ECT can be good for a few people who have tried long-term medicinal treatment and not had it work. ECT is usually reserved for those to whom nothing else works. It can cause memory loss, even complete loss of memories. Since antidepressants have worked to some degree for you, then ECT would not be recommended for you. Depression can cause loss concentration, but so can antidepressants. It may be that you are resistant to the antidepressant you were taking so that it worked some but not enough. You may need to ask your doctor about increasing the dosage or trying another antidepressant. I took the medicine you are using and it did not work for me. I went back to sertraline at a higher dose and it works for me. Everybody is different in how they respond to medication. I tried Cymbalta and it made it worse, but others use it and have good results.