Visual memory dysfunction as a neurocognitive endophenotype in bipolar disorder patients and their unaffected relatives. Evidence from a 5-year follow-up Valencia study

Neurocognitive and psychosocial functioning profiles in bipolar disorder and comorbid attention deficit hyperactivity disorder: A systematic review and meta-analysis

Bipolar disorder (BD) and attention deficit hyperactivity disorder (ADHD) are chronic psychiatric conditions with significant impacts on neurocognitive and psychosocial functioning. Co-occurrence of BD and ADHD (BD-ADHD) presents unique clinical challenges and could exacerbate cognitive and functional impairments. This systematic review and meta-analysis aimed to provide an updated synthesis of the differences in neurocognitive and psychosocial functioning between patients with BD-ADHD, BD, ADHD, and healthy controls (HC). A comprehensive systematic search identified 5639 records, with 34 studies meeting the inclusion criteria for a systematic review and 31 for the meta-analysis. There were no significant differences in cognitive performance across none of the evaluated cognitive domains between BD-ADHD and BD patients. BD-ADHD patients exhibited significantly lower visual memory (SMD=-0.29, 95 % CI=-0.53,-0.04; p = 0.022) compared to ADHD patients. Compared to HC, BD-ADHD patients showed poorer performance in processing speed (SMD=-0.54, 95 % CI= -0.86,-0.22; p < 0.001), sustained attention (SMD=-0.40, 95 % CI=-0.62, -0.19; p < 0.001), visual memory (SMD=-0.47, 95 % CI=-0.69,-0.26; p < 0.001), working memory (SMD=-0.79, 95 % CI=-1.13,-0.44; p < 0.001), cognitive flexibility and higher-order executive functions (SMD=-0.52, 95 % CI=-0.84,-0.20; p = 0.001), and verbal memory (SMD=-0.95, 95 % CI=-1.43,-0.47; p < 0.001). Psychosocial functioning was significantly worse in BD-ADHD patients compared to BD (SMD=-0.46; p < 0.001), ADHD (SMD=-1.00; p < 0.001), and HC (SMD=-3.54; p < 0.001). Our results suggest that the co-occurrence of BD and ADHD is associated with significant neurocognitive and psychosocial impairments. These findings underscore the need for targeted interventions to address the unique challenges of this comorbid condition, informing clinical practice and guiding future research.

Clinical outcomes and anti-inflammatory mechanisms predict maximum heart rate improvement after physical activity training in individuals with psychiatric disorders and comorbid obesity

INTRODUCTION

This study aimed to evaluate the predictive validity and discriminatory ability of clinical outcomes, inflammatory activity, oxidative and vascular damage, and metabolic mechanisms for detecting significant improve maximum heart rate after physical activity training in individuals with psychiatric disorders and obesity comorbid using a longitudinal design and transdiagnostic perspective.

METHODS

Patients with major depressive disorder, bipolar disorder and, schizophrenia and with comorbid obesity (n = 29) were assigned to a 12-week structured physical exercise program. Peripheral blood biomarkers of inflammation, oxidative stress, vascular mechanisms, and metabolic activity, as well as neurocognitive and functional performance were assessed twice, before and after intervention. Maximum heart rate was considered a marker of effectiveness of physical activity. Mixed one-way analysis of variance and linear regression analyses were performed.

RESULTS

Individuals with psychiatric disorders and comorbid obesity exhibited an improvement in cognition, mood symptoms and body mass index, increase anti-inflammatory activity together with enhancement of the oxidative and cardiovascular mechanisms after physical activity training (p<0.05 to 0.0001; d = 0.47 to 1.63). A better clinical outcomes along with regulation of inflammatory, oxidative, and cardiovascular mechanisms were critical for predicting significant maximum heart rate variation over time (χ2 = 32.2 to 39.0, p < 0.0001).

CONCLUSIONS

The regulation of the anti-inflammatory mechanisms may be essential for maintained of healthy physical activity across psychiatric disorders and obesity. Likewise, inflammatory activity, oxidative stress, vascular and cardio-metabolic mechanisms may be a useful to identify individuals at greater risk of multi-comorbidity.

Decision-making using the Iowa gambling test in unaffected first-degree relatives of obsessive-compulsive disorder: Comparison with healthy controls and patients with obsessive-compulsive disorder

Decision-making has been suggested as an endophenotype candidate for obsessive-compulsive disorder (OCD). However, few studies have examined whether decision-making under ambiguity is an endophenotype of OCD. This study aimed to investigate decision-making under ambiguity, as assessed by the Iowa Gambling Task (IGT), in patients with OCD and unaffected first-degree relatives (UFDR). Forty-seven non-medicated, non-co-morbid patients with OCD, 30 UFDR, and 47 healthy controls (HC) were compared in terms of decision-making using the IGT. The correlation between obsessive-compulsive symptoms and IGT performance was also investigated. Patients with OCD and UFDR performed worse than HC on the IGT. No correlation was found between obsessive-compulsive symptoms and IGT performance. A deficit in decision-making under ambiguity may be a trait and an endophenotype candidate for OCD.

Exercise as a promoter of neurocognitive improvement in people with psychiatric disorders and comorbid obesity: A randomized controlled trial

INTRODUCTION

The psychiatric disorders and obesity comorbidity is related to neurocognitive impairment and inflammation. Exercise is crucial to improve and maintain healthy lifestyles. This randomized controlled trial tested the efficacy of aerobic exercise as promoter of neurocognitive improvement across psychiatric disorders with comorbid obesity (OB).

METHODS

Patients with major depressive disorder, bipolar disorder and, schizophrenia and with comorbid OB (n = 29) received brief healthy lifestyle counseling and were randomized into two groups: guided physical activity group (GPAG) (n = 10) which included 12 weeks of guided-exercise of moderate intensity and frequency, and incentive of autonomous physical activity proposals by the specialist. Standard physical activity group (SPAG) (n = 19) continue with their usual daily physical activity, without guidance or incentives, over 12 weeks. Peripheral blood biomarkers of inflammation, oxidative stress, vascular mechanisms, and metabolic activity, as well as neurocognitive and functional performance were assessed twice, before and after intervention. Mixed one-way analysis of variance and linear regression analyses were performed.

RESULTS

Individuals in GPAG showed better neurocognitive and functional performance than individuals in SPAG after physical activity training (p < 0.05; η²p = 0.14 to 0.15). A significant improvement in cognition before and after the physical activity training in the GPAG group was found (p < 0.0001; η²p = 0.29). In all cases, the effect size was from moderate to large. Inflammatory activity (interleukin [IL-6]), oxidative (mitochondrial reactive oxygen species [mROS] and mitochondrial membrane potential [ΔΨm]) and inter cellular adhesion molecule 1 [ICAM1], leukocyte-endothelium adhesion [LEPMN], and p-selectin [PSEL]) levels, and cardio-metabolic (low-density lipoprotein [LDL], systolic blood pressure [SBP], and insulin) processes were significant predicting neurocognitive improve of individuals with psychiatric disorders and comorbid OB.

CONCLUSIONS

Physical activity programs may have positive impact on neurocognitive and functional performance in individuals with psychiatric disorders and OB. Exercise influences inflammatory, oxidative, vascular, and cardio-metabolic pathways, and modulate cognition. These findings may have a potential translational utility for early intervention in these disorders.

Verbal fluency in schizophrenia and bipolar disorder - A longitudinal, family study

Verbal fluency (VF) has been proposed as a putative neurocognitive endophenotype in schizophrenia (SZ) and bipolar disorder (BD). However, this hypothesis has not been examined using a longitudinal family approach. We conducted a five-group, comparative study. The sample comprised 323 adult participants, including 81 BD patients, 47 unaffected relatives of BD BD-Rel), 76 SZ patients, 40 unaffected relatives of SZ (SZ-Rel), and 79 genetically unrelated healthy controls (HC). All subjects were assessed twice with semantic VF (sem-VF) and phonological VF (ph-VF) tests over a 2-year follow-up period. ANCOVAs controlling for age and years of education were used to compare performance across groups. Patients with SZ and BD and their unaffected relatives showed sem-VF and ph-VF deficits at baseline, which persisted over time (all, p < 0.05). Moreover, BD-Rel showed an intermediate performance between SZ and HC. A repeated-measures ANOVA revealed no significant differences in the between-group trajectories comparison (p > 0.05). Our findings support that VF may represent a neurocognitive endophenotype for SZ and BD. Further longitudinal, family studies are warranted to confirm this preliminary evidence.

Development of an eye-tracking system based on a deep learning model to assess executive function in patients with mental illnesses

Patients with mental illnesses, particularly psychosis and obsessive‒compulsive disorder (OCD), frequently exhibit deficits in executive function and visuospatial memory. Traditional assessments, such as the Rey‒Osterrieth Complex Figure Test (RCFT), performed in clinical settings require time and effort. This study aimed to develop a deep learning model using the RCFT and based on eye tracking to detect impaired executive function during visuospatial memory encoding in patients with mental illnesses. In 96 patients with first-episode psychosis, 49 with clinical high risk for psychosis, 104 with OCD, and 159 healthy controls, eye movements were recorded during a 3-min RCFT figure memorization task, and organization and immediate recall scores were obtained. These scores, along with the fixation points indicating eye-focused locations in the figure, were used to train a Long Short-Term Memory + Attention model for detecting impaired executive function and visuospatial memory. The model distinguished between normal and impaired executive function, with an F1 score of 83.5%, and identified visuospatial memory deficits, with an F1 score of 80.7%, regardless of psychiatric diagnosis. These findings suggest that this eye tracking-based deep learning model can directly and rapidly identify impaired executive function during visuospatial memory encoding, with potential applications in various psychiatric and neurological disorders.

Inflammation and lipid metabolism as potential biomarkers of memory impairment across type 2 diabetes mellitus and severe mental disorders

INTRODUCTION

Neurocognitive impairment is a transdiagnostic feature across several psychiatric and cardiometabolic conditions. The relationship between inflammatory and lipid metabolism biomarkers and memory performance is not fully understood. This study aimed to identify peripheral biomarkers suitable to signal memory decline from a transdiagnostic and longitudinal perspective.

METHODS

Peripheral blood biomarkers of inflammation, oxidative stress and lipid metabolism were assessed twice over a 1-year period in 165 individuals, including 30 with schizophrenia (SZ), 42 with bipolar disorder (BD), 35 with major depressive disorder (MDD), 30 with type 2 diabetes mellitus (T2DM), and 28 healthy controls (HCs). Participants were stratified by memory performance quartiles, taking as a reference their global memory score (GMS) at baseline, into categories of high memory (H; n = 40), medium to high memory (MH; n = 43), medium to low memory (ML; n = 38) and low memory (L; n = 44). Exploratory and confirmatory factorial analysis, mixed one-way analysis of covariance and discriminatory analyses were performed.

RESULTS

L group was significantly associated with higher levels of tumor necrosis factor-alpha (TNF-α) and lower levels of apolipoprotein A1 (Apo-A1) compared to those from the MH and H groups (p < 0.05; η2p = 0.06-0.09), with small to moderate effect sizes. Moreover, the combination of interleukin-6 (IL-6), TNF-α, c-reactive protein (CRP), Apo-A1 and Apo-B compounded the transdiagnostic model that best discriminated between groups with different degrees of memory impairment (χ2 = 11.9-49.3, p < 0.05-0.0001).

CONCLUSIONS

Inflammation and lipid metabolism seem to be associated with memory across T2DM and severe mental illnesses (SMI). A panel of biomarkers may be a useful approach to identify individuals at greater risk of neurocognitive impairment. These findings may have a potential translational utility for early intervention and advance precision medicine in these disorders.

The trajectory of emotional and non-emotional cognitive function in newly diagnosed patients with bipolar disorder and their unaffected relatives: A 16-month follow-up study

Cognitive impairments are evident in remitted patients with bipolar disorder (BD) and their unaffected relatives (UR) compared to healthy controls (HC). However, the temporal course of cognition, and whether cognition is marked by neuroprogressive changes, remain unclear. In a large prospective study of newly diagnosed patients with BD, we assessed patients with BD (n = 266), UR (n = 105) and HC (n = 190) using an extensive cognitive battery of non-emotional and emotional cognition at baseline and 16-months follow-up. Cognitive change across groups was examined with linear mixed-model analyses. Results showed no evidence of trajectory differences between patients with BD, UR, and HC in neurocognition and emotional cognition (ps≥.10). Patients with BD showed stable impairments in global neurocognitive functioning over time, as well as within the domains of 'working memory and executive function' and 'attention and psychomotor speed', compared to HC. Patients who relapsed during the follow-up time were less successful at down-regulating emotions in positive social scenarios compared to HC. Unaffected relatives also displayed stable deficits in 'working memory and executive function' over time, with performance at intermediate levels between BD probands and HC. Finally, poorer neurocognition and positive emotion regulation were associated with more subsyndromal symptoms and functional impairments. In conclusion, we found no evidence of a neuroprogressive origin of cognitive impairments in the newly diagnosed BD or in their UR. Patients' and UR's impairments in working memory and executive function may reflect a stable cognitive trait-marker of familial risk. Difficulties with positive emotion regulation may be associated with illness progression in BD.

MICEmi: A method to identify cognitive endophenotypes of mental illnesses

BACKGROUND

Characterizing neurocognitive endophenotypes of mental illnesses (MIs) could be useful for identifying at-risk individuals, increasing early diagnosis, improving disease subtyping, and proposing therapeutic strategies to reduce the negative effects of the symptoms, in addition to serving as a scientific basis to unravel the physiopathology of the disease. However, a standardized algorithm to determine cognitive endophenotypes has not yet been developed. The main objective of this study was to present a method for the identification of endophenotypes in MI research.

METHODS

For this purpose, a 14-expert working group used a scoping review methodology and designed a method that includes a scoring template with five criteria and indicators, a strategy for their verification, and a decision tree.

CONCLUSIONS

This work is ongoing since it is necessary to obtain external validation of the applicability of the method in future research.

Specific metabolic syndrome components predict cognition and social functioning in people with type 2 diabetes mellitus and severe mental disorders

OBJECTIVE

Obesity and metabolic diseases such as metabolic syndrome (MetS) are more prevalent in people with type 2 diabetes mellitus (T2DM), major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ). MetS components might be associated with neurocognitive and functional impairments in these individuals. The predictive and discriminatory validity of MetS and its components regarding those outcomes were assessed from prospective and transdiagnostic perspectives.

METHODS

Metabolic syndrome components and neurocognitive and social functioning were assessed in 165 subjects, including 30 with SZ, 42 with BD, 35 with MDD, 30 with T2DM, and 28 healthy controls (HCs). A posteriori, individuals were classified into two groups. The MetS group consisted of those who met at least three of the following criteria: abdominal obesity (AO), elevated triglycerides (TG), reduced high-density lipoprotein cholesterol (HDL), elevated blood pressure (BP), and elevated fasting glucose (FPG); the remaining participants comprised the No-MetS group. Mixed one-way analysis of covariance and linear and binary logistic regression analyses were performed.

RESULTS

Cognitive impairment was significantly greater in the MetS group (n = 82) than in the No-MetS group (n = 83), with small effect sizes (p < 0.05; η²p = 0.02 - 0.03). In both groups, the most robust associations between MetS components and neurocognitive and social functioning were observed with TG and FPG (p < 0.05). There was also evidence for a significant relationship between cognition and BP in the MetS group (p < 0.05). The combination of TG, FPG, elevated systolic BP and HDL best classified individuals with greater cognitive impairment (p < 0.001), and TG was the most accurate (p < 0.0001).

CONCLUSIONS

Specific MetS components are significantly associated with cognitive impairment across somatic and psychiatric disorders. Our findings provide further evidence on the summative effect of MetS components to predict cognition and social functioning and allow the identification of individuals with worse outcomes. Transdiagnostic, lifestyle-based therapeutic interventions targeted at that group hold the potential to improve health outcomes.

Immune-Inflammatory Biomarkers Predict Cognition and Social Functioning in Patients With Type 2 Diabetes Mellitus, Major Depressive Disorder, Bipolar Disorder, and Schizophrenia: A 1-Year Follow-Up Study

Background

Systemic, low-grade immune-inflammatory activity, together with social and neurocognitive performance deficits are a transdiagnostic trait of people suffering from type 2 diabetes mellitus (T2DM) and severe mental illnesses (SMIs), such as schizophrenia (SZ), major depressive disorder (MDD), and bipolar disorder (BD). We aimed to determine if immune-inflammatory mediators were significantly altered in people with SMIs or T2DM compared with healthy controls (HC) and whether these biomarkers could help predict their cognition and social functioning 1 year after assessment.

Methods

We performed a prospective, 1-year follow-up cohort study with 165 participants at baseline (TB), including 30 with SZ, 42 with BD, 35 with MDD, 30 with T2DM, and 28 HC; and 125 at 1-year follow-up (TY), and determined executive domain (ED), global social functioning score (GSFS), and peripheral blood immune-inflammatory and oxidative stress biomarkers.

Results

Participants with SMIs and T2DM showed increased peripheral levels of inflammatory markers, such as interleukin-10 (p < 0.01; η2 p = 0.07) and tumor necrosis factor-α (p < 0.05; η2 p = 0.08); and oxidative stress biomarkers, such as reactive oxygen species (ROS) (p < 0.05; η2 p = 0.07) and mitochondrial ROS (p < 0.01; η2 p = 0.08). The different combinations of the exposed biomarkers anticipated 46-57.3% of the total ED and 23.8-35.7% of GSFS for the participants with SMIs.

Limitations

Participants' treatment, as usual, was continued without no specific interventions; thus, it was difficult to anticipate substantial changes related to the psychopharmacological pattern.

Conclusion

People with SMIs show significantly increased levels of peripheral immune-inflammatory biomarkers, which may contribute to the neurocognitive and social deficits observed in SMIs, T2DM, and other diseases with systemic immune-inflammatory activation of chronic development. These parameters could help identify the subset of patients who could benefit from immune-inflammatory modulator strategies to ameliorate their functional outcomes.

Transdiagnostic neurocognitive deficits in patients with type 2 diabetes mellitus, major depressive disorder, bipolar disorder, and schizophrenia: A 1-year follow-up study

BACKGROUND

Neurocognition impairments are critical factors in patients with major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ), and also in those with somatic diseases such as type 2 diabetes mellitus (T2DM). Intriguingly, these severe mental illnesses are associated with an increased co-occurrence of diabetes (direct comorbidity). This study sought to investigate the neurocognition and social functioning across T2DM, MDD, BD, and SZ using a transdiagnostic and longitudinal approach.

METHODS

A total of 165 participants, including 30 with SZ, 42 with BD, 35 with MDD, 30 with T2DM, and 28 healthy controls (HC), were assessed twice at a 1-year interval using a comprehensive, integrated test battery on neuropsychological and social functioning.

RESULTS

Common neurocognitive impairments in somatic and psychiatric disorders were identified, including deficits in short-term memory and cognitive reserve (p < 0.01, η²p=0.08-0.31). Social functioning impairments were observed in almost all the disorders (p < 0.0001; η²p=0.29-0.49). Transdiagnostic deficits remained stable across the 1-year follow-up (p < 0.001; η²p=0.13-0.43) and could accurately differentiate individuals with somatic and psychiatric disorders (χ² = 48.0, p < 0.0001).

LIMITATIONS

The initial sample size was small, and high experimental mortality was observed after follow-up for one year.

CONCLUSIONS

This longitudinal study provides evidence of some possible overlap in neurocognition deficits across somatic and psychiatric diagnostic categories, such as T2DM, MDD, BD, and SZ, which have high comorbidity. This overlap may be a result of shared genetic and environmental etiological factors. The findings open promising avenues for research on transdiagnostic phenotypes of neurocognition in these disorders, in addition to their biological bases.

The long-term course of cognition in bipolar disorder: a systematic review and meta-analysis of patient-control differences in test-score changes

Neuropsychological impairment represents a key aspect of bipolar disorder (BD) that is evident even in early-course patients and is a strong predictor of functional outcomes among those affected. Previous meta-analyses of longitudinal studies suggest that BD-related cognitive deficits may not progress along the course of the disorder. However, short test-retest periods were used in most primary studies and comparisons with healthy controls were limited. The aim of this review was to synthesize the findings of research reports comparing long-term neurocognitive trajectories between BD patients and healthy individuals. PubMed, PsycINFO, and Scopus databases were searched from inception through July 2021. Publications were considered for inclusion if they reported cognitive test scores of BD patients and healthy controls at two different time points, with a minimum test-retest interval of 5 years. Fifteen studies compared the long-term course of cognition in BD patients with that of healthy controls. Ten of these were included in the quantitative analysis and involved 540 BD patients and 644 healthy individuals (mean follow-up period: 8.9 years). Patient-control effect sizes (standardized mean differences) were calculated for test-score changes in 24 neuropsychological variables and combined by means of meta-analytic procedures. No significant differences were found between patients and controls regarding long-term cognitive outcomes. These findings are consistent with previous shorter-term longitudinal meta-analyses and do not provide evidence for progressive cognitive deterioration in most bipolar individuals. Future studies should address the longitudinal course of cognition in different subgroups of BD patients and its prognostic and therapeutic value.

Is processing speed a valid neurocognitive endophenotype in bipolar disorder? Evidence from a longitudinal, family study

BACKGROUND

Substantial evidence supports the existence of neurocognitive endophenotypes in bipolar disorder (BD), but very few longitudinal studies have included unaffected relatives. In a 5-year, follow-up, family study, we have recently suggested that deficits in manual motor speed and visual memory could be endophenotype candidates for BD. We aimed to explore whether this also applies to processing speed.

METHODS

A sample of 348 individuals, including 163 BD patients, 65 unaffected first-degree relatives (BD-Rel) and 120 genetically unrelated healthy controls (HC), was assessed with the Digit Symbol Substitution Test (DSST) on two occasions over a 2-year period (T1, T2). DSST values were controlled for age, years of education, occupational status, and subsyndromic mood symptoms. Differences between groups were evaluated with ANCOVAs.

RESULTS

At T1 BD performed significantly worse than HC (p < 0.001; Cohen's d = 1.38) and BD-Rel (p < 0.001; Cohen's d = 0.82). BD-Rel showed an intermediate performance with significant differences with HC (p < 0.01; Cohen's d = 0.50). Similarly, at T2 BD performed significantly worse than HC (p < 0.001; Cohen's d = 1.44) and BD-Rel (p < 0.01; Cohen's d = 0.51). BD-Rel performance was intermediate and significantly lower than that of HC (p < 0.01; Cohen's d = 0.97). A Repeated Measures ANOVA revealed no significant between-group differences in performance over time (p > 0.05).

CONCLUSIONS

The results of this longitudinal, family study suggest that impaired processing speed may represent a suitable cognitive endophenotype for BD. Further research on the field is required to confirm these preliminary findings.

Pediatric bipolar disorder: Executive, linguistic, mnemonic, and cognitive efficiency mapping

Neuropsychological assessment can enrich our understanding of Pediatric Bipolar Disorder (PB). This study aimed to: (1) analyze the occurrence of neuropsychological frequency of deficits and difficulties in children with PB; (2) verify whether there is a performance difference between PB type I (PB-I) and PB type II (PB-II)/unspecified, and between PB with and without ADHD; and (3) verify the cognitive efficiency differences within the PB group and control groups, and among clinical subgroups. Participants in the study were 16 children diagnosed with PB and 40 children with typical development (6-12 years old). The results indicated a high frequency of deficits/difficulties in verbal fluency, cognitive efficiency in performing basic abilities, inhibitory control, cognitive flexibility, and working memory, with emphasis on verbal and executive losses. There were indications that type PB-I and comorbidity with ADHD negatively impact a child's neuropsychological development. The clinical group showed more cognitive efficiency losses compared with the control group, and greater losses were observed in PB-I and in PB with ADHD. The role of neuropsychological evaluation in multidomain and nonlinear statistical analysis is critical to gaining an understanding of the clinical and cognitive heterogeneity of PB.