The Relationship Between Personality and Cognitive Performance in Adults with and without Late Life Depression

Abstract

<h3>Introduction</h3> Personality plays an important role in an individual's well-being, impacting mental health and cognition (Sadeq 2018). In the context of aging, this relationship bears increased significance as cognitive capacity declines with advanced age, and personality may serve as a protective or risk factor for further cognitive decline (Sedeq 2018). Researchers have found significant relationships between personality traits and cognitive performance in older adults, although findings are sometimes inconsistent, and few, if any, studies have considered the impact of depression and personality traits in predicting performance on a comprehensive battery of cognitive tests. The aim of this study is to identify the extent to which neuroticism, openness, agreeableness, extraversion, and conscientiousness predict performance across across multiple cognitive domains, taking into consideration education level, sex, and depression status (currently or never depressed). We predict that higher neuroticism in the context of depression will negatively impact cognitive performance across multiple domains, while higher scores in openness and conscientiousness will positively predict cognitive performance. <h3>Methods</h3> Forty adults between the ages of 60-84 (17 depressed) participated in the study. Education (M = 16.2, SD = 2.2) and sex (20 female) were equivocal between the two groups. All participants under went psychiatric evaluation using the SCID-IV and completed an extensive cognitive battery. Personality was assessed using the NEO Personality Inventory-Revised (NEO-PI-R). For data analyses, a series of stepwise linear regression models were were run, with education and sex entered in step 1, depression status entered in step 2, and NEO-PI factor score entered in step 3. Outcome variables included age-corrected measures of IQ, visuospatial skills, word knowledge, memory, executive functioning, complex attention, working memory, language, processing speed, and motor speed and dexterity. <h3>Results</h3> After accounting for education, sex, and MDD status, we found a positive association between agreeableness and performance on the Delis-Kaplan Executive Function System (DKEFS) sorting test. No other personality variables significantly predicted cognitive performance on any measure. <h3>Conclusions</h3> In this sample of older people with and without a history of depression, agreeableness was the sole personality factor that predicted cognitive performance, and was restricted to one measure of executive function. Previous findings on the relationship between agreeableness and cognitive performance have been largely inconsistent, with many researchers reporting finding no significant relationship between agreeableness and cognitive performance. Our findings highlight a need for further investigation on this relationship. Personality did not predict performance on any other cognitive measures in this sample. Many other studies utilized cognitive screening measures over the telephone to assess cognition, which may help to explain the discrepancy in these results from those of other studies. Further, the current sample is much smaller than those of comparison studies, limiting power to detect significant effects. <h3>Funding</h3> VA Research Rehabilitation and Development