Neuroticism is a stable and heritable personality trait that is strongly linked to depression. Yet, little is known about its association with late life depression, as well as how neuroticism eventuates into depression. This study used data from the Wisconsin Longitudinal Study (WLS; N=4,877) to examine the direct and indirect effects of neuroticism on late life depression at three points in the life course – ages 53, 64, and 71 – via stressful life events (i.e., independent and dependent) and social supports measured across adulthood and into later life. Neuroticism was rigorously assayed using multiple methods, including self-report measures and a polygenic score informed by a meta-analytic genome-wide association study. Results indicated that the association between self-reported neuroticism and late life depression was partially mediated via the effects of dependent stressful life events experienced after the age of 53 and by age 64 (T2) social support. There were no specific indirect effects of self-reported neuroticism on depression through the effects of age 53 social support (T1), age 71 social support (T3), adult dependent stressful life events (experienced between age 19 and 52), and adult and late life independent stressful life events. These associations were replicated when we examined the direct and indirect effects of the polygenic score for neuroticism on late life depression, providing key evidence that our findings are robust. Results are consistent with previous findings that individuals with high neuroticism may be vulnerable to late life depression through psychosocial risk factors that are, in part, attributable to their own personality.
Stressful life events and cognitive decline in late life: moderation by education and age. The Cache County Study
