Tau accumulation increases the susceptibility to effective seizures of electroconvulsive therapy.

Electroconvulsive therapy (ECT) is a very valuable treatment for mood disorders. While previous studies have examined predictors of ECT responsiveness, there is a scarcity of neuroimaging studies examining these predictors. In previous studies, it has been reported that epilepsy is significantly more common in patients with Alzheimer's disease, and it has been suggested that tau accumulation is related to the susceptibility to seizures. Positron emission tomography (PET) with florzolotau (18 F) ([18F]PM-PBB3) allows accurate quantification of tau in the brain cortex. We therefore performed tau PET with florzolotau (18 F) in 14 patients with mood disorders undergoing ECT to determine whether there is a relationship between tau accumulation and susceptibility to ECT. As a result, we found that the more tau accumulates, the more likely it is to produce effective seizures in ECT. Although our study has some limitations, it is suggested that ECT would be the first choice for treatment of depression associated with degenerative pathology such as Alzheimer's disease because tau accumulation might enhance the therapeutic efficacy of ECT.