Depression ranges in seriousness from mild, temporary episodes of sadness to severe, persistent depression. Clinical depression is the more-severe form of depression, also known as major depression or major depressive disorder. It isn’t the same as depression caused by a loss, such as the death of a loved one, or a medical condition, such as a thyroid disorder.

To diagnose clinical depression, many doctors use the symptom criteria for major depressive disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association.

Signs and symptoms of clinical depression may include:

• Feelings of sadness, tearfulness, emptiness or hopelessness
• Angry outbursts, irritability or frustration, even over small matters
• Loss of interest or pleasure in most or all normal activities, such as sex, hobbies or sports
• Sleep disturbances, including insomnia or sleeping too much
• Tiredness and lack of energy, so even…