Final answer:
ECT is used today primarily to treat severe depression that hasn't responded to other treatments, not for schizophrenia, dissociative amnesia-related memory loss, or untreatable personality disorders.
Step-by-step explanation:
Today, electroconvulsive therapy (ECT) is primarily used to treat severe depression that has been unresponsive to other treatments. Depression is a mental disorder characterized by symptoms such as a severely depressed mood, loss of enjoyment in activities, changes in appetite and sleep, and possible sui_cidal thoughts. Despite other forms of treatment such as psychotherapy, deep-brain stimulation, and various prescription medications, some cases of depression remain resistant, and ECT has been found to be effective in such instances. Therefore, ECT today is not commonly indicated for patients with schizophrenia who stop taking their medications, memory loss as a result of dissociative amnesia, or untreatable personality disorders.