Reply to the Letter to the Editor by O'Caoimh et al

We have read with interest the letter of O Caoimh et al entitled, ?Potential for a `Memory Gym? intervention to delay conversion of mild cognitive impairment to dementia,? which was submitted as correspondence to the publication of our Study of Mental and Resistance Training (SMART) trial.1 This letter describes the results of their Memory Gym study. The idea that combinations of interventions in different domains might be optimal for preservation of brain function is supported by a wealth of animal and human literature on enriched environments.2 Epidemiologic studies in human cohorts suggest that a wide variety of physical, psychological, social, educational, cognitive, occupational, nutritional, and spiritual factors may impact rates of cognitive decline, superimposed on genetic, age-related, and pathophysiological profiles. However, the exact combination of strategies that would be most effective clinically, or even whether single interventions are more or less potent than multimodal interventions for either prevention or treatment of cognitive impairment is not at all clear from existing published literature, and further robust, empirical investigation is needed