Effects Of N-3 Polyunsaturated Fatty Acids On Cognitive Function In Elderly Patients With Major Depressive Episode

Objective:To investigate the effect of n-3 polyunsaturated fatty acids on cognitive function in elderly patients with Major depressive episodeMethods:According to the Inclusion Criteria and exclusion criteria,81 elderly patients with major depression episode treated in Qingdao Mental Health Center from June 2020 to August 2021 were selected as the object of study.Randomly divided into two groups:fish oil group(duloxetine combined with omega-3 fatty acid fish oil capsule)and placebo group(duloxetine combined with vitamin E soft capsule).At the time of admission(T0)and at the end of the second week(that is,before taking fish oil or placebo,phase T1)、at the end of the fourth week(i.e.the second week of taking fish oil or placebo,phase T2)、at the end of the sixth week(i.e.the fourth week of taking fish oil or placebo,stage T3)、at the end of the 8th week(i.e.at the end of the 6th week when taking fish oil or placebo,phase T4)、and at the end of the 10th week(i.e.at the end of the 8th week when taking fish oil or placebo,phase T5)17 items of Hamilton Depression scale were used to evaluate the condition of depression.The cognitive function of the patients was assessed by perceived Deficit Questionnaire for Depression(PDQ-D),Trail Making Test A(TMT-A),Digit Symbol Substitution Test(DSST)and digit span test(DST)at phase T1、T3 and T5.According to the inclusion criteria,40 healthy elderly patients were selected as the healthy control group.The cognitive function of T0 case group and healthy control group were compared.The scores of depression scale,cognitive function,efficacy and adverse reactions at different time points in fish oil group and placebo group were compared,and the cognitive functions of fish oil group and healthy control group were comparedResults:1.At phase T0,the scores of perceived Deficit Questionnaire for Depression and Trail Making Test A in the case group were significantly higher than those in the healthy control group(P<0.001).The scores of cognitive function related scales such as digital symbol conversion test and digit span test were lower than those in the healthy control group,and the difference was statistically significant(P<0.001).2.Comparison of 17-HAMD between fish oil group and Placebo group:the score of HAMD-17 in both groups showed a downward trend.The correction results of Greenhouse-Geisser showed that there was significant difference in HAMD score at different time points,fish oil group(F=259.938,P<0.001)and placebo group(F=288.431,P<0.001).There was no significant difference between fish oil group and placebo group in T1,T2 and T3 stages of treatment.The 17-HAMD score of fish oil group was lower than that of placebo group in T4 and T5 stages3.Comparison of cognitive function between fish oil group and placebo group:after 8weeks of intervention with fish oil capsule or placebo capsule,the scores of PDQ-D and TMT-A in fish oil group and placebo group were lower than those before intervention,while the scores of DST-back in reverse order,DSST and DST-order back were higher than those before intervention,and the difference was statistically significant(all P<0.001).Comparison between groups,After 8 weeks of intervention with fish oil capsule or placebo capsule,the PDQ-D score in the fish oil group was lower than that in the placebo group,and the DST-order back score in the placebo group was higher than that in the placebo group,but there was no significant difference in the scores of TMT-A,DSST and DST-back in reverse order.4.At T5 stage,the scores of PDQ-D and TMT-A in the fish oil group were higher than those in the healthy control group,while the scores of DST-back in reverse order,DSST and DST-order back in the fish oil group were lower than those in the healthy control group.5.The clinical effective rate of fish oil group was higher than that of placebo group,and the difference was statistically significant(P=0.030).The total incidence of adverse reactions and the incidence of individual adverse reactions were compared between the two groups.χ~2test showed that there was no significant difference between the two groups by Fisher correction(P>0.05).Conclusion:1.N-3 Polyunsaturated fatty acids,as adjunctive therapy for antidepressant treatment,are effective,safe and have few adverse reactions for elderly patients with major depression.2.N-3 Polyunsaturated fatty acids can improve the subjective cognition and short-term memory of elderly patients with major depression more obviously,but short-term(8 weeks)application can’t restore the cognitive function of elderly patients with major depression to healthy old age level.