Dementia is a condition that describes various symptoms of cognitive decline. Older adults who develop dementia struggle with memory, communication, and decision-making skills. Alzheimer’s disease is the most common type of dementia.
Source: CDC Dementia
Neuroticism is a personality trait that is associated with poor stress resilience and often manifests in greater reactivity to life stressors.
Neuroticism is measured with a survey about distress-proneness. Distress-proneness is the major personality trait of a neurotic person. The survey is scored on a scale of 0-36.
Neuroticism, memory, and Alzheimer’s disease
Source: Proneness to psychological distress is associated with risk of Alzheimer’s disease
A well-regarded study called the Religious Orders Study measured aging and Alzheimer’s disease in a sample of older Catholic nuns, priests, and brothers. At the beginning of the study, participants were evaluated based on medical history, a neurological example, cognitive testing, and a brain scan review. They also rated their experience of psychological distress in the Neuroticism Scale.
Over the follow-up period, 140 participants developed Alzheimer’s disease. Researchers used autopsy data from 57 of the 220 participants who died to evaluate clinical impairments to cognition.
Results revealed that participants with high distress proneness had over twice the risk of developing Alzheimer’s disease than those with low distress proneness. There was a particularly strong association between distress proneness and episodic memory, with a 10-fold increase in episodic memory decline in those with high distress proneness. Episodic memory decline is a common symptom of dementia.
Depression and general cognitive functioning did not alter the strength of the association. This means that those factors are not responsible for or can not explain why distress proneness is associated with Alzheimer’s disease.
The results suggest that chronic psychological distress is a risk factor for Alzheimer's disease and that this association probably reflects neurobiological mechanisms other than the pathologic hallmarks of Alzheimer's disease.
Participants in this study were more likely to have received higher education or religious training than the average person. The sample was also 68.4% women and only 8.3% African American. To explore the association further, we looked at a study with a more diverse sample.
Neuroticism in diverse populations
Source: Proneness to psychological distress and risk of Alzheimer disease in a biracial community
A biracial sample of Chicagoans aged 65 or older filled out neuroticism scales and medical history reports. Between 3 and 6 years later, 1,064 of them were examined for Alzheimer’s disease, and 170 were confirmed.
Overall, participants with high distress-proneness were 2.4 times more likely to develop Alzheimer’s disease than participants with low distress-proneness. However, the associations were different among demographic groups. Women had higher scores than men among African Americans, but still less than whites. In addition, the odds of developing Alzheimer’s disease increased by 12% in whites compared to 2% in African Americans.
Although African Americans have been disproportionately exposed to social conditions considered to be particularly stressful, there do not appear to be strong racial differences in negative emotional states or traits. Older African Americans may have developed personal or social resources that help to reduce psychological distress or its deleterious effect on health.