I experienced both. The unilateral ECT was not as effective with me since I was so severe. It could have. Undiagnosed thyroid disease can cause depression or prevent your medications from working properly. Lately, I have been having delusions and losing track of time.
Delusions are very complex.
They can originate from schizophrenia type illnesses, or take that form because of possible trauma. My relief from depression was less than one week. The memory loss is still very much a problem. I have lost two months totally and pieces of my life are gone. I still suffer from severe depression and, of course, I am badgered to get a recharge which I refuse.