Cognitive functioning in the general population: Factor structure and association with mental disorders-The neuropsychological test battery of the mental health module of the German Health Interview and Examination Survey for Adults (DEGS1-MH)

The assessment of cognitive function in the German National Cohort (NAKO) - Associations of demographics and psychiatric symptoms with cognitive test performance

OBJECTIVES

To describe the cognitive test battery of the German National Cohort (NAKO), a population-based mega cohort of 205,000 randomly selected participants, and to examine associations with demographic variables and selected psychiatric and neurological conditions.

METHODS

Initial data from 96,401 participants providing data on the cognitive performance measured by a brief cognitive test battery (12-word list recall task, semantic fluency, Stroop test, digit span backwards) was examined. Test results were summarised in cognitive domain scores using exploratory and confirmatory factor analyses. Associations with sociodemographic and psychiatric factors were analysed using linear regression and generalised additive models.

RESULTS

Cognitive test results were best represented by two domain scores reflecting memory and executive functions. Lower cognitive functions were associated with increasing age and male sex. Higher education and absence of childhood trauma were associated with better cognitive function. Moderate to severe levels of anxiety and depression, and a history of stroke, were related to lower cognitive function with a stronger effect on executive function as compared to memory. Some associations with cognition differed by German language proficiency.

CONCLUSIONS

The NAKO cognitive test battery and the derived cognitive domain scores for memory and executive function are sensitive measures of cognition.

The C Factor: Cognitive dysfunction as a transdiagnostic dimension in psychopathology

Research into cognitive functions across psychological disorders suggests that cognitive deficiencies may be present across multiple disorders, potentially pointing to a transdiagnostic phenomenon. More recently, a single dimension model of psychopathology, the p factor, has been proposed, in which cognitive deficits are thought to be an intrinsic construct, assumed to be transdiagnostic. However, no systematic investigation to date tested this hypothesis. The aim of the present study was to systematically review meta-analyses to assess the hypothesis that the C factor (cognitive dysfunction) is transdiagnostic in psychopathology and review potential moderators that may account for such a phenomenon. We conducted a systematic review of meta-analyses examining cognitive function across all disorders for which data were available. Included meta-analyses (n = 82), comprising 97 clinical samples, yielded 1,055 effect sizes. Twelve major disorders/categories (e.g., bipolar disorder, substance use disorders) were included, comprising 29 distinct clinical entities (e.g., euthymic bipolar disorder; alcohol use disorder). Results show that all disorders reviewed are associated with underperformance across cognitive domains, supporting the hypothesis that the C factor (or cognitive dysfunction) is a transdiagnostic factor related to p. To examine moderators that may explain or contribute to c, we first consider important interpretative limitations of neuropsychological data in psychopathology. More crucially, we review oft-neglected motivational and emotional transdiagnostic constructs of p, as prominent contributing constructs to the C factor. These constructs are offered as a roadmap for future research examining these constructs related to p, that contribute, and may account for cognitive dysfunctions in psychopathology.

Cognitive functioning in the general population: Factor structure and association with mental disorders-The neuropsychological test battery of the mental health module of the German Health Interview and Examination Survey for Adults (DEGS1-MH)

The objective of this study is to obtain population level data about cognitive functions and their association with mental disorders. We here report factor analytic and psychometric findings of a neuropsychological test battery and examine the association of current and past mental disorders with cognitive function in a large nationwide population-based sample of 18- to 79-year-old adults in Germany (n = 3,667) participating in the mental health module of the German Health Interview and Examination Survey for Adults 2008-2011. Confirmatory factor analysis confirmed verbal memory and executive function factors. Older age was strongly associated with lower verbal memory and executive function and with higher vocabulary scores. After adjustment for age, sex, and education, rather modest decrements were found for verbal memory (β = -.118, p = .002) and executive functions (β = -.191, p < .001) in participants with any current mental disorder (n = 442) compared to those without (n = 3,201). Small decrements in memory (β = -.064, p = .031) and executive function (β = -.111, p < .001) were found in participants with any mental disorder in the last 12 months but not in those with past (fully or partially remitted) mental disorders, compared to participants without a history of mental disorder. More fine-grained analyses of these data will investigate the complex interplay between cognition, health behaviors, and specific mental and somatic diseases.