The most common signs & effects of depression are:

• Persistent sadness, emptiness, or hopelessness

• Loss of interest in activities once enjoyed

• Changes in sleep or appetite

• Difficulty concentrating or making decisions

• Feelings of worthlessness or excessive guilt

• Low energy or fatigue most of the time

To be diagnosed with depression, these symptoms must be present for at least two weeks and represent a significant change from a person's usual functioning.