Final answer:
Based on the described behavior, Janet most likely has bipolar disorder, characterized by dramatic shifts between manic and depressive episodes, affecting day-to-day functionality.
Step-by-step explanation:
The behavior described in the question, where Janet maintains the same position for hours but on rare occasions will suddenly become excited and run around the room in circles, suggests that she may be experiencing mood swings. Based on the information provided, Janet appears to have bipolar disorder. Bipolar disorder is marked by dramatic shifts in energy and mood, which can affect an individual's ability to carry out day-to-day tasks. In contrast, major depressive disorder is characterized by a long-term, intensely depressed mood and a loss of enjoyment in activities, while schizophrenia involves symptoms such as delusions and disorganized thinking, and generalized anxiety disorder is characterized by long-lasting excessive worry. Therefore, the sudden and sporadic changes in Janet's behavior most closely align with the manic and depressive episodes experienced in bipolar disorder.