Cognitive reserve and its correlates in child and adolescent offspring of patients diagnosed with schizophrenia or bipolar disorder

From Genetics to Psychosocial Functioning: Unraveling the Mediating Roles of Cognitive Reserve, Cognition, and Negative Symptoms in First-Episode Psychosis

BACKGROUND

Studies have shown associations between polygenic risk scores for educational attainment (PRSEA), cognitive reserve (CR), cognition, negative symptoms (NS), and psychosocial functioning in first-episode psychosis (FEP). However, their specific interactions remain unclear. This study aimed to investigate the mediating roles of CR, cognition, and NS in the relationship between PRSEA and psychosocial functioning one year after a FEP. Additionally, we sought to explore the impact of two NS subtypes on this relationship: diminished Expression (EXP-NS) and Motivation and Pleasure (MAP-NS).

METHODS

A total of 138 FEP participants, predominantly male (70%), with a mean age of 24.77 years (SD = 5.29), underwent genetic, clinical, and cognitive assessments two months after study enrollment. Functioning evaluation followed at one-year follow-up. To investigate the mediating role of CR, cognition, and NS in the relationship between PRSEA and functioning, a serial mediation model was employed. Two further mediation models were tested to explore the differential impact of EXP-NS and MAP-NS. Mediation analysis was performed using the PROCESS macro version 4.1 within SPSS version 26.

RESULTS

The serial mediation model revealed a causal chain for PRSEA > CR > cognition > NS > Functioning (β = -3.08, 95%CI [-5.73, -0.43], p = 0.023). When differentiating by type of NS, only EXP-NS were significantly associated in the casual chain (β = -0.17, 95% CI [-0.39, -0.01], p < 0.05).

CONCLUSIONS

CR, cognition and NS -specifically EXP-NS- mediate the association between PRSEA and psychosocial functioning at one-year follow-up in FEP patients. These results highlight the potential for personalized interventions based on genetic predisposition.

Cognitive reserve and cognition in mood disorders: A systematic review and meta-analysis

Cognitive functioning heterogeneity is a well-recognized phenomenon in individuals diagnosed with mood disorders. Cognitive Reserve (CR) has been linked to multiple positive outcomes, including cognitive performance in these patients. This systematic review and meta-analysis aim to provide a comprehensive analysis of the relationship between CR and cognitive functioning in individuals with mood disorders, including bipolar disorder and depressive disorders. Following PRISMA guidelines, a systematic review and meta-analysis was conducted of original research exploring the relationship between CR and cognitive performance in adult individuals with mood disorders. The literature search was conducted on PubMed, Scopus, and Web of Science, from 2002 to September 2023, and the Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of studies. Overall, 17 studies met the inclusion criteria for the systematic review and 11 for the meta-analysis. Both qualitative and quantitative findings suggested a positive relationship between CR measures and cognitive domains. CR emerges as a possible protective factor for cognitive functioning in adult individuals with mood disorders, potentially helping to mitigate the cognitive impairments associated with the disorder. These findings underscore the importance of the fact that promoting and enhancing CR could help in the cognitive prognosis of this population.

Cognitive reserve modulates mental health in adulthood

Cognitive Reserve (CR) reflects acquired knowledge, skills, and abilities throughout life, and it is known for modulating cognitive efficiency in healthy and clinical populations. CR, which was initially proposed to explain individual differences in the clinical presentation of dementia, has subsequently been extended to healthy ageing, showing its role in cognitive efficiency also during middle age. Recently, CR has been linked to affective processes in psychiatric conditions such as schizophrenia, major depressive and anxiety symptoms, and psychological distress, suggesting its potential role in emotional expression and regulation. Whether the role of CR in mental health extends to non-pathological adults, and whether this is only relevant in older age is not yet clear. The aim of this work was therefore to explore the relationship between CR and mental health in healthy adults, with a focus on middle adulthood (40-60). In a sample of 96 participants, we found a positive association between CR and mental health outcomes, such that a higher cognitive reserve index corresponded to fewer mental health reported symptoms. Specifically, a higher CR reflecting professional activities was associated with lower stress levels, especially in middle agers. Taken together, these data therefore suggest that engaging occupations may help maintain a robust mental health, especially by reducing stress symptoms during middle age. These results broaden previous findings suggesting that CR relates to affective components of mental health in middle aged and older adults.

Epigenetic age deacceleration in youth at familial risk for schizophrenia and bipolar disorder

Epigenetic modifications occur sequentially during the lifespan, but their pace can be altered by external stimuli. The onset of schizophrenia and bipolar disorder is critically modulated by stressors that may alter the epigenetic pattern, a putative signature marker of exposure to environmental risk factors. In this study, we estimated the age-related epigenetic modifications to assess the differences between young individuals at familial high risk (FHR) and controls and their association with environmental stressors. The sample included 117 individuals (6-17 years) at FHR (45%) and a control group (55%). Blood and saliva samples were used estimate the epigenetic age with six epigenetic clocks through methylation data. Environmental risk was measured with obstetric complications, socioeconomic statuses and recent stressful life events data. Epigenetic age was correlated with chronological age. FHR individuals showed epigenetic age deacceleration of Horvath and Hannum epigenetic clocks compared to controls. No effect of the environmental risk factors on the epigenetic age acceleration could be detected. Epigenetic age acceleration adjusted by cell counts showed that the FHR group was deaccelerated also with the PedBE epigenetic clock. Epigenetic age asynchronicities were found in the young at high risk, suggesting that offspring of affected parents follow a slower pace of biological aging than the control group. It still remains unclear which environmental stressors orchestrate the changes in the methylation pattern. Further studies are needed to better characterize the molecular impact of environmental stressors before illness onset, which could be critical in the development of tools for personalized psychiatry.