The Relationship Between Apathy,Depression And Domains Of Cognitive Function In People With Mild Cognitive Impairment

Background:Mild Cognitive Impairment(MCI)is a rather heterogeneous condition referring to a state of cognitive dysfunction between normal aging and dementia.Cognitive impairment and neuropsychiatric symptoms are frequently reported among MCI people.Apathy and depression are consistently described among the most common neuropsychiatric symptoms in MCI,which may accompany MCI and assist in identifying incipient dementia.At present,the relationship between depression and MCI has been largely discussed,however,apathy in MCI has been poorly understood,especially the occurrence of apathy,the difference between apathy and depression,and the correlation between apathy,depression and cognitive function.Objective:(1)To evaluate the validity and reliability of the Chinese version of the Apathy Evaluation Scale-Informant(AES-I)and the Lille Apathy Rating Scale-informant(LARS-i).(2)To explore the relationship between the apathy,depression and cognitive function in people with MCI:1)To compare the Chinese version of the AES-I and the LARS-i in Mild Cognitive Impairment informants.2)To describe the prevalence of apathy and depression in people with MCI.3)To describe the status of cognitive function of 4 types of MCI(MCI depressed-apathetic,MCI-apathetic,MCI-depressed,and MCI normal).Methods:A total of 199 MCI people and their informants were recruited from two communities in Beijing from December 2016 to August 2017 by convenience sampling to evaluate the validity and reliability of the Chinese version of the AES-I and the LARS-i.For further research,another 241 MCI people and their informants were recruited from December 2016 to March 2018.The correlation analysis and Receiver Operating Characteristic(ROC)curve were used to compare AES-I and LARS-i among Chinese MCI people.The LARS-i and the Geriatric Depression Scale(GDS,30 items)were employed to assess apathy and depression in people with MCI.The cognitive functions were evaluated with five specialized scales separately,including memory,language,attention,visual spatial function and executive function domains.Results:(1)For LARS-i,the content validity index was 1.00.Factor analysis indicated an 11-factor structure,the cumulative contribution rate was 65.84%,and three-factor structure was further established with the cumulative contribution rate of 50.10%.Cronbach's ? coefficient of the LARS-i was 0.83,and the items ranged 0.82?0.83.The test-retest reliability value was 0.80.For AES-I,the content validity index was 0.94.Exploratory factor analysis identified 4 common factors,which explained 55.28%of total variance.Cronbach's a coefficients were 0.81 for AES-I and 0.79?0.82 for each item.The test-retest coefficient were 0.76.The total score of LARS-i was correlated with AES-I score significantly(r=0.56,P<0.01).(2)The ROC curves of the AES-I and LARS-i are similar.The scores of the AES-I,LARS-i and the score of the Neuropsychiatric Inventory-Apathy Subscale(NPI-Apathy)were significantly related(r=0.346,0.450,P<0.01).The AES-I score was positively correlated with the score of the GDS-30(r=0.231,P<0.05),while the scores of the LARS-i and NPI-Apathy not(r=0.119,0.103,P>0.05).The scores of AES-I,LARS-i were negatively correlated with score of The Montreal Cognitive Assessment(MoCA)(r=-0.139,-0.128,P<0.01),whereas the NPI-Apathy had no correlation with MoCA score(r=-0.058,P>0.05).(3)Among 241 participants with MCI,79(32.8%)had apathy and 71(29.5%)had depression.Among 4 types of MCI(MCI depressed-apathetic,MCI-apathetic,MCI-depressed,and MCI normal),the MCI normal was the largest group(118,49.0%),followed by the group of MCI-apathetic(52,21.6%).(4)For the integral cognitive functions,the group of MCI depressed-apathetic were the worst,the group of MCI-apathetic were worse than the group of MCI-depressed,but there were no statistical differences.The differences of the language function of 4 types of MCI people was statistically significant(P<0.05).(5)Apathy severity was relevant to impaired performance in memory,language function(r=-0.183,-0.153,P<0.05),and depression severity was related with impaired performance in memory function(r=-0.190,P<0.05).Conclusion:The Chinese version of LARS-i and AES-I are reliable and valid instruments for measuring apathy in Chinese patients.The Chinese version of LARS-i is better than the AES-I scale in MCI informants in China.Prevalence of apathy was higher than depression in MCI people.The cognitive functions of the group of MCI depressed-apathetic were the worst,and the cognitive functions of the group of MCI-apathetic were worse than the group of MCI-depressed.Across all people,apathy severity correlated with impaired performance in memory and language,depression severity correlated with impaired performance in memory functioning.It is suggested that attention should be paid to the occurrence of apathy in MCI.The heterogeneity of cognitive functions in 4 types of MCI may provide new perspective for the differentiation between apathy and depression,and recommended that the emotion and cognition integrated together may provide better MCI interventions in clinical practices.