Signs and symptoms of depression (or a depressive episode) include:

• Lasting sad, anxious, or empty mood
• Feelings of hopelessness or pessimism
• Feelings of guilt, worthlessness, or helplessness
• Loss of interest or pleasure in activities once enjoyed, including sex
• Decreased energy, a feeling of fatigue or of being "slowed down"
• Difficulty concentrating, remembering, making decisions
• Restlessness or irritability
• Sleeping too much, or can't sleep
• Change in appetite and/or unintended weight loss or gain
• Chronic pain or other persistent bodily symptoms that are not caused by physical illness or injury
• Thoughts of death or suicide, or suicide attempts

A depressive episode is diagnosed if 5 or more of these symptoms last most of the day, nearly every day, for a period of 2 weeks or longer.