Earlier quoted context omitted.
The other credible theory is that by damaging your brain cells, they can no longer fire in ways that regulate your mood towards depression.
Got some references for that? I ask because ECT seems to upregulate trophic factors, rather than downregulating them. Some sort of hippocampal injury does seem like it could explain memory-related side effects, but it apparently doesn't actually happen (e.g., https://jamanetwork.com/journals/jamapsychiatry/fullarticle/... )
"ECT damage is easy to find if you look for it" https://www.nature.com/articles/35002188