Positive psychological constructs and cognitive function: A systematic review and meta-analysis.

AIM: To synthesise evidence regarding the association between positive psychological constructs (PPCs) and cognitive function in adults aged 50 +. METHODS: Literature searches: Medline, PsycINFO, and Scopus (inception to February 2022). Studies were included if they reported on the association between at least one PPC and one objective measure of cognitive function in people aged 50 + without cognitive impairment at baseline. Where at least two studies reported on the same PPC and cognitive outcome, estimates were pooled through meta-analysis. FINDINGS: In total, 37 studies were included. There was evidence of cross-sectional associations for 'meaning in life' (verbal fluency: b = 0.09, 95 %CI [0.07, 0.11], p < .001; memory: b = 0.10, 95 %CI [0.08, 0.12], p < .001), 'purpose in life' (verbal fluency: b = 0.07, 95 %CI [0.05, 0.08], p < .001; memory: r = 0.13, 95 %CI [0.08, 0.18], p < .001), and positive affect (cognitive state: r = 0.25, 95 %CI [0.14, 0.36], p < .001; memory: r = 0.05, 95 %CI [0.02, 0.08], p < .001) with various domains of cognitive function. However, no significant results were found for life satisfaction (p = .13) or longitudinal studies investigating positive affect and memory (p = .48). Other PPCs were included in narrative syntheses only. IMPLICATIONS: Purpose and meaning in life may be sensible primary targets for interventions to promote healthy cognitive aging. More longitudinal and causal inference research is needed to better understand this association and its implications for clinical practice.

Are subtypes of affective symptoms differentially associated with change in cognition over time: A latent class analysis.

BACKGROUND: In the absence of disease-modifying treatments, identifying potential psychosocial risk factors for dementia is paramount. Depression and anxiety have been identified as potential risk factors. Studies however have yielded mixed findings, lending possibility to the fact that potential constellations of co-occurring depression and anxiety symptoms may better explain the link between affective symptoms and cognitive decline. METHODS: Data from participants (aged 50 and above) of the PROTECT study was used. Latent Class Analysis (LCA) was conducted on 21,684 participants with baseline anxiety and depression measures. Multiple linear regressions models, using a subset of these participants (N = 6136) who had complete cognition data at baseline and at 2-year follow-up, were conducted to assess for associations between class membership and longitudinal changes in cognition. RESULTS: The LCA identified a 5-class solution: "No Symptoms", "Sleep", "Sleep and Worry", "Sleep and Anhedonia", and "Co-morbid Depression and Anxiety". Class membership was significantly associated with longitudinal change in cognition. Furthermore, this association differed across different cognitive measures. LIMITATIONS: Limitations included significant attrition and a generally healthy sample which may impact generalisability. CONCLUSIONS: Substantial heterogeneity in affective symptoms could explain previous inconsistent findings concerning the association between affective symptoms and cognition. Clinicians should not focus solely on total symptom scores on a single affective domain, but instead on the presence and patterns of symptoms (even if sub-clinical) on measures across multiple affective domains. Identifying particular subgroups that are at greater risk of poor cognitive outcomes may support targeted prevention work.

Positive psychological constructs and association with reduced risk of mild cognitive impairment and dementia in older adults: A systematic review and meta-analysis.

Understanding factors associated with dementia risk is important for informing future interventions aimed at dementia prevention. There is accumulating evidence for the association between depression and risk of dementia, however less is known about the association between positive psychological factors and dementia incidence. This review aims to synthesise evidence regarding the association between positive psychological constructs (PPCs) and later risk of MCI and dementia in adults aged 50 and over. Literature searches were conducted in Medline, PsycINFO, and Scopus until March 2021. Papers reporting on the association between at least one PPC and later risk of MCI or dementia in people aged 50 + without cognitive impairment at baseline were included. Results from the meta-analyses revealed that purpose in life was significantly associated with a reduced risk of dementia (HR = 0.81, 95% CI [0.78, 0.85], p < .001), however results for positive affect were non-significant (HR = 0.94, 95% CI [0.76, 1.15], p = .54). Results for other PPCs are described narratively. Mixed findings for different PPCs highlight the importance of investigating these factors individually. Understanding which factors may play a protective role in their association with risk of mild cognitive impairment and dementia could have important implications for informing dementia prevention interventions.

Widowhood and cognitive decline in adults aged 50 and over: A systematic review and meta-analysis.

While widowhood is known to be associated with poorer physical and mental health outcomes, studies examining the association of widowhood with cognition have yielded mixed results. This review aimed to elucidate the link between widowhood and cognitive decline. A systematic search of Medline, Embase, PsycInfo, CINAHL and Scopus (until December 2020) was conducted to identify studies on the association between widowhood (vs. being married) and cognition in cognitively healthy adults aged 50 +. A cross-sectional meta-analysis (of 10 studies; n = 24,668) found a significant association of widowhood with cognition (g = - 0.36, 95% CI [- 0.47, - 0.25], p = < 0.001). Meta-regressions suggested that study design, cognitive domain measured, sample age, difference in mean age between widowed and married groups, and study continent did not account for observed heterogeneity. A longitudinal meta-analysis (of 3 studies; n = 10,378) found that the "continually widowed" group (from baseline to follow-up) showed significantly steeper declines in cognition compared to the "continually married" group (g = - 0.15, 95%CI [- 0.19, - 0.10], p = < 0.001). Findings indicate that widowhood may be a risk factor for cognitive decline. As there are no effective treatments for cognitive impairment, studying mechanisms by which widowhood might be associated with poorer cognition could inform prevention programs for those who have experienced spousal bereavement.

The presence of alcohol consumption prior to homicide in Singapore.

OBJECTIVE: To determine the prevalence of alcohol use disorders in people charged with homicide in Singapore. We also sought to determine which historical risk factors were associated with the use of alcohol 24 h prior to the homicide and with the presence of a severe mental illness at the material time of the offence. METHODS: We extracted data from administrative records of all people charged with homicide in Singapore between 2007 and 2014. We used regression models to adjust for known confounding variables and explore the relationship between alcohol use and homicide. RESULTS: Of 253 homicide offenders, 141 individuals (56%) meeting criteria for alcohol use disorders at the time of the offence. 121 offenders (48%) consumed alcohol within the 24 h preceding the homicide. Of the 149 that met criteria for a psychiatric diagnosis, 35 had a severe mental illness. CONCLUSION: Alcohol use disorders are by far the most common disorder diagnosed in people charged with homicide in Singapore. Alcohol use is less common in homicide offenders with SMI.

Concurrent and Longitudinal Contribution of Exposure to Bullying in Childhood to Mental Health: The Role of Vulnerability and Resilience.

Importance: Exposure to bullying is associated with poor mental health. However, the degree to which observed associations reflect direct detrimental contributions of exposure to bullying to mental health remains uncertain, as noncausal relationships may arise from genetic and environmental confounding (eg, preexisting vulnerabilities). Determining to what extent exposure to bullying contributes to mental health is an important concern, with implications for primary and secondary interventions. Objective: To characterize the concurrent and longitudinal contribution of exposure to bullying to mental health in childhood and adolescence using a twin differences design to strengthen causal inference. Design, Setting, and Participants: Participants were drawn from the Twins Early Development Study, a population-based cohort recruited from population records of births in England and Wales between January 1, 1994, and December 31, 1996. Data collection took place when the participants were between 11 and 16 years of age from December 1, 2005, to January 31, 2013. Data analysis was conducted from January 1, 2016, to June 20, 2017. Exposures: Participants completed the Multidimensional Peer-Victimization Scale at 11 and 14 years of age. Main Outcomes and Measures: Mental health assessments at 11 and 16 years of age included anxiety, depression, hyperactivity and impulsivity, inattention, conduct problems, and psychotic-like experiences (eg, paranoid thoughts or cognitive disorganization). Results: The 11 108 twins included in the final sample (5894 girls and 5214 boys) were a mean age of 11.3 years at the first assessment and 16.3 years at the last assessment. The most stringent twin differences estimates (monozygotic) were consistent with causal contribution of exposure to bullying at 11 years to concurrent anxiety, depression, hyperactivity and impulsivity, inattention, and conduct problems. Effects decreased over time; that is, substantial concurrent contributions to anxiety (ß = 0.27; 95% CI, 0.22-0.33) persisted for 2 years (ß = 0.12; 95% CI, 0.04-0.20) but not 5 years. Direct contributions to paranoid thoughts and cognitive disorganization persisted for 5 years. Conclusions and Relevance: This study is the largest to date to characterize the contribution of exposure to bullying in childhood to mental health using a twin differences design and multi-informant, multiscale data. Stringent evidence of the direct detrimental contribution of exposure to bullying in childhood to mental health is provided. Findings also suggest that childhood exposure to bullying may partly be viewed as a symptom of preexisting vulnerabilities. Finally, the dissipation of effects over time for many outcomes highlights the potential for resilience in children who were bullied. In addition to programs that aim to reduce exposure to bullying, interventions may benefit from addressing preexisting vulnerabilities and focus on resilience.