvulsive therapy may be considered when rapid improvement is necessary, such as severe suicidal depression, psychotic depression, catatonia, inability to eat or drink, or failure of other treatments.
Many people recover from a depressive episode with appropriate treatment. Improvement may occur gradually rather than all at once. Sleep, appetite, concentration, and energy may improve before mood fully improves.
Long-term outcomes depend on:
Some people experience one episode, while others have recurring or chronic depression. Continued treatment after symptoms improve may reduce the risk of relapse. People with repeated episodes may benefit from longer-term therapy or medication.
Do not assume treatment has failed because improvement is not immediate. Medication, therapy, diagnosis, sleep, medical conditions, and life stressors may need to be reassessed.
Home strategies can support professional treatment.
Helpful steps include:
Self-care practices such as regular sleep, healthy eating, physical activity, medication adherence, and watching for early warning signs can support recovery.
Do not try to manage severe depression alone.
No. Sadness is a normal emotion that usually changes with time and circumstances. Depression causes persistent symptoms that affect thinking, physical health, motivation, and daily functioning.
No. Depression is a medical and mental health condition, not a personal failure or lack of willpower.
Yes. Depression may cause fatigue, sleep problems, appetite changes, headaches, digestive discomfort, slowed movement, and other physical symptoms.
Yes. A person may continue working, smiling, or caring for others while experiencing significant depression internally.
Yes. Irritability, frustration, agitation, and anger can be symptoms of depression.
The length of an episode varies. Without treatment, symptoms may continue for months or longer. Treatment can reduce symptoms and shorten the episode.
Some symptoms may begin improving earlier, but full benefits often take time. The prescriber should explain when to follow up and when a medication adjustment may be appropriate.
The goal is to reduce symptoms and help the person function more like themselves. Emotional numbness can occur as a side effect and should be discussed with the prescriber.
Antidepressants do not usually cause addiction or intoxication. However, stopping suddenly may cause uncomfortable discontinuation symptoms.
Yes. Some people experience repeated episodes. Recognizing early warning signs and continuing recommended treatment may reduce relapse risk.
Exercise may support mood and overall health, but moderate or severe depression often requires professional treatment.
Alcohol may briefly reduce distress but often worsens sleep, mood, impulsivity, medication side effects, and suicide risk.
Yes. Perinatal or postpartum depression can occur during pregnancy or during the year after birth and should be treated promptly.
Severe depression may occasionally occur with hallucinations or strongly held false beliefs. This requires urgent professional assessment.
Consider asking:
Depression may be treated by a primary care provider or mental health professional.
Possible referrals include:
Depression is treatable, and many people recover fully from an episode. Some people experience recurring depression and require ongoing management.
Treatment can:
Even severe depression can respond to treatment. The treatment plan may need to be adjusted until the most effective approach is found.
Call 911 or go to the nearest emergency department if a person:
For suicidal thoughts, emotional crisis, or concern about someone’s safety in the United States, call or text 988 to reach the 988 Suicide & Crisis Lifeline. Support is available for suicidal crises, mental health distress, and substance-use concerns.
Seek urgent same-day mental health or medical care for:
Take all suicide-related statements seriously. Do not leave a person alone when there is immediate danger. Remove weapons, excess medication, and other lethal means when this can be done safely, and contact emergency services.
CALL 911
APNS does not provide emergency medical services. If you believe you are experiencing a medical emergency, including (but not limited to) chest pain, difficulty breathing, stroke symptoms, severe allergic reactions, anaphylaxis, uncontrolled bleeding, seizures, loss of consciousness, or any other potentially life-threatening condition, you are instructed to call 911 immediately or go immediately to the nearest emergency department.
Depression – National Institute of Mental Health
Provides information about depression symptoms, types, risk factors, treatment, and research.
Depression – NIMH Patient Guide
Explains diagnosis, psychotherapy, medication, brain-stimulation treatment, and how to find help.
Provides patient-friendly information about symptoms, diagnosis, treatment, and living with depression.
Antidepressants – NIH MedlinePlus
Explains antidepressant medications, side effects, and safe medication use.
Depression Screening – NIH MedlinePlus
Explains how depression screening tools are used and what results may mean.
988 Suicide & Crisis Lifeline – SAMHSA
Provides information about free crisis support available by calling or texting 988.
This guide is intended for educational purposes only and should not replace evaluation, diagnosis, psychotherapy, medication management, or emergency care from a qualified healthcare professional. Depression may occur with bipolar disorder, trauma-related conditions, anxiety, grief, substance use, medication side effects, hormonal conditions, neurological illness, or other medical problems requiring different treatment. Do not begin, stop, or change an antidepressant or other psychiatric medication without speaking with the prescriber. Contact a healthcare professional promptly for worsening depression, severe medication side effects, agitation, hallucinations, symptoms of mania, inability to perform basic self-care, or thoughts of self-harm. In the United States, call or text 988 for suicidal thoughts or a mental health crisis. Call 911 or go to the nearest emergency department when there is an active suicide attempt, immediate danger, serious overdose, severe self-injury, or inability to remain safe.
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