1. Depression can be inherited i.e., the chance of a person having the condition increases considerably if one or more family members have it.

  2. Environmental factors like the death of a parent can cause a depressive episode.

  3. Physical illnesses like cancer, heart disease and Parkinson's disease may be associated with depression.

  4. Depression can also be a side effect of certain drugs used to treat hypertension.

  5. Some people have personality traits that make them more susceptible to depression. These people view themselves as losers and have a negative attitude towards themselves.