Major Depressive Disorder, also known as major depression or clinical depression, is the most common depressive disorder. Students with major depression usually have a severe and persistent low mood or feelings of sadness or hopelessness that last at least two weeks. However, major depressive episodes often last much longer. Untreated, they can go on for months or years. Depression is different for every person. Other potential symptoms include: Sleeping too much or trouble sleeping Overeating or loss of appetite and weight gain or loss Difficulty concentrating or memory problems Feeling tired Apathy, or loss of interest in activities you used to enjoy Moving slowly or seeming agitated Low self-esteem, feeling bad about yourself, or feeling like a failure Feeling indecisive Thoughts of death, self-harm, or suicide