Apolipoprotein E Allele, Angiotensin-Converting Enzyme and its Inhibitors, in the Development of Alzheimer's Disease

Abstract

Results: The sample was 80% male with an average age of 78.5 years and a mean MMSE of 19.33. The omnibus ANOVA for Digit Span Backward was significant, F (3, 72) 1⁄4 3.7, p 1⁄4 .016. Follow-up post hoc analyses showed that the group that was both depressed and anhedonic had significantly poorer working memory (M 1⁄4 2.4 digits) than the depression only group (M 1⁄4 5.1, p 1⁄4 .002) and the group with neither depression nor anhedonia (M 1⁄4 4.1, p 1⁄4 .020). Of note, the group with anhedonia only (M 1⁄4 3.7) performed better than the group with both depression and anhedonia (p 1⁄4 .09) but significantly worse than the group with depression only (p 1⁄4 .036). There were no differences in overall cognition and attention. Conclusions: Anhedonia had an adverse impact on working memory and depression alone did not. This was observed despite no overall differences on global measures of cognition. The combination of depression and anhedonia had a greater adverse impact on working memory than did anhedonia alone. Anhedonia, via its effect on working memory, may contribute to patients’ difficulty in managing their daily lives. These conclusions are constrained by the small sample size, a limited measure of anhedonia, and the potentially confounding influence of other cognitive symptoms. Further clarification of the nature and influence of anhedonia with and without depression has important diagnostic and treatment implications for AD as well as a number of other psychiatric and neurological disorders.