Depression
Depression is a mental health condition that can cause persistent low mood, loss of interest, changes in sleep or appetite, low energy, difficulty concentrating, guilt, hopelessness, physical symptoms, and thoughts of death or suicide. It is treatable, but it can be serious and disabling.
What depression is
Depression is more than ordinary sadness. It is a health condition that changes mood, motivation, sleep, appetite, concentration, movement, body sensations, and how a person experiences the future. Major depressive disorder is one diagnosis, but depressive symptoms can also occur with grief, trauma, chronic illness, substance use, hormonal changes, medication effects, and other mental health conditions.
Symptoms
Common symptoms include persistent sadness, emptiness, irritability, loss of interest or pleasure, fatigue, sleep changes, appetite or weight changes, slowed or restless movement, difficulty concentrating, feelings of worthlessness or guilt, physical aches, and thoughts of death or suicide. Some people mainly notice numbness, anger, anxiety, or body symptoms rather than obvious sadness.
Diagnosis
Diagnosis is based on symptoms, duration, impairment, history, and ruling out other explanations when needed. Clinicians may ask about mood, sleep, appetite, concentration, substance use, medications, trauma, medical conditions, manic symptoms, and suicide risk. Screening questionnaires can help identify symptoms, but they do not replace a full clinical assessment.
Causes and risk factors
Depression does not have one simple cause. Risk can be shaped by genetics, brain circuits, stress, trauma, grief, isolation, chronic illness, pain, sleep disruption, substance use, hormones, poverty, discrimination, medications, and life events. Biology and environment interact; depression is not a character flaw or a failure of willpower.
Brain and body
Depression involves mood systems, reward processing, stress hormones, sleep rhythms, inflammation, pain pathways, and thinking patterns. Neurotransmitters such as serotonin, norepinephrine, dopamine, glutamate, and GABA are part of the story, but depression is not accurately explained as only a chemical imbalance of one molecule.
Treatment options
Treatment can include psychotherapy, antidepressant medicines, treatment of medical contributors, exercise or activity planning, sleep support, social support, reduced substance use, and safety planning. For severe, persistent, or urgent cases, options may include intensive outpatient care, hospitalization, electroconvulsive therapy, transcranial magnetic stimulation, ketamine-related treatments, or other specialist care.
Psychotherapy and skills
Psychotherapies can help people understand patterns, build coping skills, reconnect with valued activities, process grief or trauma, change unhelpful thoughts, improve relationships, and reduce relapse risk. Different approaches include cognitive behavioral therapy, interpersonal therapy, behavioral activation, problem-solving therapy, and other evidence-based methods.
Medicines and time
Antidepressants can help some people, especially when symptoms are moderate, severe, recurrent, or paired with anxiety or other conditions. They usually take time to show benefit and may have side effects. Choosing, adjusting, or stopping medicine should be guided by a clinician because response varies and abrupt changes can cause problems.
Safety and suicide risk
Depression can increase suicide risk, especially when hopelessness, agitation, substance use, severe anxiety, prior attempts, isolation, or access to lethal means are present. Thoughts of suicide or self-harm should be taken seriously. Crisis support, emergency care, reducing access to lethal means, and involving trusted people can be lifesaving.
Why it matters
Depression matters because it is common, disabling, treatable, and often hidden. It affects health, work, school, relationships, sleep, pain, and risk of other illness. Understanding depression helps reduce stigma, encourages earlier care, and makes room for both biological treatment and practical human support.