Karen is a college student who has experienced moderate feelings of sadness and worthlessness for over 2 years. Most of the time, she still goes to class and meets her other obligations. Occasionally, however, her depressive symptoms intensify. When this occurs, she stops going to class, isolates herself, and even experiences suicidal thoughts. Karen could be diagnosed with: Group of answer choices dissociative identity disorder. major depressive disorder and generalized anxiety disorder. double depression. persistent depressive disorder.