A physician examines a severely depressed 75-year-old woman. The woman relates that she feels so low that she cannot enjoy anything in her life, and that even winning the state lottery would not make her feel any better. The best description of this patient's mood is

This severely depressed 75-year-old woman is showing anhedonia, the inability to feel pleasure, a characteristic of severe depression. Euphoric mood is an elated mood, while euthymic mood is a normal mood, with no significant depression or elevation. Dysphoric mood is a subjectively unpleasant feeling. Labile moods (mood swings) are alterations between elevated and dysphoric moods.