Abstract
ECT is unique and one of the most effective somatic therapy in psychiatry; however, biomarkers for ECT outperforming clinical indication have not been established. Near Infrared Spectroscopy (NIRS) is a non-invasive method to measure blood flow in the human brain; in Japan, this method has been identified as a tool for an adjunct to the diagnosis of psychiatric disorders. To examine whether NIRS can be useful as a biomarker for ECT, we investigated the changes in the regional cerebral blood flow (rCBF) in the prefrontal cortex (PFC) using NIRS in comparison between schizophrenia and mood disorders. The rCBF caused by bilateral ECT at the PFC increased during ECT and there was a left dominant asymmetric alteration of rCBF for schizophrenia. The asymmetric alteration appeared not to be state-dependent, rather trait-dependent. Because the asymmetry alteration was negatively correlated with the period of illness for schizophrenia, but not with any other clinical data, the left dominant asymmetric hemodynamic response might be a marker of schizophrenia, especially in the early stages. These results indicate the possibility that the ECT-induced hemodynamic response using NIRS might be useful for adjunct estimation of diagnosis and symptoms and further study is needed.
