Cognitive Interventions Targeting Subjective Cognitive Complaints

Abstract

Subjective cognitive complaints (SCCs) are being increasingly recognized as a preclinical phase of dementia. Thus, SCCs may represent a "promising" stage for planning and implementing preventive interventions aimed at reducing the incidence of cognitive disorders. The aim of the present study is to present and discuss the available evidence coming from clinical trials adopting cognitive interventions in individuals with SCCs. A systematic review of literature was conducted to evaluate the available trials testing nonpharmacological cognitive interventions for the prevention of dementia in subjects with SCCs. Six studies were included in the present study. Overall, most interventions showed to objectively improve cognitive performance in subjects with SCCs. A relevant heterogeneity was found concerning their characteristics and feasibility. Conversely, there is a current lack of evidence in the literature about the efficacy of nonpharmacological cognitive interventions for preventing dementia or cognitive impairment.

Efficacies of Cognitive Interventions in the Elderly with Subjective Cognitive Decline: A Prospective, Three-Arm, Controlled Trial

“…This approach was based on previous studies showing better transfer effects in multidomain CI. 3 Although we did not find statistically significant differences in the pri-mary outcome variables, our results are consistent with previous studies targeting SCD and the normal elderly, in that the CI improved verbal memory function and executive function. 8,9,11,35,36 Moreover, social interactions and emotional activities during the CI program enhanced the QoL and mood status, which is consistent with previous evidence.…”

“…1,2 Despite its heterogeneity and uncertainty, SCD is attracting increasing research interest because it is a common condition in the elderly population and most disease-modifying interventions fail in the prodromal or later stage of Alzheimer's disease (AD). 3 SCD has recently been considered the first symptomatic stage of AD, based on previous biomarker studies. 1,2,4 In later periods of preclinical AD, rapid cognitive decline and compensations for the decline lead affected individuals to perceive cognitive worsening, even though objective im-JCN pairments are not yet evident.…”

“…1 This situation means that SCD might be the most-appropriate target for the secondary prevention of the AD continuum. 3 A cognitive intervention (CI) is thought to be a promising nonpharmacological therapy for improving cognition and delaying clinical progression, possibly via brain plasticity and increased cognitive reserve. 5 Because synaptic structures in the brain are modifiable even in old age, consistent and vigorous cognitive activities such as participating in CI programs should enhance cognition via optimization for more-efficient and flexible brain connectivity.…”

“…5,6 However, evidence is currently lacking for supporting the application of CIs to SCD. 3,7 Previous trials of SCD have produced conflicting results [8][9][10][11][12][13] due to ambiguous definitions of SCD, differences in study designs and methodological qualities, focusing only on memory function, small samples, and short study durations. 3,7 In this study we hypothesized that nonpharmacological CIs would show cognitive benefits in subjects with SCD.…”

Non-Pharmacologic Interventions for Older Adults with Subjective Cognitive Decline: Systematic Review, Meta-Analysis, and Preliminary Recommendations

“…After screening for duplication and elimination of ineligible studies (e.g., younger adults with chemotherapy-related cognitive impairment), 16 were deemed appropriate for initial inclusion. These articles were supplemented by manual retrieval of articles from five prior systematic reviews and meta-analyses (Canevelli et al, 2013;Floyd & Scogin, 1997;Gross et al, 2012;Metternich et al, 2010;Wilson, 2005), as well as published manuscripts known to any NON-PHARMACOLOGIC INTERVENTIONS IN SCD 11 of the authors that did not emerge in the search protocol. The automated and manual search protocols resulted in a combined total of 38 articles to be considered for inclusion.…”