Functional MRI Study Of Gender-related Differences Of Emotional Memory In Major Depressive Disorder

Backgrounds and Objectives Depression is a kind of mood disease which ishazard to human health and emotional behavior and characterized by the depressed stateof mood, which is a mental illness syndrome in clinical. There are gender-differences inthe incidence and prevalence in depression and ratio of male and female isapproximately1:2. It is found that there are gender-related differences in structure andfunction of the normal brain regions with neuroimaging studies. Whether the genderdifference existed in MDD need further study. There are a few reports about genderdifference in depression’s cerebral structure and resting state functional magneticresonance imaging at home and abroad, but few studies with the task state functionalmagnetic resonance imaging. In this study, related neural mechanisms of depression inemotional memory were explored with mixed design fMRI of event-related and block,and provided a new insight in gender specific cerebral mechanisms.Materials and Methods Thirty-nine subjects with depression,(16males, mean38.4±2.57years;23females, mean37.2±2.32years) and forty-four healthy controls (23males, mean22.43±0.31years;21females, mean21.85±0.34years) were involved inthis study. One hundred and twenty pictures were used in this experiment. Bothencoding and retrieval period were involved in the experimental process. Behavioralperformance was recorded and functional MR data were acquired via3.0T MRI scanner.MATLAB7.12, AFNI and SPSS13.0were used for statistical analysis of fMRI andbehavioral data.Results (1) The behavioral results indicated that there is no significant gender difference in response to negative photos in group of depression. The correct responseto neutral photos was the worst in females with MDD and great difference was foundbetween the male and female with MDD (P<0.05). There is not significant genderdifference in behavioral study of the fear，neutral in healthy controls.(2) Tasking-state fMRI results suggested that more activated brain regions were foundduring the transient enhancement effect in female with MDD, which include the leftinferior frontal gyrus triangle, calcarine, middle occipital gyrus; right angular gyrus,caudate, superior temporal gyrus, and posterior cingulate cortex. However, moreactivated brain regions were found during the sustained enhancement effect in malewith MDD, which include the left middle frontal gyrus, caudate, insula, right middletemporal gyrus and middle cingulate. The transient enhancement effect was moresignificant in group of female with MDD than healthy female. The sustainedenhancement effect was more significant in group of male with MDD than healthymale.Conclusions (1) The memory cognitive function declined significantly in MDD, butmemory enhancement effect remains. The neutral event memory significantlydecreased in women with MDD, but emotion enhanced effect increase, whileenhanced effect in men is weaker in MDD than healthy controls.(2) Emotion-related brain regions activated in MDD existence of gender differences.Female transient effect relative enhancement, mainly related to the occipital parietalcortex. The male sustained effect relative strengthened, mainly related to the frontalcingulate and frontal inferior oper portion.