Depression is a mental illness marked by feelings of profound sadness and lack of interest in activities. It is a persistent low mood that interferes with the ability to function and appreciate things in life. It may cause a wide range of symptoms, both physical and emotional. It can last for weeks, months, or years. People with depression rarely recover without treatment.


The exact cause of depression is not known. It may be due to a certain type of brain chemistry. While the exact cause is not clearly established, there are several factors that play a role in depression.

The Brain

Brain Man Face
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Depression is more common in females. There are a range of factors that may increase your risk of depression. Examples include:

  • Having a family history of depression
  • Spouse with depression
  • Previous episode of depression
  • Hormonal changes
  • Chronic illness
  • Other conditions related to mental health, such as anxiety, drug abuse, insomnia, and a personality disorder
  • History of traumatic brain injury
  • History of concussion in teenagers
  • History of drug or alcohol use disorder
  • Domestic violence
  • History of child abuse and neglect or sexual abuse
  • A parent who is on military deployment
  • Obesity
  • History of bullying
  • History of self-harm as a teenager, with or without suicidal intent
  • Emotional or social factors such as:
    • Little or no social support
    • Negative thought patterns and beliefs
    • Low self-esteem
    • Lack of personal control over circumstances
    • Feelings of helplessness


Depression can differ from person to person. Some people have only a few symptoms, while others have many.

Symptoms can change over time and may include:

  • Persistent feelings of sadness, anxiety, or emptiness
  • Hopelessness
  • Feeling guilty, worthless, or helpless
  • Feeling tired
  • Restlessness or irritability
  • Trouble sleeping, waking up too early, or oversleeping
  • Loss of interest in hobbies and activities
  • Trouble concentrating, remembering, or making decisions
  • Loss of interest in sex
  • Eating more or less than usual
  • Weight gain or weight loss
  • Thoughts of death or suicide with or without suicide attempts
  • Physical symptoms that defy standard diagnosis and do not respond well to medical treatments


There is no blood test or diagnostic test for depression. You will be asked about your symptoms and medical history. Depression is usually diagnosed based on the duration, frequency, number, and nature of your symptoms. Special attention will be given to:

  • Alcohol and drug use
  • Thoughts of death or suicide
  • Family members who have or have had depression
  • Sleep patterns
  • Previous episodes of depression

Specific mental health exams may be done. This will help the doctor get detailed information about your speech, thoughts, memory, and mood. A physical exam and other tests can help rule out other causes.


Treatment may involve the use of medication and/or psychotherapy.

Severe depression can require hospital care, especially if you are at risk of hurting yourself or others.


Antidepressant medications

Antidepressant medications may be most effective in people with severe depression. These medications can take 2-6 weeks to reach their maximum effectiveness. There are many different types of medications to treat depression. You will work with your doctor to find the medication that benefits you the most and has the least side effects.


Psychotherapy for depression consists of various types of counseling. These include cognitive-behavior therapy (CBT) , interpersonal therapy, psychodynamic therapy, or a combination of these. Therapy is designed to help you cope with difficulties in relationships, change negative thinking and behavior patterns, and resolve difficult feelings.

Diet and exercise

Dietary changes

Research suggests that diets high in tryptophan and certain B vitamins may be helpful. There is also mixed evidence that omega-3 fatty acids may reduce symptoms.

If you want to take supplements or change your diet, talk to your doctor first.

Dietary supplements and herbal therapy

The herb St. John's wort may be an effective alternative to standard medications with fewer side effects. However, St. John's wort may reduce the effectiveness of many drugs, such as antidepressants, birth control pills, blood thinners, and other medications. It is important that you talk to your doctor before trying any herb.

There is also some evidence that dehydroepiandrosterone (DHEA), a hormone that is available as a dietary supplement, may help some people.


A regular exercise program has been shown to relieve some of the symptoms. It should play a large role in the overall management of depression.


Electroconvulsive therapy (ect)

ECT is the use of an electric stimulus to produce a generalized seizure. It may be used in people with severe or life-threatening depression. ECT is also used for people who cannot take or do not respond to medication. It is considered a safe and effective procedure.

Vagus nerve stimulation (vns)

VNS is used as therapy for depression when multiple trials of medication do not work. A pacemaker-like device stimulates the vagus nerve in the neck.

Vagus Nerve

Vagus Nerve
Stimulation of the vagus nerve (yellow) at the neck is a depression therapy option.
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Transcranial magnetic stimulation (tms)

TMS involves the application of low-frequency magnetic pulses to the brain. The change in electrical field stimulates nerves. There are a number of studies that show the benefits of TMS for the treatment of depression. It may be used if you have not gotten better with medications and psychotherapy.

Other treatment options

Bright light therapy

Bright light therapy involves exposure to high levels of light from a special light box that has a screen on it. The light shifts natural rhythm of the sleep cycle. It is generally used in combination with other treatments and can take 1-3 weeks for results to be seen.

Sleep deprivation therapy

Sleep deprivation therapy involves is a behavioral program where sleep is greatly decreased over a few consecutive nights. It is designed as a short-term treatment that produces rapid improvement in mood.


Strategies to reduce your chances of depression include:

  • Being aware of your personal risk factors
  • Having a psychiatric evaluation and psychotherapy if needed
  • Developing social supports
  • Learning stress management techniques
  • Exercising regularly
  • Not abusing alcohol or drugs
  • Getting adequate sleep, rest, and recreation
  • Eating healthy food, including fruits, vegetables, and whole grains