The brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism affects memory performance in older adults

Objective: Memory impairment is an important contributor to the reduction in quality of life experienced by older adults, and genetic risk factors seem to contribute to variance in age-related cognitive decline. Brain-derived neurotrophic factor (BDNF) is an important nerve growth factor linked with development and neural plasticity. The Val66Met polymorphism in the BDNF gene has been associated with impaired episodic memory in adults, but whether this functional variant plays a role in cognitive aging remains unclear. The purpose of this study was to investigate the effects of the BDNF Val66Met polymorphism on memory performance in a sample of elderly adults. Methods: Eighty-seven subjects aged > 55 years were recruited using a community-based convenience sampling strategy in Porto Alegre, Brazil. The logical memory subset of the Wechsler Memory Scale-Revised was used to assess immediate verbal recall (IVR), delayed verbal recall (DVR), and memory retention rate. Results: BDNF Met allele carriers had lower DVR scores (p = 0.004) and a decline in memory retention (p = 0.017) when compared to Val/Val homozygotes. However, we found no significant differences in IVR between the two groups (p = 0.088). Conclusion: These results support the hypothesis of the BDNF Val66Met polymorphism as a risk factor associated with cognitive impairment, corroborating previous findings in young and older adults.

Crack-cocaine dependence and aging: effects on working memory

Objective: To compare the working memory (WM) performance of young adult crack-cocaine dependent users, healthy older adults, and a control group of healthy young adults. Methods: A total of 77 female participants took part in this study: 26 young adult crack-cocaine dependent users (CRK), 19 healthy older adults (HO), and 32 healthy younger adults (HC). All participants completed the N-back verbal task. Results: A multivariate analysis of covariance was performed. The model included education, income, and medication use as covariates. A group effect (F6,140 = 7.192, p < 0.001) was found. Post-hoc analyses showed that the performance of the CRK and HO groups was reduced compared to the HC group in two N-back conditions. No differences between the HO and CRK groups on WM performance were found. Conclusions: CRK participants perform similar to HO participants on a WM task, despite the well-known effects of age on WM and the young age of CRK. These data point to a possible parallel between cognitive declines associated with crack use and developmental aging.

Déficits na memória de trabalho em idosos com depressão maior: uma revisão sistemática / Impairment of working memory during a depression of the elderly: a systematic review

A depressão em idosos é associada com prejuízos cognitivos, entretanto a extensão destes à Memória de Trabalho (MT) ainda não é consensual. Portanto, o objetivo deste estudo é revisar sistematicamente as associações encontradas entre MT e depressão em idosos. Para tanto conduzimos uma revisão sistemática dos artigos publicados entre 2000 e 2011 nas principais bases de dados internacionais. Posteriormente a aplicação dos critérios de exclusão, 17 artigos foram revisados integralmente. Os resultados apresentam evidências da associação entre depressão geriátrica e prejuízos da MT, que em alguns trabalhos ainda foram mantidos mesmo após a remissão da sintomatologia de humor.

Geriatric depression is related with cognitive impairments, but how this is connected to specific Working Memory deficits is still unknown. Hence, the aim of this study is to systematically review the literature about the associations between Working Memory impairments and major depression in the elderly. Thus we performed a systematic review, considering published articles in major international databases between 2000 and 2011. After exclusion criteria, 17 articles were fully reviewed. There is evidence that there is indeed an association between depression in elderly and Working Memory impairments. In addition, some articles found that such deficits are sustained even after mood symptoms remission.

Tarefa N-back auditiva: desempenho entre diferentes grupos etários / Auditory N-back task: different age groups performance

Um dos instrumentos mais utilizados internacionalmente para avaliação da Memória de Trabalho (MT) é a Tarefa N-back Auditiva. Recursos para avaliação desse sistema são escassos no Brasil. O presente estudo objetiva observar o desempenho da Tarefa N-back Auditiva em indivíduos de diferentes faixas etárias: 27 crianças, 22 pré-adolescentes, 26 adultos e 27 idosos. Os resultados mostram que o grupo etário influencia no desempenho da Tarefa N-back Auditiva. A acurácia foi aumentando na transição da infância para a pré-adolescência e seguiu em crescimento até a adultez. Observou-se um declínio no desempenho de idosos. Os dados da Tarefa N-back Auditiva corrobora a trajetória desenvolvimental, sugerindo que essa tarefa possa ser utilizada no contexto experimental. Pesquisas de normatização contribuirão para melhor compreensão dessa tarefa.

One of the most internationally used instruments for evaluation of Working Memory (WM) is the Auditory N-Back Task. In Brazil, resources to evaluate this system are scarce. The aim of this study is to investigate the performance of different age subjects in auditory n-back tasks. We divided the 102 subjects in four groups: 27 children, 22 adolescents, 26 young adults and 27 older adults. The results demonstrate an age-related difference in the n-back task performance. The accuracy increased in the transition from childhood to adolescence and kept growing from adolescence to adulthood. We also found a decrease in the performance of aged subjects. The Auditory N-Back Task results are in agreement with WM development trajectory, and so, it demonstrates to be an adjusted instrument to evaluate this system in experimental setting.