Symptom criteria: (1) loss of interest, no sense of enjoyment; (2) loss of energy or fatigue; (3) psychomotor retardation or agitation; (4) low self-esteem, self-blame, or feelings of guilt; (5) difficulty in association or reduced intuitive thinking; (6) recurrent thoughts of death or suicidal or self-injurious behavior; (7) sleep disorders, such as insomnia, early awakening, or excessive sleep; (8) decreased appetite or significant weight loss; (9) decreased sexual desire.