What Is the Number One Cause of Depression?

There is no single cause of depression, which is an imbalance in brain chemistry. Risk factors for depression include genetics, personality, environment, brain changes, physical illness, lifestyle, and medications.

Depression (also called major depressive disorder or clinical depression) is a mood disorder that adversely affects how a person thinks, feels, acts, and deals with daily activities. It can cause a marked decrease in a person’s ability to enjoy their life.

Sadness and grief share some characteristics with depression, but they are not the same as depression.

Symptoms of depression may include: 

• Persistent sadness, anxiety, or “empty” mood
• Feelings of guilt, worthlessness, or helplessness
• Loss of interest or pleasure in hobbies and activities that were once enjoyed
• Feelings of hopelessness or pessimism
• Difficulty concentrating, remembering, or making decisions
• Difficulty sleeping or sleeping too much
• Irritability
• Loss of energy or increased fatigue
• Moving or talking more slowly
• Restlessness or difficulty sitting still
• Changes in appetite and/or weight 
• Aches or pains, headaches, cramps, or digestive problems without a clear physical cause and/or that do not ease even with treatment
• Thoughts of death or suicide, or suicide attempts
  • If you or someone you know are in crisis, call the toll-free National Suicide Prevention Lifeline at 1-800-273-TALK (8255), available 24 hours a day, 7 days a week. The service is available to anyone. All calls are confidential.

Depression usually does not have a single cause. Clinical depression is an imbalance in brain chemistry, but what causes this to occur is usually a combination of genetic, biological, environmental, and psychological factors.

Risk factors for developing depression include:

• Genetics
  • Depression often runs in families
  • Having a sibling or a parent who suffers from depression increases the risk of someone becoming depressed
• Personality
  • People who are pessimistic, easily overwhelmed, tend to worry a lot, are perfectionists, are very sensitive to personal criticism, or have low self-esteem are more likely to suffer from depression
• Environmental factors
  • Exposure to neglect, violence, poverty, or other trauma
  • Post-traumatic stress disorder (PTSD)
• Brain changes
  • Differences in neurotransmitters or hormones, as well as activity in parts of the brain can contribute to symptoms of depression
• Certain serious physical illnesses 
  • Diabetes
  • Cancer
  • Heart disease
  • Parkinson’s disease
  • Sleep disturbances
  • Chronic pain
  • Anxiety
  • Attention-deficit hyperactivity disorder (ADHD) 
• Lifestyle factors
  • Major life changes
  • Relationship problems
  • Lack of exercise and proper nutrition
  • Poor sleep habits
  • Working too much
  • Drug and alcohol abuse
• Certain medications

Even severe cases of depression can be treated, though it may take time and trial and error to find the right treatment for each patient. 

Treatments for depression include: 

• Medications
  • Antidepressants 
  • Mood stabilizers
  • Antipsychotic medications
• Psychotherapies
  • Cognitive-behavioral therapy (CBT)
  • Interpersonal therapy (IPT)
  • Problem-solving therapy
• Brain stimulation therapies
  • Electroconvulsive therapy (ECT) 
  • Transcranial magnetic stimulation (rTMS) 
  • Vagus nerve stimulation (VNS)
• Light therapy
  • Uses a lightbox to expose a person to full-spectrum light in an effort to regulate the hormone melatonin
• Alternative approaches 
  • Acupuncture
  • Meditation
  • Nutrition