Metacognitive Performance And Underlying Brain Structures In Major Depression Disorders

Objective: Metacognition is the ability to monitor and control an individual’s mental processes and contributes to effective internal decisionmaking in a range of contexts.Impaired metacognition may indicate poor mental health.However,research on the metacognitive ability and underlying brain structures of Major Depression Disorder(MDD)patients are relatively rare and the conclusive is unclear.This study investigated metacognition performance in MDD patients using a post-decision confidence rating paradigm,and further explore metacognition-related brain neural biomarkers in MDD patients.Methods: Seventy-nine MDD patients(age 18.89±3.41,63 females)and 76 healthy controls(age 19.73±2.92,52 females)performed a perceptual metacognitive task with a retrospective confidence assessment following perceptual decision-making.The severity of depression and anxiety symptoms was also assessed in MDD patients using the Hamilton Depression Scale(HAMD)and Hamilton Anxiety Scale(HAMA).The metacognitive ability of each participant was calculated based on task data.Furthermore,T1 structural images of the brains of all subjects were acquired by scanning with a 3.0T MRI.Voxelbased Morphometry(VBM)was used to compare the whole brain and Region of Interest(ROI)grey matter volumes of MDD and healthy control subjects,and the correlation with clinical symptoms was further explored.Results: The behavioral results show that 1)compared to healthy controls,metacognitive sensitivity and metacognitive efficiency were significantly reduced in MDD patients.Furthermore,MDD patients demonstrated a significant negative metacognitive bias in performance when compared to healthy controls.2)In the MDD group,metacognitive sensitivity was significantly negatively correlated with scores of the HAMD and HAMA(r=-0.246,p=0.029;r=-0.317,p=0.004),metacognitive efficiency was significantly negatively correlated with the scores of HAMA(r=-0.341,p=0.002),metacognitive bias was significantly negatively correlated with HAMD scores(r=-0.239,p=0.034).The VBM analysis showed that 1)compared to healthy control,the gray matter volumes of the left medial prefrontal cortex(Brodmann10,BA10),left dorsolateral prefrontal lobe(BA46),left middle temporal gyrus,left insula,left fusiform,left postcentral gyrus and right superior temporal gyrus was significantly reduced in MDD patients.2)In the MDD group,gray matter volume in the left prefrontal cortex,right middle temporal gyrus,right superior temporal gyrus,and left fusiform were significantly positively correlated with metacognitive sensitivity(r=0.227～0.284,p<0.05),while gray matter volume in the left middle temporal gyrus was significantly positively correlated with metacognitive efficiency(r=0.225,p=0.046).3)ROI analysis further confirmed that compared to healthy controls,the gray matter volume in the frontal lobes(posterior medial frontal cortex(MNI:-2,30,38),left dorsolateral prefrontal(MNI:-50,24,28),right prefrontal(MNI: 32,50,8),and right dorsolateral prefrontal(MNI: 8,42,44))had significantly reduced in MDD patients.Metacognitive sensitivity was significantly positively correlated with gray matter volume in the posterior medial frontal cortex(MNI:-2,30,38)(r=0.306,p=0.006)and right dorsolateral prefrontal(MNI: 8,42,44)(r=0.282,p=0.012)in MDD patients.Conclusions: MDD patients exhibit impaired metacognitive ability,the degree of impaired metacognitive ability correlates with clinical anxiety symptoms and severity of depressive symptoms.Decreased gray matter volume in the prefrontal,temporal lobe and fusiform may be one of the brain’s neurobiomarkers of impaired metacognition in adult depression.