The effect of education and occupational complexity on rate of cognitive decline in Alzheimer's patients

Abstract

We explored the effect of education and occupational complexity on the rate of cognitive decline (as measured by the Mini-Mental State Examination) in 171 patients with a confirmed Alzheimer's disease (AD) diagnosis. Complexity was measured as substantive complexity of work and complexity of work with data, people, and things. Average lifetime occupational complexity was calculated based on years at each occupation. Participants were followed for an average of 2.5 years and 3.7 visits. In multivariate mixed-effects models, high education, high substantive complexity, and high complexity of work with data and people predicted faster rates of cognitive decline, controlling for age, gender, native language, dementia severity, and entry into the analyses at initial versus follow-up testing. These results provide support for the concept of cognitive reserve according to which greater reserve may postpone clinical onset of AD but also accelerate cognitive decline after the onset.

No protective effects of education during normal cognitive aging: Results from the 6-year follow-up of the Maastricht Aging Study.

“…decline of cognitive functions once they are diagnosed with AD (Andel, Vigen, Mack, Clark, & Gatz, 2006;Hall et al, 2007;Roe, Xiong, Miller, & Morris, 2007;Scarmeas, Albert, Manly, & Stern, 2006;Stern, Albert, Tang, & Tsai, 1999;Wilson et al, 2004). This faster rate of decline is thought to be caused by a more advanced stage of neuropathology at diagnosis in AD patients with higher education, compared with patients with less education.…”

“…More important, when older individuals without dementia and AD patients are included in the same sample, effects of educational status may be leveled out because the current literature predicts that higher education causes cognitive decline over time to be slower in normal aging (e.g., Stern, 2002) but faster in AD (e.g., Andel et al, 2006). Although none of the individuals in the present study had a diagnosis of dementia at the time of testing, it is possible that individuals in a prodromal stage of a progressive neurodegenerative disease, such as AD, may have distorted the data.…”

Intelligence quotient–adjusted memory impairment is associated with abnormal single photon emission computed tomography perfusion

“…Factors such as education (Stern et al, 1994), occupational status (Stern et al, 1995), life activities (Scarmeas et al, 2003), innate intelligence (Alexander et al, 1997), or a combination of these factors (Andel et al, 2006;Stern et al, 2005) are thought to compose aspects of cognitive reserve that help individuals acquire and use the set of skills necessary to cope with pathology and, therefore, perform normally on cognitive tasks. In this study, we chose to estimate cognitive reserve using a word-reading estimate of premorbid ability, namely the AMNART (Ryan & Paolo, 1992).…”

“…Various proxy measures of cognitive reserve have been explored in several studies, including demographic based regression estimations (Barona et al, 1984), level of education, word reading estimates of premorbid IQ, and more recently, various combinations of education, occupation, and IQ (Andel et al, 2006;Stern et al, 1994Stern et al, , 1995Stern et al, , 2005. In this study, we chose to estimate cognitive reserve using the AMNART, in part because other studies found wordreading estimates of premorbid IQ more sensitive to the neurophysiological effects of AD than other demographic variables (Alexander et al, 1997) or a combination of variables (Bright et al, 2002).…”

El nivel de vocabulario como indicador de reserva cognitiva en la evaluación del deterioro cognitivo ligero

“…De esta forma, una persona con alta reserva cognitiva soportará mayor cantidad de neuropatología disminuyendo el riesgo de manifestar los síntomas clínicos de la enfermedad (Andel, Vigen, Mack, Clark, & Gatz, 2006;De la Barrera, Donolo & Rinaudo, 2010). Desde un enfoque más pasivo de reserva, otros autores proponen el término de "reserva cerebral" que se basa en aspectos neurobiológicos relacionados con el tamaño cerebral, el número de neuronas o la densidad sinápti-ca.…”