Predictors of progression from mild cognitive impairment to Alzheimer disease.
OBJECTIVE
To determine the occurrence of neuropsychiatric symptomatology and the relation to future development of Alzheimer disease (AD) in persons with and without mild cognitive impairment (MCI).


METHODS
We followed 185 persons with no cognitive impairment and 47 with MCI (amnestic and multidomain), ages 75 to 95, from the population-based Kungsholmen Project, Stockholm, Sweden, for 3 years. Three types of neuropsychiatric symptoms were assessed at baseline: mood-related depressive symptoms, motivation-related depressive symptoms, and anxiety-related symptomatology. AD at 3-year follow-up was diagnosed according to Diagnostic and Statistical Manual for Mental Disorders-III-R criteria.


RESULTS
Psychiatric symptoms occurred more frequently in persons with MCI (36.2% mood, 36.2% motivation, and 46.8% anxiety symptoms) than in cognitively intact elderly individuals (18.4% mood, 13.0% motivation, and 24.9% anxiety). Of persons with both MCI and anxiety symptoms, 83.3% developed AD over follow-up vs 6.1% of cognitively intact persons and 40.9% persons who had MCI without anxiety. Among persons with MCI, the 3-year risk of progressing to AD almost doubled with each anxiety symptom (relative risk [RR] = 1.8 [1.2 to 2.7] per symptom). Conversely, among cognitively intact subjects, only symptoms of depressive mood were related to AD development (RR = 1.9 [1.0 to 3.6] per symptom).


CONCLUSIONS
The predictive validity of mild cognitive impairment (MCI) for identifying future Alzheimer disease (AD) cases is improved in the presence of anxiety symptoms. Mood-related depressive symptoms (dysphoria, suicidal ideation, etc.) in preclinical AD might be related to the neuropathologic mechanism, as they appear preclinically in persons both with and without MCI.
Palmer
K
K
Aging Research Center, Karolinska Institutet, Stockholm, Sweden. katie.palmer@ki.se
Berger
A K
AK
Monastero
R
R
Winblad
B
B
Bäckman
L
L
Fratiglioni
L
L
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D001008:Anxiety Disorders / Q000175:diagnosis / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D015331:Cohort Studies; D003866:Depressive Disorder / Q000175:diagnosis / Q000523:psychology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D019964:Mood Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D009483:Neuropsychological Tests / Q000592:standards* / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D015995:Prevalence; D012307:Risk Factors