According to the U.S. National Institute of Mental Health, symptoms of depression include:

• Being persistently sad or anxious（持续存在的悲哀或焦虑）,
• Feeling hopeless（深感无望）,
• Feelings of guilt, worthlessness, helplessness（负罪感、无用论、无助感）,
• Loss of interest or pleasure in hobbies and activities（缺乏兴趣）,
• Lack of energy and fatigue（易疲劳）,
• Difficulty concentrating, remembering, making decisions（注意力难集中、记忆力衰减和决策困难）
• Difficulty sleeping or oversleeping（失眠或贪睡）,
• Changes in appetite or weight（食欲或体重改变）,
• Thoughts of death or suicide or suicide attempts（自杀念头或企图）,
• Restlessness, irritability（不安、易怒）.