Cognitive interventions in mature and older adults, benefits for psychological well-being and quality of life: a systematic review study

ABSTRACT Few recently published studies investigating the benefits of educational and cognitive interventions on quality of life (QoL), psychological well-being, and depressive symptoms are available. Objective: The aim of this study was to investigate the effects of educational and cognitive interventions on psychological well-being, QoL, and mood in mature and older adults without dementia and/or with mild cognitive impairment (MCI). Methods: The systematic review took place from September to October 2020 and the following databases were used to select the studies: SciELO, LILACS, PubMed, and Medline. The search terms used were idos* AND “treino cognitivo” AND “bem-estar psicológico” AND “qualidade de vida” and their corresponding translations in English and Spanish. Results: Of the 241 articles retrieved, 26 primary studies were included in the review. Of these, 18 showed improvement in QoL, psychological well-being, or cognition. Conclusions: The studies reported beneficial effects of educational and cognitive interventions for QoL, psychological well-being, and depressive symptoms of mature and older adults without dementia or depression.


INTRODUCTION
A ging is a process associated with a host of biological, social, and psychological changes, including those affecting the cognitive domains. One of the main changes seen in cognitive ageing relates to executive functions, which support task planning and execution. Although there is a natural decline in these functions with age, the extent of this impairment is influenced by an individual's extrinsic (environmental) and intrinsic (physical and mental) situation. Physical and cognitive abilities, that is, inherent characteristics, dictate functional capacity, promoting autonomous and independent living. This capacity has a significant impact on the quality of life (QoL) and well-being of older adults. [1][2][3] The decline in functional capacity negatively impacts the QoL, defined as "an individual's perception of his/ her position in life in the context of the culture and value systems in which he/she lives, and about his/her goals, expectations, standards, and concerns." 4 Effects on psychological and social variables can manifest in the form of depressive symptoms, which are closely associated with general, subjective, and psychological well-being since depression undermines an individual's sense of worth. 5 The concept of subjective well-being encompasses emotional factors, positive or negative, and cognitive factors, more associated with personal satisfaction. 6 Psychological well-being is related to six different factors: (1) autonomy: decision-making capacity; (2) purpose in life: having personal goals; (3) personal growth: developing new skills; (4) environmental mastery: management of situations according to context; (5) positive relations: maintaining ties with others; and (6) self-acceptance: having self-knowledge to accept oneself. 5,7 One way of promoting maintenance of psychological well-being is through cognitive intervention.
Cognitive interventions can be divided into three types: (1) Cognitive Stimulation, in which standardized repeated activities are performed without structured learning programs; (2) Cognitive Training, in which standardized activities are established, targeting specific cognitive functions, such as attention, planning, reasoning, among others, while employing strategies to improve intervention outcomes; and (3) Cognitive Rehabilitation, aimed at recovery or compensatory strategies for cognitive impairments. 8,9 In this study, our focus is on cognitive training and cognitive stimulation.
Cognitive training can positively influence psychological well-being and QoL, as found in the study by Irigaray et al. 10 Their results showed that in addition to improvements in cognitive functions such as memory, language apraxias, there was a better perception of QoL and psychological well-being, with regard to the areas of self-acceptance, personal growth, and relationship with the environment. The authors stated that one reason that explains the effect of cognitive training on improving psychological well-being is that cognitive functioning in older adults is also influenced by psychological well-being. These results may indicate a positive association between improvements in cognition and psychological variables.
The study by Seinfeld et al. 11 found that other types of intervention, such as piano practice and stimulation for cognitive domains -motor skills, attention, and executive function -also had beneficial effects in reducing depressive symptoms and improving mood in older adults. Thus, based on the results found, the authors suggested that playing piano at more advanced ages can help increase cognitive reserve, improving or maintaining cognitive function in later life -consistent with the findings of the cited studies. Therefore, although the study did not involve cognitive training per se, the results of the investigations were significant, suggesting that different types of cognitive interventions can improve the aspects of psychological well-being and QoL.
Among the actions used for health promotion, there are educational interventions, whose concept has not been much explored in the literature. What comes closest is the characterization described in the study by Carvalho et al., 12 who proposed that educational interventions are actions that would facilitate the understanding of the subjects involved, promoting the construction of new spaces of knowledge, through educational and dialogical relationships. Given the various intervention strategies presented, the integration of nursing in behavioral science also serves as a guide to explore the motivation or demotivation of the elderly, in addition to self-care in healthy aging, through the use of educational sessions with playful strategies in Social -Poetry workshops. Lima-Silva et al. 13 mentioned that cognitive interventions added to cognitive stimuli can generate benefits for individuals' self-efficacy, which is related to psychological well-being.
The absence of literature reviews on the effects of cognitive and educational interventions on subjective well-being, mood, and QoL of mature and elderly adults limits the possibility of gathering evidence that confirms or contradicts the results found in this study. However, clinical studies of cognitive training and cognitive stimulation have directed their results toward gains in terms of QoL and reduction of depressive symptoms, [14][15][16] while studies of educational intervention have identified improvements in subjective well-being. 17,18 In face of the explicit sociodemographic changes that take place in the course of the human existential trajectory, there is an increase in diseases involving mental health, particularly in the elderly population. 19 However, there is scant literature about cognitive training in cognitively healthy older adults. There is a difficulty in finding studies in the literature that directly focus on the effects of cognitive training on QoL, psychological well-being, and depressive symptoms. This study did not identify other systematic reviews that aimed to ascertain the relationship between cognitive and educational interventions and psychological well-being, QoL, and mood. The only reviews that aimed to investigate the general gains of cognitive training were found.
Most studies found in the literature sample elderly people with preserved cognition, and associate cognitive training with improvements in memory, and also with improvements in social and psychological variables. However, there is a scarcity of comparative studies between the benefits of memory training for elderly people with MCI and for elderly people without any cognitive impairment, which limits the finding of which of the cognitive profiles benefit the most.
Therefore, considering the relevance of studies on cognitive and educational interventions and the gap of systematic reviews on the theme, this systematic literature review sought to address the importance of promoting and reporting the effectiveness of cognitive interventions, such as cognitive training and cognitive stimulation and educational interventions for the elderly, along with the benefits they can bring.
This study aimed to investigate the effects of educational and cognitive interventions on psychological well-being, QoL, and mood in mature and older adults without dementia and/or with MCI.

METHODS
In this study, a systematic review of the literature was conducted according to the guidelines set forth in the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. 20 The search and review of studies, carried out from September to October 2020, was performed on the SciELO, LILACS, PubMed, and Medline databases.
Using the PICo (Population, Interest and Context) framework, 20 the following research question was defined: Can educational and cognitive interventions promote improvement in psychological well-being, mood, and QoL of older adults with MCI and those with depressive symptoms? The population refers to the mature and older adults without dementia and/ or with MCI, the interest refers to the psychological well-being and QoL, and context refers to educational and cognitive intervention, including memory training and cognitive stimulation. After this process, eligible descriptors were selected on the Descriptors in Health Sciences (DeCS) system to serve as keywords for the search. The following search terms were employed: idos* AND "treino cognitivo" AND "bem-estar psicológico" AND "qualidade de vida," their corresponding translations in English: elderly AND "cognitive training" AND "psychological well-being" AND "quality of life" and Spanish: ancianos y "entrenamiento cognitivo" y "bienestar psicológico" and "calidad de vida." The following filters were used to search for articles in the databases: "year 2010 to 2020," "full text," "randomized controlled trial," and language "Portuguese," "English," and "Spanish." Inclusion criteria were applied to articles published between 2010 and 2020. A process of inclusion and exclusion was carried out for the studies retrieved from each database congruent with this review. Inclusion criteria were: randomized clinically controlled trials, cohort studies, and studies involving older adults that were healthy, had MCI or comorbidities, and without neurodegenerative diseases.
In addition, the studies should have been published in Portuguese, English, or Spanish. We included studies analyzing the effects on QoL or psychological well-being.
Exclusion criteria were secondary studies such as systematic reviews, meta-analyses, and studies conducted before 2010 and those that included older adults diagnosed with major neurocognitive disorders. Publications, which were case studies, master's dissertations, doctoral theses, and book chapters, were also excluded. Other studies that failed to satisfy the predefined search criteria were also not included.
First, the titles and abstracts were read. Second, those who met the inclusion criteria, had their objectives, methods, and results filled out in a spreadsheet together with the name of the authors, the year of publication, and with the database website for a double check. The following data were observed: if the participants were 50 years or older; the application and effectiveness of the educational or cognitive intervention and; the use of instruments to assess the variables of subjective well-being and QoL in the pre-and posttest. Up to that stage, the research had been conducted by four reviewers. Finally, after methods, objectives, and results were checked, the selected articles were read completely by two researchers.

RESULTS
The database searches led to the retrieval of 241 articles (6 PubMed, 3 Lilacs, 199 Medline, and 33 SciELO).
After initial filtering for the inclusion of studies published between 2010 and 2020 plus RCTs and exclusion of duplicate studies, 81 articles remained, 4 of which were identified from paper references. Subsequent reading of titles and abstracts of the pre-selected articles led to the exclusion of a further 46, giving a total of 35 publications for a full reading. Finally, 26 studies met all inclusion criteria and were included as a part of this systematic review ( Figure 1).
Of the 26 studies reviewed, most were published in 2018 (19.2%), 15 (57.7%) involved cognitive interventions, and the mean sample size was 212 participants. Concerning participants' cognitive status, 21 (80.8%) studies involved cognitively healthy elderly, 3 (11.5%) investigated older people with and without MCI (11.5%), and 2 (7.7%) assessed groups with and without memory complaints. Published preliminary studies outlining methods only with no results were also assessed (Table 1).
Many studies have found an association between reducing depression symptoms or increasing the QoL or psychological well-being of participants after the intervention. Among the studies, those which offered only educational intervention were the ones that identified an increase in psychosocial well-being. Regarding mood, those which carried out cognitive intervention such as cognitive stimulation, showed more results in reducing depressive symptoms, compared to studies with other types of intervention.

Results
Sample characteristics

Application effects
The study also sought to provide health professionals with a tool for aiding the rehabilitation of institutionalized elderly. to improve PWB and identify transfer effects on an aspect related to PWB, QoL. Transfer effects on a high-level cognitive process, WM, were also investigated.

Lopes and
n=32 Educational Only the trained group reported more significant gains in PWB and WM performance after training.

Cognitively healthy
Psychological well-being. Thomson and Chatterjee (2014) 36 To determine whether therapeutic benefits could be measured objectively using clinical scales.
n=40 Educational (ludic) Positive affect and wellness increased significantly in acute and elderly and residential care though not psychiatric care, whereas negative affect decreased and happiness increased in all settings. Examination of audio recordings revealed enhanced confidence, social interaction, and learning. The program allowed adults access to a museum activity that would not otherwise have engaged with museum objects by age and ill-health.
Cognitively healthy (part of the group had anxiety and depression, but the results were described separately). Outcome assessments were to be conducted at baseline and 18 and 26 weeks after intervention commencement. Participants would report falls and physical activity history for 12 months via monthly calendars. Mixed linear modeling incorporating intervention and CGs at baseline and two follow-ups (18 weeks and 26 weeks after intervention commencement) would be used to assess outcomes.  Other studies combined educational interventions with cognitive interventions, incorporating discussions about memory, aging, and well-being in the cognitive training programs. 11,13,[38][39][40] The study by Irigaray et al., 10 investigating the effects of cognitive training on QoL and psychological well-being, found significant results for both variables. The researchers' first hypothesis to explain this outcome involves the relationship between enhanced cognitive capacity and its benefits for QoL. At the same time, the secondary idea suggests a broadening of participants' social circle.
However, one of the studies analyzed psychological well-being and depressive symptoms and failed to identify significant results. 5 This outcome echoes Silva et al., 28 who also found no improvements in depressive symptoms in training or control groups after a cognitive training intervention in mature and older adults.
In summary, the studies reported positive effects of educational and cognitive interventions for QoL, psychological well-being, and depressive symptoms among mature and older adults without dementia or depression. These results suggest that different intervention strategies can benefit mature and older individuals, warranting further research on the topic.
The results corroborate another systematic review, which investigated the benefits of cognitive training, but without focusing on the three variables evaluated in this study. Gomes et al., 41 in an integrative review on the relationship between cognitive training and functionality in elderly people without cognitive impairment, found that 50% of the studies that were analyzed indicated positive effects of cognitive training on psychological, social, and QoL variables.
Santos and Mendoza, 8 however, in a systematic review of national studies that involved cognitive training, warn of the need for caution when relating cognitive intervention to psychosocial gains. The authors claim that because these are variables measured through self-reporting, responses may be influenced by external factors, which compromises the validity of the information collected. In general, there is a lack of literature reviews on the theme brought up by this study, which prevents the comparison of the results found and, consequently, the application of greater scientific basis.
The main limitations of this review were a dearth of methodological processes in studies involving cognitive and educational interventions among cognitively healthy mature and older adults or those with MCI, particularly regarding the application of assessment instruments pre-and posttest. In addition, there was a lack of cognitive training interventions concomitantly DISCUSSION This systematic review study aimed to analyze educational and cognitive interventions and determine their effects on associated subjective variables, such as QoL, psychological well-being, and depressive symptoms in cognitively healthy mature and older adults, subjects with MCI and no depression. The approach entailed analysis of several instruments and aspects associated with definitions of QoL and psychological well-being. 7,21 Cognitive type interventions employ a range of different approaches: olfactory training, 22 cognitive training using electronic devices, such as computers or tablets, 13,23-26 training using musical instruments, 10 training through manual interventions, 27 training using categorization strategies, 28 and multifactorial training, 14,15,25,[29][30][31][32] which proved the most predominant approach (7/15 cognitive intervention studies).
The majority of the studies reviewed, which involved cognitive nature activities, showed significant results for at least one of the variables assessed (QoL, psychological well-being, depressive symptoms, or mood). The study by Birte-Antina, 22 whose sample received olfactory training, found improvements for cognition, psychological well-being, QoL, and depressive symptoms. By contrast, three studies failed to achieve significant results for QoL or psychological well-being post-intervention. 15,16,26 Buitenweg et al. 26 concluded that a possible explanation for nonsignificant effects in the sample investigated might lie in the fact that the elderly participants had high cognitive performance and low depression symptoms preintervention.
Educational type interventions tend to be used for promoting health, given that the individual is empowered to practice self-care and thus has greater adherence to professional practices. 12 Studies with an educational approach in the present literature review focused on the following areas: healthy lifestyle, 33 personal growth, 17,34 falls prevention, 35 and play-oriented activities involving museum object handling 36 or dance. 18 The study by Cantarella et al., 17 in which a group of women participated in classes and discussions aimed at favoring personal growth, found significant results for participants' psychological well-being following the intervention. The results were consistent with the findings of the studies by Cachioni et al. 7 and Ordonez et al., 37 assessing subjective and psychological well-being of elderly participants of an open Universidade da Terceira Idade, which identified positive effects of education on general satisfaction with life, where students engaged in the interventions for longer had more significant results. investigating effects on QoL, psychological well-being, depressive symptoms, and mood among older adults. Another limitation was the absence of a calculation that could measure the effect size of the results found. In addition, there was a lack of prior registration of the review protocol in a database.
Despite the limitations, the results found sugg-est that there is a relationship between educational and cognitive interventions and psychological and QoL variables. Therefore, these practices can be applied by professionals who seek improvements beyond cognition and learning. This possibility allows the adoption of complementary strategies to provide psychosocial gains for mature and elderly adults.
It is suggested, for future research, that there is greater deepening in the comparison of the gains from educational interventions and the gains resulting from cognitive interventions.