You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Treatment of choice in severe depression is - and explain in detail?
Make it very clear in your mind that the initial treatment of choice for severe depression is antidepressant medications.
ECT is the treatment of choice when severe depression is associated with a suicidal tendency or when severe depression is associated with psychotic features or when severe depression is refractory to antidepressants.