Enhanced memory for negative words is associated with amnestic mild cognitive impairment and in vivo cerebral amyloid‐β burden independently of depression

Abstract

AbstractBackgroundEmotion dysregulation was studied as a potential risk marker for Alzheimer’s disease (AD) by assessing emotional memory in high AD‐risk groups characterized by the presence of mild cognitive impairment (MCI) or remitted major depressive disorder (rMDD) and by evaluating the relationship between emotional memory and in vivo cerebral amyloid‐β deposition.Method435 participants enrolled in the PACt‐MD clinical trial of cognitive remediation plus transcranial direct current stimulation were evaluated at baseline. The sample included 127 older adults with amnestic mild cognitive impairment (aMCI), 51 non‐amnestic MCI (naMCI), 60 rMDD without MCI, 81 rMDD+aMCI, 42 rMDD+naMCI, and 74 cognitively unimpaired older adults (CU). Diagnoses were established during a consensus conference based on psychiatric, medical, and neuropsychological assessment. Emotional memory was assessed by evaluating immediate and short‐term delayed recall of 15 personality adjectives (5 each of positive, negative and neutral words) from the Emotional Verbal Learning Test (Mah et al., 2017, American Journal of Geriatric Psychiatry, 25:1160). A subset (N = 167) completed a Positron Emission Tomography (PET) scan with carbon‐11 Pittsburgh Compound B ([11C] PIB). Valence and diagnostic group effects on recall were assessed using mixed ANOVA. Regression modelling assessed the association between emotional memory bias and amyloid‐β burden.ResultRelative to CU, both aMCI and rMDD+aMCI groups showed enhanced memory for negative words at immediate recall, which persisted after short delay in the aMCI group only (F(1, 339) = 2.66, p = .048; Figure 1). Enhanced memory for negative words at short delay was predictive of in vivo cerebral amyloid‐β deposition (standardized beta = .117, t = 1.84, p = .067), over and above the contributions of age, sex, Apolipoprotein E genotype, depression diagnosis and symptoms, and long delayed verbal recall (F(4,154) = 25.8, p<.001, R2 = .41; Figure 2).ConclusionThe association between enhanced memory for negative personality adjectives and aMCI replicates earlier work in single‐domain aMCI (Mah et al., 2017) and suggests that aMCI is characterized by a negativity bias in memory. These findings, taken together with the relationship between a negativity bias in memory and amyloid‐β burden, suggest that emotion dysregulation, in the form of enhanced memory for negative information, is a potential marker of AD risk.