Cynical hostility (CH), a specific dimension of hostility that consists of a mistrust of others, has been suggested as a high-risk trait for dementia. However, the influence of CH on the incidence of Alzheimer's disease (AD) remains poorly understood. This study investigated whether late-life CH is associated with AD risk and structural neuroimaging markers of AD.

In community-dwelling older adults from the French ESPRIT cohort (n = 1388), incident dementia rate according to CH level was monitored during an 8-year follow-up and analyzed using Cox proportional hazards regression models. Brain magnetic resonance imaging volumes were measured at baseline (n = 508). Using automated segmentation procedures (Freesurfer 6.0), the authors assessed brain grey and white volumes on all magnetic resonance imaging scans. They also measured white matter hyperintensities volumes using semi-automated procedures. Mean volumes according to the level of CH were compared using ANOVA.

Eighty-four participants developed dementia (32 with AD). After controlling for potential confounders, high CH was predictive of AD (HR 2.74; 95% CI 1.10–6.85; p = 0.030) and all dementia types are taken together (HR 2.30; 95% CI 1.10–4.80; p = 0.027). High CH was associated with white matter alterations, particularly smaller anterior corpus callosum volume (p < 0.01) after False Discovery Rate correction, but not with grey matter volumes.

High CH in late life is associated with cerebral white matter alterations, designated as early markers of dementia, and higher AD risk. Identifying lifestyle and biological determinants related to CH could provide clues on AD physiopathology and avenues for prevention strategies.

In 1962 approximately 1.5 million French people living in Algeria were repatriated to France in very poor and often life-threatening conditions. These people constitute a cohort for the study of the long-term impact of gene–environment interaction on depression.

To examine the interaction between a highly stressful life event and subsequent depression, and its modulation by a length polymorphism of the serotonin transporter gene (5–HTTLPR).

A community sample of people aged 65 years and over residing in the Montpellier region of the south of France was randomly recruited from electoral rolls. Genotyping was performed on 248 repatriated persons and 632 controls. Current and lifetime major and minor depressive disorders were assessed according to DSM-IV criteria.

A significant relationship was observed between exposure to repatriation and subsequent depression (P<0.002), but there was no significant effect of gene alone (P = 0.62). After controlling for age, gender, education, disability, recent life events and cognitive function, the gene–environment interaction (repatriation×5-HTTLPR) was globally significant (P<0.002; OR = 3.21, 95% CI 2.48–5.12). Individuals carrying the two short (s) alleles of 5-HTTLPR were observed to be at higher risk (P<0.005; OR = 2.34, 95% CI 1.24–4.32), particularly when repatriation occurred before age 35 years(P<0.002; OR = 2.91, 95% CI 1.44–5.88), but this did not reach significance in those who were older at the time of the event (P = 0.067).

The association between depression and war repatriation was significantly modulated by 5-HTTLPR genotype but this appeared to occur only in people who were younger at the time of exposure.