Alterations of the amplitude of low-frequency fluctuations in treatment-resistant and treatment-response depression: A resting-state fMRI study

BackgroundPatients with treatment-resistant depression (TRD) and those with treatment-response depression (TSD) respond to antidepressants differently and previous studies have commonly reported different brain networks in resistant and nonresistant patients. Using the amplitude of low-frequency fluctuations (ALFF) approach, we explored ALFF values of the brain regions in TRD and TSD patients at resting state to test the hypothesis of the different brain networks in TRD and TSD patients.MethodsEighteen TRD patients, 17 TSD patients and 17 gender-, age-, and education-matched healthy subjects participated in the resting-state fMRI scans.ResultsThere are widespread differences in ALFF values among TRD patients, TSD patients and healthy subjects throughout the cerebellum, the visual recognition circuit (middle temporal gyrus, middle/inferior occipital gyrus and fusiform), the hate circuit (putamen), the default circuit (ACC and medial frontal gyrus) and the risk/action circuit (inferior frontal gyrus). The differences in brain circuits between the TRD and TSD patients are mainly in the cerebellum, the visual recognition circuit and the default circuit.ConclusionsThe affected brain circuits of TRD patients might be partly different from those of TSD patients.

► TRD and TSD respond to drugs differently and may have different brain networks. ► ALFF method could detect functional alterations in patients and controls. ► The brain networks between the TRD and TSD patients might be partly different. ► ALFF method could be a new tool for the detection of neural activity.