Friday, February 7, 2014

Learn More, Care More?

Cognitive reserve has been linked to apathy for the first time, according to a new article in Archives of Clinical Neuropsychology (Shapiro, Mahoney, Peyser, Zingman, & Verghase, 2014). Cognitive reserve refers to the brain’s ability to demonstrate resilience to brain damage that results from problems such as Alzheimer’s Disease. As an example, Individuals with a high amount of cognitive reserve may experience few memory problems despite Alzheimer’s pathology existing in the brain. Factors that may help build cognitive reserve include education, higher intelligence, and regular engagement in both mental and physical activities throughout the lifespan (For those interested in cognitive reserve in general, check out the fascinating video below on the Nun study).

The protective effects of cognitive reserve have generally been examined in relation to neurocognitive domains such as memory. Shapiro and colleagues wanted to see if cognitive reserve would also be protective against the effects of apathy. More specifically, they investigated individuals diagnosed with Human Immunodeficiency Virus (HIV), a disorder which is often associated with neurocognitive and neuropsychiatric symptoms including apathy. Cognitive reserve was measured through a composite score consisting of participants’ highest level of educational attainment and scores on the Wechsler Test of Adult Reading (WTAR), while apathy was measured using a brief self-report measure. Researchers accounted for possible confounding variables such as age, gender, disease duration, markers of disease severity, and scores on the Beck Depression Inventory.

31% of participants demonstrated clinically significant apathy based on the self-report measure. The authors stated that cognitive reserve significantly predicted apathy overall (p = .02), but the method section indicated that an alpha level of .01 was used for all analyses. Therefore, this main effect should not have been significant. In any case, there was a significant interaction between cognitive reserve and a marker of the stage of advancement of the disease (nadir CD4 counts). Specifically, individuals with greater cognitive reserve experienced less apathy than those with lower amounts of it, but only for those participants who were in a later stage of HIV infection (p < .001). For those participants in an earlier stage of infection, cognitive reserve did not significantly predict apathy. The authors hypothesize that this protective effect against apathy is a result of “more efficient neural processing and more effective compensation.”

This paper is interesting in that it was able to find a link between cognitive reserve and apathy possibly for the first time; however, this link was found only in individuals with more advanced HIV. It’s not clear why this was the case. The study also has some limitations which were noted by the researchers, including the lack of a healthy control group and an inability to determine causality. Another possible problem that is not addressed is the fact that the overall mean word reading test scores fell in the borderline range. Therefore, these results may not generalize to the general population in which the mean should fall in the average range.

Shapiro, M. E., Mahoney, J. R., Peyser, D., Zingman, B. S., & Verghese, J. (2014). Cognitive reserve protects against apathy in individuals with Human Immunodeficiency Virus. Archives of Clinical Neuropsychology, 29, 110-120.

No comments:

Post a Comment