Cognitive intervention programs for individuals with mild cognitive impairment: systematic review of the literature

This systematic literature review addressed the efficacy of 15 cognitive intervention programs that have been tested in individuals presenting with mild cognitive impairment of the amnestic type (MCI-A) possibly at risk to progress toward dementia. MEDLINE, PsycINFO, and Current Content databases were searched using the following key terms: cognitive training, cognitive stimulation, cognitive rehabilitation, neuropsychological intervention, memory training, memory stimulation, and Mild Cognitive Impairment. The data showed statistically significant improvements at the end of training on 44% of objective measures of memory, when compared with 12% of objective measures of cognition other than memory. Statistically significant improvements after treatment were obtained on 49% of subjective measures of memory, quality of life, or mood. Samples sizes ranged from 1 to 193 patients with MCI-A but were usually < or =30. Five studies were randomized controlled trials, eight were quasiexperimental designs, and two were single-case investigations. Some programs focused only on memory, whereas other programs used multifaceted approaches targeting two or more cognitive functions. Eight were offered in groups, and seven took place on an individual basis. Recommendations to improve cognitive interventions in MCI-A are proposed, such as using large samples and a robust experimental design, as well as the implementation of a standardized cognitive training manual. Well standardized and validated direct and indirect measures of efficacy and noncognitive outcomes are also a crucial issue. A consensus meeting among all the experts working on cognitive training in this population should occur to provide guidelines to improve this treatment option.