Major depressive disorder

1. Treated

1.1. Medication

1.1.1. Antidepressant medications

1.1.1.1. Atypical antidepressants

1.1.1.2. Selective Serotonin Reuptake Inhibitors (SSRIs)

1.1.1.2.1. Fluoxetine

1.1.1.2.2. Citalopram

1.1.1.3. Tricyclic Antidepressants (TCAs)

1.2. Therapy

1.2.1. Psychotherapy

1.2.1.1. Talking with a therapist about condition and related issues

1.2.2. Cognitive behavioral therapy

1.2.3. Interpersonal therapy

1.2.4. Group therapy

1.3. Lifestyle changes

1.4. Eating right

1.5. Avoiding alcohol and certain processed foods

1.6. Getting plenty of exercise

1.7. Sleeping well

2. Cause

2.1. Alcohol or drug abuse

2.2. Sickness

2.2.1. Cancer

2.2.2. Hypothyroidism

2.3. Side effects of some drugs

2.3.1. Steroids

2.4. Stress

2.5. Genetic disorder

2.6. Changes in the balance of hormones

3. Symptoms

3.1. Often feel sad or irritable

3.2. Changing in appetite

3.3. Having trouble falling asleep

3.4. Feelings of restlessness

3.5. Unusually tired 

3.6. Feeling of worthless or guilty

3.7. Having difficulty concentrating, thinking, or making decisions

3.8. Thinking about harming themself or committing suicide

3.9. Less interested in activities they once enjoyed