Cognitive Training Interventions for Neurocognitive Disorders

With neurocognitive disorders such as dementia and traumatic brain injury (TBI) on the rise, interventions to prevent cognitive decline, are a global priority. Computerised cognitive training (CCT) has proven to be effective in healthy older adults in improving overall cognition, but whether this effect can transfer to declining populations, and be maintained in the long-term is still contentious. To address these questions, this thesis combines three inter-related and original studies. Chapter 2 reviews the current literature on CCT in healthy older adults, and suggests new design factors and methods to improve overall external validity of results. Combining 57 studies and 2,712 control participants, this study uses meta-analytic techniques to illustrate indifferences, firstly between active and passive controls in CCT trials, and secondly between gold standards of randomised controlled trials (RCTs) and their less rigorous counterparts. Furthermore, it suggests a move towards comparator studies is required in this population. Implementing some of these design factors, Chapter 3 investigates the efficacy of two booster training schedules (monthly vs fortnightly) on long-term cognition in the residential care setting. Findings suggest monthly booster sessions may be more beneficial for long-term maintenance of cognitive improvements, however, given the trial was under-powered, results need to be confirmed by larger, well-powered studies. Importantly, the trial illustrates that the implementation of CCT into residential care is logistically plausible. Chapter 4 presents a meta-analysis assessing the efficacy of cognitive training (CT) in individuals with TBI. To investigate its efficacy, fourteen studies encompassing 575 patients were analysed, with findings indicated that CT is modestly effective in improving cognitive and functional outcomes in patients with post-acute TBI. Therefore, CT must play a more significant role in TBI rehabilitation. Whilst showing the potential for CT as a therapeutic intervention in populations exhibiting cognitive decline, these studies also question current methodological factors in the field, call for more appropriate and rigorous designs, and for the implementation of CCT as a primary and secondary prevention strategy for dementia and cognitive decline.