a Major Depressive Episode is defined by a period of at least 2 weeks during which there is either depressed mood or the loss of interest or pleasure in nearly all activities. In children and adolescents, the mood may be irritable rather than sad. This is accompanied by additional symptoms such as changes in appetite, weight, sleep, or psychomotor activity, decreased energy, feelings of worthlessness or guilt, difficulty concentrating or making decisions, and recurrent thoughts of death or suicide.