It must be difficult suffering from depression that has not responded to antidepressant medications. You report positive results from Electro-Convulsive Therapy (ECT). ECT may be safely continued on a "maintainance" basis. It is not uncommon for people to respond better to antidepressant medications after ECT. You may also find it helpful to combine ECT and antidepressant medications with cognitive-behavioral therapy or interpersonal therapy. I urge you to discuss your concerns further with your treating physician/psychiatrist.