Old worries and new anxieties: behavioral symptoms and mild cognitive impairment in a population study.

OBJECTIVE: To disentangle the complex associations of depression and anxiety with mild cognitive impairment (MCI) at the population level. We examined subgroups of anxiety symptoms and depression symptom profiles in relation to MCI, which we defined using both cognitive and functional approaches.
METHODS: We used an epidemiologic, cross-sectional study with an age-stratified, random, population-based sample of 1,982 individuals aged 65 years and over. Three definitions of MCI were used: 1) a purely cognitive classification into amnestic and nonamnestic MCI, 2) a combined cognitive-functional definition by International Working Group (IWG) criteria, and 3) a purely functional definition by the Clinical Dementia Rating (CDR) of 0.5. Three depression profiles were identified by factor analysis of the modified Center for Epidemiological Studies-Depression Scale: core mood, self-esteem/interpersonal, and apathy/neurovegetative profiles. Three anxiety groups, chronic mild worry, chronic severe anxiety, and recent-onset anxiety, were based on screening questions.
RESULTS: Recent-onset anxiety was associated with MCI by nonamnestic and IWG criteria, chronic severe anxiety was associated with MCI by all definitions, and chronic mild worry was associated with none. Of the depression profiles, the core mood profile was associated with CDR-defined MCI, the apathy/neurovegetative profile was associated with MCI by amnestic, IWG, and CDR definitions, and the self-esteem/interpersonal profile was associated with none.
CONCLUSION: In this population-based sample, subgroups with different anxiety and depression profiles had different relationships with cognitive and functional definitions of MCI. Anxiety, depression, and MCI are all multidimensional entities, interacting in complex ways that may shed light on underlying neural mechanisms.