A FMRI Study On Implicit Emotion Associations Characteristic In Remitted Major Depressed Patients

Objective1.To investigate whether there are impaired implicit emotion associations recognition in remitted major depressed patients compared with healthy control.2.To definite brain functional imaging characteristic about implicit emotion associations recognition in remitted major depressed patients.MethodsSelecting 30 remitted major depressed patients with course of illness less than two years were as the research group who accord with diagnostic criteria of major depressive disorder in Diagnostic and statistical manual of mental disorders(DSM-5)and Hamilton Depression Rating Scale(HAMD)-17 were more than twenty-four when they came to the hospital and less than seven before they left the hospital.Selecting sex-age,literacy-matched healthy subjects with HAMD-17 were less than seven were as the control group.The research group and the control group performed the ST-IAT paradigm while fMRI images were collected.The average reaction times,D600(D600was calculated as the mean reaction time in incompatible blocks minus the mean reaction time in compatible blocks divided by the pooled standard deviation),error rate and the fMRI images were compared respectively.Results1.In remitted major depressed patients,the average reaction times of positive emotional pictures were(948.51?176.33)and the average reaction times of negative emotional pictures were(816.77?132.00);in healthy control subjects,he average reaction times of positive emotional pictures were(843.39?166.39)and the average reaction times of negative emotional pictures were(883.76?133.41).The average reaction times of positive emotional pictures were longer than the controls(F=91.123,P=0.000),while the average reaction times of negative emotional pictures were shorter than the controls(F=61.417,P=0.000).2.In remitted major depressed patients,the D600s of negative emotional pictures were(0.088?0.032)and the D600s of positive emotional pictures were(0.054?0.019);in healthy control subjects,The D600s of negative emotional pictures were(0.057?0.017)and The D600s of positive emotional pictures were(0.053?0.016).The D600s of remitted major depressed patients during negative emotional pictures stimulation were higher than the controls(t=-4.439,P=0.000),but there were no difference between the two groups during positive emotional pictures stimulation(t=0.525,P=0.603)and in remitted major depressed patients,the D600s of negative emotional pictures were higher than positive emotional pictures(t=-4.501,P=0.000),but there were no difference between negative emotional pictures and negative emotional pictures in healthy control subjects(t=0.630,P=0.536).3.In remitted major depressed patients,the error rate of positive emotional pictures-positive was 8.29%,the error rate of negative emotional pictures-negative was 4.00%,the error rate of positive emotional pictures-negative was 4.84%,the error rate of negative emotional pictures-positive was 4.73%;in healthy control subjects,the error rate of positive emotional pictures-positive was 2.26%,the error rate of negative emotional pictures-negative was 5.34%,the error rate of positive emotional pictures-negative was 1.46%,the error rate of negative emotional pictures-positive was 6.40%.The error rate of positive emotional pictures-positive in remitted major depressed patients were higher than the controls(x~2=4.106,P=0.043),while there werenodifferencebetweenthetwogroupsinotheremotional pictures-positive/negative(P>0.05).4.Activated brain function regions of negative emotional pictures stimulation in remitted major depressed patients higher than healthy control subjects included dorsolateral frontal gyrus on left(Z=4.30,P=0.000227),orbital frontal gyrus on left(Z=3.99,P=0.000461),orbitofrontal gyrus on left(Z=3.79,P=0.00898)and pars triangularis on left(Z=3.70,P=0.041);but there were no difference between the two groups in activated brain function regions of positive emotional pictures stimulation(P>0.05).Conclusion1.Slow identification of positive emotional pictures,while higher identification of negative emotional pictures in remitted major depressed patients compared with healthy control subjects.2.There is a implicit cognition bias toward negative emotional pictures in emitted major depressed patients compared with healthy control subjects.3.Activated brain function regions of negative emotional pictures stimulation in remitted major depressed patients higher than healthy control subjects include dorsolateral frontal gyrus on left,orbital frontal gyrus on left,orbitofrontal gyrus on left and pars triangularis on left,which lead to the implicit cognition bias toward negative emotional pictures.