Depression, Cognition, Apolipoprotein E Genotype: Latent Class Approach to Identifying Subtype

Abstract

Objectives-Possessing the ε4 allele of apolipoprotein E (APOE-ε4) genotype is associated with cognitive impairment in non-demented older adults. We hypothesized that we might find a subtype of depression related to impaired cognitive performance associated with the APOE-ε4 allele. Design-A survey conducted between 2001-2003 with APOE genotyping.Setting-Primary care offices in the Baltimore, Maryland area.Participants-The study sample consisted of 305 adults aged 65 or older with complete information on APOE genotyping and covariates.Measurements-We used the latent class model to classify respondents according to symptom criteria of the American Psychiatric Association's Diagnostic and Statistical Manual as assessed in the Composite International Diagnostic Interview and the following four measures of cognitive function: the Mini-Mental State Exam, Hopkins Verbal Learning Test, Controlled Oral Word Association Test, and the Brief Test of Attention. We examined the relationship between class membership and APOE genotype.Results-The latent class model yielded three classes: a non-depressed class, a class with depressive symptoms and average cognitive functioning, and a class with depressive symptoms (particularly thoughts of death and suicide) and impaired cognitive functioning. Possessing at least one APOE-ε4 allele was not predictive of class membership.Conclusion-A subgroup of elderly patients with depressive symptoms, cognitive impairment, and a high likelihood of experiencing thoughts of death or suicide may exist that may not be related to APOE-ε4. Subgroups of older patients with depressive symptoms may be important to identify because of the association with thoughts of death or suicide and cognitive impairment (249 words). Keywordsaged; depressive symptoms; cognition; genetic testing; apolipoprotein E; primary careCorresponding Author and Reprints: Hillary R. Bogner, MD, MSCE, Assistant Professor, Department of Family Medicine and Community Health, University of Pennsylvania, 3400 Spruce Street, 2 Gates Building, Philadelphia, PA 19104, Phone: 215-615-0851, Fax: 215-662-3591, hillary.bogner@uphs.upenn.edu. NIH Public Access Author ManuscriptAm J Geriatr Psychiatry. Author manuscript; available in PMC 2010 April 1. Objectives A significant percentage of older depressed adults also have cognitive impairment [1]. Studies based on diagnostic criteria for major and minor depression may miss important associations between depression symptoms and cognitive impairment among older adults. Subtypes of depression in which symptoms are present intermittently or in which sadness and anhedonia are denied may be as important as major depression in older adults because of the association with cognitive impairment. For example, Blazer and colleagues, employing grade-ofmembership analysis to analyze the Durham-Piedmont ECA data, found a symptom profile tending to occur in older persons in which cognitive impairment was prominent and accompanied by sleep and appetite disturbance, hopelessness, and thoughts of de...

Heterogeneity in Depression Symptoms and Health Status Among Older Adults

“…The evidence supported the idea that the presentation of depression symptoms among older adults is heterogeneous. Results showing that the majority of participants reported low levels of depression symptoms are similar to the findings obtained with similar methods in samples of adults and older adults (Bogner, Richie, de Vries, & Morales, 2009;Chen, Eaton, Gallo, & Nestadt, 2000) indicating that poor mental health is not the norm among older individuals (Alexopoulos et al, 2002). The prevalence of individuals with high levels of depression symptoms in the current sample is consistent with epidemiological data from older adults (Lyness, Caine, King, Cox, & Yoediono, 1999;Steffens et al, 2000).…”

The Brain-Derived Neurotrophic Factor Val66Met Polymorphism, Hippocampal Volume, and Cognitive Function in Geriatric Depression

“…Other genes associated with differences in cognition such as apolipoprotein E ( APOE ) (48, 49) and Catechol-o-methyl transferase ( COMT ) (50) might also alter results, though these interactions were not examined in this study. Potential gene-gene interactions need to be considered, as one gene’s effect may be modulated by other genes.…”

Depression and Cognition in the Elderly

“…Moreover, APOE ε4 carriers with depression were 7.1 times more likely to progress to AD compared to non-APOE ε4 carriers with depression, who were only 1.6 times more likely to develop AD (Irie et al 2008). Bogner et al (2009) found that there was no relationship between APOE status and depression (most notably, thoughts of death or suicide) with cognitive impairment. A more extensive study showed that plasma Aβ42 levels independently predicted late-onset depression and AD development in subjects who had never been depressed or did not have current cognitive impairment, suggesting a common biological etiology for these two conditions (Blasko et al 2010).…”