A Complete Guide to Depression
This article provides an overview of depression, including its types, symptoms, diagnosis, and treatments.
Depression is a common type of mental health condition. Depression can negatively affect how you feel, interact with others, and engage with the world around you.
For people with depression, feelings of sadness linger and intensify to the point that they interfere with their ability to function as usual, which may then intensify depression symptoms.
Depression is a common condition. The National Center for Health Statistics estimates that over 4% of adults ages 18 and over in the United States regularly experienced feelings of depression from 2019–2023.
- Major depression: Also known as major depressive disorder, this type involves symptoms of depression that interfere with a person’s usual activities, sometimes for weeks at a time.
- Persistent depressive disorder: Previously known as dysthymia, symptoms of this condition are less severe than major depression but may last for years at a time.
- Prenatal depression and postpartum depression: Prenatal depression begins during pregnancy, while postpartum depression symptoms occur after childbirth.
- Seasonal depression: Commonly known as seasonal affective disorder, symptoms often flare up during late fall and winter, getting better in spring and summer.
Depression may also occur with other conditions, such as bipolar disorder. People with certain types of bipolar disorder may have periods of depression mixed with periods of mania.
Learn more about the types of depression.
Typical signs and symptoms of depression can include one or more of the following:
- sadness or melancholy
- feelings of worthlessness or guilt
- feelings of hopelessness and despair
- loss of interest in previously enjoyed activities
- low energy levels and fatigue
- aches, pains, headaches, or digestive problems
- anger or irritability
- difficulties with memory, concentration, or making decisions
- sleep irregularities, such as insomnia or a desire to sleep all the time (hypersomnia)
- changes in appetite that lead to weight gain or weight loss
Everyone can experience some of these symptoms, such as sadness, from time to time. Depression symptoms do not go away by themselves or get better with time.
Depression can cause such intense symptoms that you may develop thoughts of self-harm, harming others, or suicide. If you or someone you know is experiencing severe depression symptoms, seek immediate medical attention.
Learn about 7 symptoms to never ignore if you have depression.
If someone you know is at immediate risk of harming themselves or others, or at risk of suicide:
- Even if it’s tough, ask, “Are you considering suicide?”
- Listen without judgment.
- Call 911 or your local emergency number.
- Stay with them until emergency services arrive.
- Try to remove any weapons, medications, or other potentially harmful items.
If you or someone you know is having suicidal thoughts, contact the 988 Suicide and Crisis Lifeline:
- Call or text 988
- Chat online
This service is available 24/7.
The exact cause of depression isn’t clear, but
Possible causes and risk factors include:
- imbalances of certain chemicals in the brain, such as serotonin and dopamine
- genetic factors, such as low levels of a protein called brain-derived neurotrophic factor that influences learning and memory
- chronic health conditions, including diabetes and cancer
- inflammation affecting many areas of the body, including the gut and brain
- situational or environmental factors that cause trauma or stress, such as the loss of a loved one or job
To diagnose depression, your doctor will begin by asking you about your symptoms, evaluating your medical history, and performing a physical examination. Then, they will try to determine whether you meet certain criteria for a depression diagnosis.
Many healthcare professionals follow the
To be diagnosed with depression, a person must be experiencing at least five or more of the following criteria daily, for most of the day, and for at least two weeks in a row:
- depressed mood
- loss of pleasure or interest in most activities
- a significant increase or decrease in appetite and unintentional weight loss or gain
- sleep disturbances, such as sleeping too much or too little
- psychomotor changes, such as agitation, restlessness, or slow thinking or movement
- fatigue or low energy
- feeling worthless or excessive, illogical guilt
- difficulty thinking, concentrating, or making decisions
- recurrent thoughts of death or suicide
A depression diagnosis requires that a person must be experiencing either depressed mood or loss of interest in addition to four of the other listed symptoms. In addition, these symptoms need to be occurring daily, for most of the day, or for at least two weeks in a row.
If your doctor determines that you might be experiencing symptoms of depression, they may refer you to a psychiatrist for further evaluation.
Read our depression appointment guide to find out more about what you may want to ask or what you may be asked at the doctor’s office.
The overall treatment goal for people with depression is to feel better and live functional and productive lives.
Your treatment plan may include a combination of medications, therapy, and lifestyle changes.
Antidepressants treat depression by affecting brain chemicals called neurotransmitters, including serotonin, norepinephrine, and dopamine. Neurotransmitters function within the areas of the brain that regulate emotions and mood.
- selective serotonin reuptake inhibitors, such as fluoxetine (Prozac) and sertraline (Zoloft)
- serotonin-norepinephrine reuptake inhibitors, such as venlafaxine (Effexor)
- tricyclic antidepressants, such as imipramine (Tofranil)
- monoamine oxidase inhibitors, such as isocarboxazid (Marplan) and selegiline (Emsam)
Learn more about depression medications.
The National Alliance on Mental Illness (NAMI) notes that several types of therapy can fall into the psychotherapy category, including:
- Cognitive behavioral therapy (CBT): CBT may help people with depression change their thought processes and beliefs. This can positively impact the way they think.
- Interpersonal therapy: This therapy can help people with depression improve their relationships with others.
- Family-focused therapy: In this therapy, people with depression and their families are helped to understand the nature of depression and find ways to manage and navigate it.
Learn 3 psychiatrist tips for people with depression.
In the past, people whose depression did not respond to more conventional treatments may have been considered candidates for electroconvulsive therapy (ECT). In ECT, electric currents are sent throughout the brain.
Learn more about treatment options for mild, moderate, and severe depression.
Some people with depression develop treatment-resistant depression. This is defined as depression that’s resistant to
People with treatment-resistant depression may need to add additional medications — like lithium (Esklaith) — to their treatment plan to find relief.
In 2019, the
Learn more about whether depression is curable.
According to the American Psychiatric Association, certain lifestyle changes may reduce depression symptoms, including:
- getting regular physical activity
- getting consistent, quality sleep
- eating a nutrient-dense diet
- avoiding alcohol or limiting your intake
Learn about 5 foods to avoid if you have depression.
Support is available for people with depression and their loved ones.
NAMI provides links to virtual and in-person support groups where people can share their experiences and talk with others who may be in the same situation.
Your doctor may also be able to help you find local and virtual support resources.
Depression is a common mental health condition that can result in persistent feelings of sadness and even physical symptoms. Though the condition can be serious, many treatments are available to help people with depression manage their symptoms.
Talk with your doctor if you believe you may have depression. They can discuss a management plan that’s right for you.