Social connection is associated with better health, including reduced risk of dementia. Personality traits are also linked to cognitive outcomes; neuroticism is associated with increased risk of dementia. Personality traits and social connection are also associated with each other. Taken together, evidence suggests the potential impacts of neuroticism and social connection on cognitive outcomes may be linked. However, very few studies have simultaneously examined the relationships between personality, social connection and health.

We tested the association between neuroticism and cognitive measures while exploring the potential mediating roles of aspects of social connection (loneliness and social isolation).

We conducted a cross-sectional study with a secondary analysis of the Canadian Longitudinal Study on Aging (CLSA) Comprehensive Cohort, a sample of Canadians aged 45 to 85 years at baseline. We used only self-reported data collected at the first follow-up, between 2015 and 2018 (n= 27,765). We used structural equation modelling to assess the association between neuroticism (exposure) and six cognitive measures (Rey Auditory Verbal Learning Test immediate recall and delayed recall, Animal Fluency Test, Mental Alternation Test, Controlled Oral Word Association Test and Stroop Test interference ratio), with direct and indirect effects (through social isolation and loneliness). We included age, education and hearing in the models and stratified all analyses by sex, females (n= 14,133) and males (n=13,632).

We found positive, statistically significant associations between neuroticism and social isolation (p<0.05) and loneliness (p<0.05), for both males and females. We also found inverse, statistically significant associations between neuroticism and all cognitive measures (p<0.05), except the Stroop Test interference ratio. In these models, there was consistent evidence of indirect effects (through social isolation and loneliness) and, in some cases, evidence of direct effects. We found sex differences in the model results.

Our findings suggest that the association between neuroticism and cognitive outcomes may be mediated by aspects of social connection and differ by sex. Understanding if and how modifiable risk factors mediate the association between personality and cognitive outcomes would help develop and target intervention strategies that improve social connection and brain health.

Cognitively healthy individuals who complete a neuropsychological test battery can obtain very low scores. These very low scores are not likely indicative of cognitive impairment but are rather considered spuriously low scores. The expected number of low scores varies based on number and type of neuropsychological tests. Typically, base rates have been determined from normative samples, which could differ from samples seen in clinical settings. The current study reports on base rates of spuriously low cognitive scores in older adults presenting to a memory clinic who were diagnosed with subjective cognitive impairment after interprofessional assessment and information from collateral informants ruled out objective cognitive impairment.

Base rates of spuriously low scores for a neuropsychological battery of 12 scores were based on 92 cognitively healthy older adults presenting to a specialist memory clinic (M(age) = 61.00, SD = 12.00; M(edu) = 12.00, SD = 2.74). Crawford’s Monte Carlo simulation algorithm was used to estimate multivariate base rates by calculating the percentage of cognitively healthy memory clinic patients who produced age and education normed scores at or below the 5th percentile. The following tests were used to produce the 12 scores: block design, digit span backwards, and coding from the WAIS-IV; logical memory I and II from the WMS-IV; immediate and delayed memory scores from the California Verbal Learning Test Second Edition short form; immediate and delayed memory scores from the Brief Visuospatial Memory Test Revised; category switching, letter number sequencing, and inhibition switching from the Delis Kaplin Executive Functioning System.

An estimated 33.58% of the cognitively healthy memory clinic population would have one or more low scores (5th percentile cutoff),14.7% would have two or more low scores, 6.55% would have three or more, 2.94% would have four or more, and 1.31% percent would have 5 or more very low scores due to chance.

Determining base rates of spuriously low scores on a neuropsychological battery in a clinical sample of referred older adults with subjective memory complaints could assist in the diagnostic process. By understanding base rates of clinical samples, clinicians can use empirical data to adjust for expected low scores rather than using conventional corrections (such as 1/20 test scores expected to be low). In a memory clinic sample, three or more low test scores out of 12 is expected to be relatively rare in those who were later determined to have no objective evidence of cognitive impairment based on interprofessional assessment. Understanding normal frequency of low scores will prevent undue conclusions of cognitive impairment which will minimize false positives in diagnosis.

Depressive symptomatology has long been shown to be associated with the onset of dementia, though the exact form and directionality of this association remains unclear. While much research has gone into confirming this link, there has been little investigation into the effects of depression on dementia progression after diagnosis. The aim of this study is to investigate the relationship between depressive symptomatology and cognitive and behavioural decline over the following year.

In a Rural and Remote Memory Clinic, 375 patients consecutively diagnosed with mild cognitive impairment (MCI), Alzheimer’s Disease (AD), or non-AD dementia completed the Center for Epidemiological Studies Depression Scale (CES-D) at first visit and one-year follow-up to assess depressive symptomatology. The same cohort were evaluated for cognitive and behavioural decline through the completion of five clinical tests performed at the first visit and at one-year follow-up. Cognitive decline was assessed using the Mini Mental Status Exam (MMSE) and the Clinical Dementia Rating Scale (CDR). Neuropsychiatric symptoms were assessed using two subsets of data from the Neuropsychiatric Inventory (NPI severity and distress), both of which are completed by the patients’ caregivers. Functional decline was assessed using the Functional Activities Questionnaire (FAQ). In both cognitive and functional decline, data were analyzed with linear regression analysis in the population subgroups of All Type Dementia (ATD, which includes MCI for this study) (N=375), Alzheimer’s type dementia (N=187), and Mild Cognitive Impairment (N=74).

In this study, we observed no correlation between CES-D scores at baseline and cognitive or functional decline over one year. However, we observed a significant positive correlation between changes in CES-D scores and NPI-severity scores over one year in patients with ATD (likely the most reliable observation from this study due to larger statistical power) and in the MCI subgroup, but not in the AD subgroup. This relationship may be attributable to a relationship between depression and neuropsychiatric symptoms in general, or to the fact that a person with dementia who exhibits more depressive symptomatology appears more impaired and causes greater distress in their caregivers, despite stability in the objective measures of their cognitive and functional status. This finding may indicate that intervention for depression is needed to alleviated caregiver burden when managing dementia patients.

Increasingly severe depressive symptomatology may exacerbate neuropsychiatric symptomatology but did not correlate with cognitive and functional decline in patients with dementia. More studies are needed to help delineate the relationship between depression and dementia progression.

Increasing concern around perceived neurocognitive decline is increasing the number of referrals to specialists and anxiety for patients. We aimed to explore the likelihood of the “worried well” experiencing neurocognitive decline and developing a neurological diagnosis.

A total of 166 “worried well” patients who attended the Rural and Remote Memory Clinic (RRMC) between 2004 and 2019 were included in this study. Demographic, health, social, and behavioral factors were measured at the initial visit. Mini-Mental State Examination (MMSE), Center for Epidemiologic Studies Depression Scale (CESD), and Functional Activities Questionnaire (FAQ) scores were measured and compared at initial assessment and at 1-year follow-up. MMSE scores over time were assessed with a mean follow-up of 2.95 years (SD 2.87).

No statistically significant difference was seen in MMSE, CESD, or FAQ scores when comparing clinic day to 1-year follow-up, and no consistent pattern of MMSE score over time was seen. Of the 166 patients with subjective cognitive impairment (SCI) on initial assessment, 5 were diagnosed with Alzheimer’s disease (AD) at 8.5, 3.5, 5, 3, and 1.75 years; 2 were diagnosed with MCI at 1 and 2 years; 1 was diagnosed with vascular cognitive impairment at 5 years; and 1 was diagnosed with frontotemporal dementia (FTD) at 0.5 years.

The likelihood of a patient with SCI developing a neurological diagnosis is reassuringly low (9/166), but not irrelevant. This, along with the benefits of early diagnosis and treatment for dementia, leads us to believe that patients with SCI should still be seen in follow-up at least at the 1-year mark.