***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: CONTEXT Prospect i ve studies have established an association between depressive symptoms and risk of dementia , but how depressive symptoms change during the evolution of dementia is uncertain . OBJECTIVE To test the hypothesis that depressive symptoms increase during the prodromal phase of Alzheimer disease ( AD ) . DESIGN Prospect i ve cohort study . PARTICIPANTS AND SETTING For up to 13 years , 917 older Catholic nuns , priests , and monks without dementia at study onset completed annual clinical evaluations that included administration of the 10-item Center for Epidemiologic Studies Depression Scale and clinical classification of mild cognitive impairment and AD . MAIN OUTCOME MEASURE Change in depressive symptoms reported on the Center for Epidemiologic Studies Depression Scale . RESULTS At baseline , participants reported a mean ( SD ) of 1.0 ( 1.5 ) depressive symptoms  . Those who developed AD ( n = 190 ) showed no increase in depressive symptoms before the diagnosis was made , and this finding was not modified by age , sex , education , memory complaints , vascular burden , or personality . There was no systematic change in depressive symptoms after the AD diagnosis , although symptoms tended to decrease in women relative to men and in those with a higher premorbid level of openness and a lower premorbid level of agreeableness . Among those without cognitive impairment at baseline , depressive symptoms did not increase in those who subsequently developed mild cognitive impairment . CONCLUSION We found no evidence of an increase in depressive symptoms during the prodromal phase of AD BACKGROUND Subjects with a mild cognitive impairment ( MCI ) have a memory impairment beyond that expected for age and education yet are not demented . These subjects are becoming the focus of many prediction studies and early intervention trials . OBJECTIVE To characterize clinical ly subjects with MCI  cross-sectionally and longitudinally . DESIGN A prospect i ve , longitudinal inception cohort . SETTING General community clinic . PARTICIPANTS A sample of 76 consecutively evaluated subjects with MCI were compared with 234 healthy control subjects and 106 patients with mild Alzheimer disease ( AD ) , all from a community setting as part of the Mayo Clinic Alzheimer 's Disease Center/Alzheimer 's Disease Patient Registry , Rochester , Minn. MAIN OUTCOME MEASURES The 3 groups of individuals were compared on demographic factors and measures of cognitive function including the  Mini-Mental State Examination , Wechsler Adult Intelligence Scale-Revised , Wechsler Memory Scale-Revised , Dementia Rating Scale , Free and Cued Selective Reminding Test , and Auditory Verbal Learning Test .  Clinical classifications of dementia and AD were determined according to the Diagnostic and Statistical Manual of Mental Disorders , Revised Third Edition and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer 's Disease and Related Disorders Association criteria , respectively . RESULTS The primary distinction between control subjects and subjects with MCI was in the area of memory , while other cognitive functions were comparable . However , when the subjects with MCI were compared with the patients with very mild AD , memory performance was similar , but patients with AD were more impaired in other cognitive domains as well . Longitudinal performance demonstrated that the subjects with MCI declined at a rate greater than that of the controls but less rapidly than the patients with mild AD . CONCLUSIONS Patients who meet the criteria for MCI can be differentiated from healthy control subjects and those with very mild AD . They appear to constitute a clinical entity that can be characterized for treatment interventions Background : Apathy is a common symptom in various neuropsychiatric diseases including mild cognitive impairment ( MCI ) and dementia . Apathy may be associated with an increased risk of cognitive decline . The objective of this study was to investigate if apathy predicts the progression from MCI to Alzheimer ’s disease ( AD ) . Methods : The Alzheimer ’s Disease Neuroimaging Initiative is a prospect i ve multicentre cohort study . At baseline , 397 patients with MCI without major depression were included .  Clinical data and the Geriatric Depression Scale  at baseline were used . Apathy was defined based on the 3 apathy items of the 15-item  Geriatric Depression Scale . The main outcome measure was the association of apathy with progression from MCI to AD . Results : During an average follow-up of 2.7 years ( SD 1.0 ) , 166 ( 41.8 % ) patients progressed to AD . The presence of symptoms of apathy without symptoms of depressive affect increased the risk of progression from MCI to AD ( hazard ratio = 1.85 , 95 % CI = 1.09–3.15 ) . Apathy in the context of symptoms of depressive affect or symptoms of depressive affect alone , without apathy , did not increase the risk of progression to AD . Conclusions : Symptoms of apathy , but not symptoms of depressive affect , increase the risk of progression from MCI to AD . Apathy in the context of symptoms of depressive affect does not increase this risk . Symptoms of apathy and depression have differential effects on cognitive decline Studies on humans show that depressive disorder is associated with an increased risk of developing cognitive dysfunction , and animal studies suggest that antidepressants may have neuroprotective abilities . On the basis of these observations , it was hypothesized that treatment with antidepressants may decrease the risk of developing dementia in patients with depression . We investigated whether continued treatment with antidepressants is associated with a decreased rate of dementia in a population of patients discharged from psychiatric healthcare service with a diagnosis of depression . We used register data on all prescribed  antidepressants in all patients discharged from psychiatric healthcare service with a diagnosis of depression and with subsequent diagnoses of dementia in Denmark from 1995 to 2005 . A total of 37 658 patients with a diagnosis of depression at their first psychiatric contact and who were exposed to antidepressants after discharge were included in the study . A total of 2007 patients ( 5.3 % ) were subsequently diagnosed with dementia of any kind . The rate of dementia decreased during periods of two or more prescriptions of older antidepressants compared with the period of only one prescription of older antidepressants [ relative risk (RR)=0.83 ( 95 % confidence interval (CI)=0.70–0.98 ) ] . This finding was replicated with Alzheimer ’s disease as the outcome [ RR=0.66 ( 95 % CI=0.47–0.94 ) ] but not with dementia of other kinds as the outcome [ RR=0.88 ( 95 % CI=0.73–1.06 ) ] . In contrast , during periods of continued use of selective serotonin reuptake inhibitors or newer nonselective serotonin reuptake inhibitors , the rate of dementia was not decreased , regardless of the subtype of dementia . It was concluded that continued long-term treatment with older antidepressants is associated with a reduced rate of dementia in patients treated in psychiatric healthcare setting s , whereas continued treatment with other kinds of antidepressants is not . Method ological reasons for these findings can not be excluded because of the nonr and omized nature of data Identification of potentially modifiable risk factors for cognitive deterioration is important . We conducted a prospect i ve study of 5,607 subjects with normal cognition and 2,500 subjects with mild cognitive impairment ( MCI ) at 30 Alzheimer 's Disease Centers in the Unites States between 2005 and 2011 .  Cox regression was used to determine whether depression predicted transition from normal to MCI , or MCI to Alzheimer 's disease ( AD ) . Over an average of 3.3 visits , 15 % of normal subjects transitioned to MCI ( 62/1000 per year ) , while 38 % of MCI subjects transitioned to AD ( 146/1000 per year ) . At baseline , 22 % of participants had recent ( within the last two years ) depression defined by clinician judgment ; 9 % and 17 % were depressed using the Geriatric Depression Scale ( GDS score ≥5 ) and the Neuropsychiatric Inventory Question naire ( NPI-Q ) , respectively . At baseline , depressed subjects performed significantly worse on cognitive tests . Those always depressed throughout follow-up had an increased risk for progression from normal to MCI ( RR = 2.35 ; 95 % CI 1.93 - 3.08 ) versus never depressed . Normal subjects , identified as depressed at first visit but subsequently improved , were found to have lower risk of progression ( RR 1.40 ( 1.01 - 1.95 ) ) . The ' always depressed ' had only a modest increased risk of progression from MCI to AD ( RR = 1.21 ( 1.00 - 1.46 ) . Results were similar using time-dependent variables for depression or when defining depression via the GDS or NPI-Q. We found no effect of earlier depression ( > 2 years past ) . The effect of recent depression did not differ by antidepressant treatment , APOE4 allele status , or type of MCI . In conclusion , late-life depression is a strong risk factor for normal subjects progressing to MCI Objective : To examine risk factors for  mild cognitive impairment ( MCI ) and progression to dementia in a prospect i ve community-based study of subjects aged 65 years and over . Methods : 6892 participants who were over 65 and without dementia were recruited from a population -based cohort in three French cities . Cognitive performance , clinical diagnosis of dementia , and clinical and environmental risk factors were evaluated at baseline and 2-year and 4-year follow-ups . Results : 42 % of the population were classified as having MCI at baseline . After adjustment for confounding with logistic regression models , men and women classified as having MCI were more likely to have depressive symptomatology and to be taking anticholinergic drugs .  Men were also more likely to have a higher body mass index , diabetes and stroke , whereas women were more likely to have poor subjective health , to be disabled , to be socially isolated , and to suffer from insomnia . The principal adjusted risk factors for men for progression from MCI to dementia in descending order were ApoE4 allele ( OR = 3.2 , 95 % CI 1.7 to 5.7 ) , stroke ( OR = 2.8 , 95 % CI 1.2 to 6.9 ) , low level of education ( OR = 2.3 , 95 % CI 1.3 to 4.1 ) , loss of Instrumental Activities of Daily Living ( IADL ) ( OR = 2.2 , 95 % CI 1.1 to 4.5 ) and age ( OR = 1.2 , 95 % CI 1.1 to 1.2 ) . In women , progression is best predicted by IADL loss ( OR = 3.5 , 95 % CI 2.1 to 5.9 ) , ApoE4 allele ( OR = 2.3 , 95 % CI 1.4 to 4.0 ) , low level of education ( OR = 2.2 , 95 % CI 1.3 to 3.6 ) , sub clinical depression ( OR = 2.0 , 95 % CI 1.1 to 3.6 ) , use of anticholinergic drugs ( OR = 1.8 , 95 % CI 1.0 to 3.0 ) and age ( OR = 1.1 , 95 % CI 1.1 to 1.2 ) . Conclusions : Men and women have different risk profiles for both MCI and progression to dementia . Intervention programmes should focus principally on risk of stroke in men and depressive symptomatology and use of anticholinergic medication in women OBJECTIVE The authors conducted a prospect i ve cohort study to estimate the risk of incident mild cognitive impairment in cognitively normal elderly ( aged ≥70 years ) individuals with or without neuropsychiatric symptoms at baseline . The research was conducted in the setting of the population -based Mayo Clinic Study of Aging . METHOD A classification of normal cognitive aging , mild cognitive impairment , and dementia was adjudicated by an expert consensus panel based on published criteria . Hazard ratios and 95 % confidence intervals were computed using Cox proportional hazards model , with age as a time scale . Baseline Neuropsychiatric Inventory Question naire data were available for 1,587 cognitively normal persons who underwent at least one follow-up visit . RESULTS The cohort was followed to incident mild cognitive impairment ( N=365 ) or censoring variables ( N=179 ) for a median of 5 years . Agitation ( hazard ratio=3.06 , 95 % CI=1.89 - 4.93 ) , apathy ( hazard ratio=2.26 , 95 % CI=1.49 - 3.41 ) , anxiety ( hazard ratio=1.87 , 95 % CI=1.28 - 2.73 ) , irritability ( hazard ratio=1.84 , 95 % CI=1.31 - 2.58 ) , and depression ( hazard ratio=1.63 , 95 % CI=1.23 - 2.16 ) , observed initially , increased risk for later mild cognitive impairment . Delusion and hallucination did not . A secondary analysis , limited in significance by the small number of study participants , showed that euphoria , disinhibition , and nighttime behaviors were significant predictors of nonamnestic mild cognitive impairment but not amnestic mild cognitive impairment . By contrast , 
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DISCUSSION Our results provide additional evidence that depressive symptoms determine an additive risk effect to the progression to dementia in subjects with MCI .
The comorbidity between depression and cognitive impairment can be an intervention target for prevention of dementia in MCI subjects .