The Comparison Of Cognitive Functions Between First-episode And Recurrent Depression

ObjectivesTo study the impact factors and the difference of cognitive function between first-episode depression and recurrent depression,which could provide evidence for clinical early intervention.Methods91 patients with depression(43 first-episode depression and 48 recurrent depression)and 45 healthy volunteers participated in this study.All the patients were measured with Hamilton Depression Scale-17(HAMD- 17), P300(the amplitude of P3 and N2,the latency of P3 and N2),Wechsler Memory Scale(WMS-long-term memory,short-term memory,immediate memory,memory quotient)and Wisconsin Card Sorting Test(WCST- total errors,preservative errors,preservative responses,completed categories) before and after 8-week medicine treatment of SSRIs.The control group were measured with HAMD-17,P300,WMS and WCST once.Results1.There were significant differences in all items but immediate memory and N2 amplitude between untreated first-episode group and control group. All the items of untreated recurrent group were worse than the control(P＜0.01).The completed categories and items of WMS in first-episode group were higher than recurrent group(P＜0.01). 2.There were significant differences in all the other items between first-episode group and control after treatment(P＜0.05)except long-term memory,immediate memory,completed categories,the amplitude of P3 and N2.Almost all the items in recurrent group were worse than control(P＜0.05),except the immediate memory.But between first-episode group and recurrent group,there were significant difference in all items except the amplitude of N2(P＜0.05).3.Significant improvement was found in HAMD₁₇and all items of cognitive function after treatment in first-episode group and recurrent group. Decrease were found in HAMD₁₇,total errors,preservative errors, preservative responses,the latency of P3 and N2 and increase in other items(P＜0.01).4.There were correlations between all items and age except completed categories,the amplitude of N2 in two depression group and short-term memory in recurrent group.No correlations were found between the course of depression and immediate memory,completed categories,the amplitude of N2,total errors in recurrent group.Negtive correlations were found between the the course of depression and the long-term memory,short-term memory, memory quotient,the amplitude of P3.While positive correlations extisted between the course and preservative errors,preservative responses,total errors in first-episode group,the latency of P3.So as to the recurrence frequency,it correlated with all the items of WMS and the amplitude of P3 negtively,while with total errors,preservative errors,preservative responses, the latency of P3 positively.And no correlations were found between the recurrence frequency and the amplitude of N2,the latency of N2,completed categories.Conclusion1.There are mnemic and executive disfunctions in patients with depression,and these disfunctions in recurrent depression is more severe than in first-episode depression.2.The mnemic and executive disfunctions can be improved by medication.The improvement of cognitive functions in first-episode depression is better than in recurrent depression.3.There were more decreased mnemic and executive dis functions in the depression patients with long duration and multi-onset.