Research suggests that depression is linked to chemical imbalances in the brain. Depression may also run in families.

Depression that starts in later life is often associated with difficult life events or situations, such as:

  • The death of a relative or friend
  • The loss of a job or retirement
  • Social isolation from a range of causes (such as limited mobility or hearing loss)
  • A hospitalization or placement in a nursing facility
  • Chronic illness, disability, or other stresses

Medical problems that are associated with a higher risk of depression are:

  • Thyroid disorders
  • Some vitamin deficiencies
  • Alcohol or drug abuse 
  • Heart disease 
  • Diabetes 
  • Side effects of medications (such as drugs for high blood pressure or Parkinson’s disease, sedatives, corticosteroids, and hormones)
  • Cancer and other major illnesses
  • Long-term pain
  • Difficulty getting restful sleep

Usually, a combination of factors is involved.


Last Updated September 2020