I'm wondering if the blank mind/feeling mentally disengaged is like the psychomotor retardation described in some people with depression. I recently had a SPECT scan showing hyperactive medial pfc and thalamus. The same areas in the depression study by Dr. Liston for the subtype with high anhedonia and psychomotor retardation. If so, maybe I just have a strange form of depression. My next step is likely to find a TMS provider who will work with my specific situation .
I haven't seen the studies you mention, but I think it is thought that psychomotor retardation is supposed to predict response to Electroconvulsive therapy. However I doubt that the blank mind can be understood as a type of psychomotor retardation. Nonetheless I will try ECT in the future, probably when I get the chance to try kappa-opioid-antagonism and it doesn't work. I'm very much in the same place as you, including the diagnostic
When it comes to TMS and depression I think you should not have too high expectations. Although it is approved for depression the standard protocol seems to be widely regarded as disappointing and I think I read that patients with anhedonia are the ones who do not
benefit from it. Generally TMS has been tried for for many things in the last decades, but it isn't really establised for anything.