Major Depressive Disorder Symptoms. Part of the series: Mental Health & Behavior. Symptoms of major depressive disorder are similar to, but much more intense than, normal depression, and they include lack of energy, fatigue, eating disorders, insomnia, inability to concentrate, hopelessness, helplessness and lack of motivation to do anything. Understand major depressive disorder, and how it differs from normal depression, with information from a licensed mental health counselor in this free video on mental health conditions. Read more: http://www.ehow.com/video_4791046_major-depressive-disorder-symptoms.html