Depression is a bio-chemical illness, just like diabetes. It is a condition where the brain chemistry gets out of balance, and that causes both physical symptoms and emotional symptoms. It affects how one feels, thinks, and acts. There are several types of depression. Some of the more common forms include:

  • Major
  • Dysthymia
  • Atypial

They vary in length and severity, but share common symptoms. There is also a distinction between:

  • Endogenous depression, caused by low availability of neurotransmitters, and is usually genetic
  • Situational depression, caused by external life stressors


  • Sadness
  • Feelings of worthlessness
  • Difficulty concentrating
  • Loss of interest
  • Short-term memory problems
  • Difficulty sleeping or sleeping excessively
  • Suicidal ideation

When to Screen

  • Patients with cancer
  • With a past hx of depression
  • > 60 years of age
  • With heart failure
  • Within 3 months of acute cardiac event
  • With chronic pain
  • First-degree biologic relative with history of depression
  • Two or more chronic diseases
  • Obesity
  • Chronic pain (e.g., backache, headache)
  • Impoverished home environment
  • Financial strain
  • Experiencing major life changes
  • Pregnant or postpartum
  • Socially isolated
  • Multiple vague symptoms (e.g., gastrointestinal, cardiovascular, neurologic)
  • Fatigue or sleep disturbance
  • Substance abuse, such as alcohol or street drugs
  • Loss of interest in sexual activity