norby, an 18-year-old first-year university student, has missed almost all his classes during the past month. he spends most of his time in his bedroom and does not show or experience any interest or pleasure in any activity. he thinks his whole life has been a failure and blames himself for being a social misfit. norby is most likely suffering from:

a major depressive disorder

Explanation:

Depressive disorders are psychological mood, where an individual worries or think beyond the normal, especially sad thoughts from a very dampened mind. Depression starts in the mind and it's all emotional, they are various categories of them but when the situation is hard to come out from by the individual alone, and he would need a therapist then it's a major depressive disorder. What causes this is vast but all relates to what concerns people and their needs. This is what Norby is suffering from.