Occupational differences in a Dutch sample of patients with primary progressive aphasia, behavioral variant frontotemporal dementia, and Alzheimer's dementia

Background: Cognitive reserve is a potential mechanism to cope with brain damage as a result of dementia, which can be defined by indirect proxies, including education level, leisure time activities, and occupational attainment. In this study we explored the association between dementia diagnosis and type of occupation in a retrospective Dutch outpatient memory clinic sample of patients with primary progressive aphasia (PPA), behavioral variant frontotemporal dementia (bvFTD), and Alzheimer's Dementia (AD).

Methods: We included data from 427 patients (bvFTD n = 87, PPA n = 148, AD n = 192) and compared the frequency of occupations (11 categories) between patients and data from the Dutch census using Pearson Χ² tests and we calculated odds ratios (OR) by means of multinomial logistic regression analyses. We also investigated patient group differences in age, sex, education, disease duration, and global cognition.

Results: The frequency of teachers in patients with PPA was significantly higher than the frequency of teachers in patients with bvFTD [OR = 4.79, p = .007] and AD [OR = 2.04, p = .041]. The frequency of teachers in patients with PPA (16%) was also significantly higher than the frequency of teachers in the Dutch census [5.3%; OR = 3.27, p < .001]. The frequency of teachers in both bvFTD and AD groups were not significantly different from the frequency of teachers in the Dutch census (p = .078 and p = .513, respectively).

Conclusions: A potential explanation for our results is the so called "wear and tear" hypothesis, suggesting that teachers have a communication-wise demanding occupation - and therefore are at higher risk to develop PPA. Alternatively, teaching requires continuous communication, hence teachers are more sensitive to subtle changes in their speech and language abilities. Our findings broaden our understanding of the relationship between occupational activity and cognitive reserve in the development of dementia.