Semantic and episodic memory performances of patients with Alzheimer’s disease and minor neurocognitive disorder

Abstract

AbstractBackgroundModified Dead‐Alive Test (M‐DAT), which was developed and validated by Ozel‐Kizil et. al. (2018) evaluates semantic and episodic memory together. The original form was developed by Kapur et al. (1989), however it was not adequately studied.MethodM‐DAT consists of 45 names of celebrities who had died in remote past (15), died in the last five years (15) and who are still alive (15) and participants are asked whether they are alive or dead. Correct number of items concerning celebrities who died in remote past gives the semantic memory performance, while half of the the sum of correct number of items concerning celebrities who are still alive and had died in the last five years is accepted as episodic memory performance. Semantic and episodic memory performances of patients with DSM‐5 major neurocognitive disorder due to Alzheimer’s Disease‐MND‐AD (n=69), patients with DSM‐5 minor neurocognitive disorder‐MiND (n=27) who were admitted to geriatric psychiatry clinic and volunteered healthy controls‐HC (n=29) were compared. The groups were compared either by one‐way ANOVA or Kruskal‐Wallis tests and Bonferroni or Mann Whitney U tests was used for post‐hoc analysis.ResultMND‐AD group was older and less educated. Also MND‐AD group had lower MMSE scores while MiND and HCs had similar scores. MND‐AD had lower semantic and episodic scores than MiND and HC, also the scores of MiND group were lower than HCs. Both M‐DAT semantic and episodic scores were positively correlated with education in the whole sample (R=.53, p<0.001; R=.43, p<0.001). Although semantic memory performances were higher than episodic memory performances in all groups, two scores were positively correlated (R=.71, p<0.001).ConclusionThe results of the study suggested a semantic memory impairment as well as episodic memory deficit in patients with major and minor neurocognitive disorder. Although previous studies have conflicting results, semantic memory deficit early in Alzheimer’s disease and in mild cognitive impairment was also reported (3). M‐DAT is an alternative for the assessment of semantic memory that is usually evaluated by verbal fluency tests. Evaluating episodic and semantic memory together is an important advantage however M‐DAT is affected by education and the items require updating.