The Impact of Depressive Symptoms on Cognitive Decline and Risk for Dementia

As of 2011, the life expectancy for Latinos in the U.S. was 81.6 years, which is higher compared to non-Hispanic Blacks (75.3 years), non-Hispanic Whites (79 years), and Hispanic Black populations (74.9 years; Arias, 2011; Arias, 2015). Latinos have higher age specific prevalence of dementia, which is higher than African Americans and non-Hispanic Whites (Gurland et al.,1999). Latinos experience Alzheimers disease symptoms 6.8 years earlier, with the average onset of 67.6 years which is younger than non-Hispanic Whites (73.1 years; Clark et al., 2005). Furthermore, older Latinos tend to experience depression at a rate of 13% and 35% with the prevalence reported among Mexicans in the United States being between 4% and 28% (Hernandez, Prohaska, Wang, & Sarkisian, 2013; Kwag, Jang, & Chiriboga, 2012). The data from this study are longitudinal and drawn from the Sacramento Area Latino Study on Aging (SALSA; Haan et al., 2003). Structural equation modeling (SEM) was used to examine whether the association between depressive symptoms and cognitive decline was mediated by risk for dementia. A correlational analyses was used to examine the association between depression, risk for dementia, cognitive functioning, years of education, and income level. The mediation models indicated that those with moderate to severe levels of depression are at an increased risk for dementia compared to those with subclinical levels of depression. Our findings also revealed that participants with higher depressive scores had fewer years of education and lower income. Those who died over the course of the study reported higher depression scores at time 2. Participants born in Mexico also reported higher depressive scores. Participants who had a higher education level, income and cognitive functioning had a lower risk for dementia. Participants born in the U.S. had greater levels of cognitive functioning, than those who were born in Mexico