Manual motor speed dysfunction as a neurocognitive endophenotype in euthymic bipolar disorder patients and their healthy relatives. Evidence from a 5-year follow-up study

Long-term course of cognitive functioning in bipolar disorder: A ten-year follow-up study

INTRODUCTION

Cognitive impairments are common in bipolar disorder (BD), but the long-term course remains understudied. Longitudinal data on cognitive functioning from the start of the first treatment could help clarify pathophysiological processes that shape the illness outcome. We here aim to investigate the 10-year cognitive course in BD compared to healthy controls (HC) and the effects of clinical symptoms on cognitive trajectories.

METHODS

Fifty-six BD participants recruited within their first year of treatment and 108 HC completed clinical and cognitive assessments at baseline and 10-year follow-up. We derived eight cognitive domain scores and a cognitive composite score, which were further investigated using linear mixed model analyses. Correlation analyses were used to assess associations between the composite score and depressive, manic and psychotic symptoms.

RESULTS

BD participants performed poorer than HCs in all domains except mental speed and verbal fluency. Verbal learning and memory, verbal fluency and the composite score improved over time in both BD participants and HC, while short-term memory, mental speed, psychomotor speed and working memory were stable. We found no significant correlations between cognition and symptom level at either time point in BD participants.

CONCLUSIONS

We found evidence of long-term cognitive stability or improvement in BD participants from first treatment to 10-year follow-up. Though the BD group was impaired in all domains except mental speed and verbal fluency, the change in cognitive functioning was parallel to that of HCs. These findings are not consistent with the notion of neuroprogression in BD.

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.

Can neurological soft signs and neurocognitive deficits serve as a combined endophenotype for Han Chinese with bipolar disorder?

BACKGROUND

Bipolar disorder's (BD) potential endophenotypes include neurological soft signs (NSS) and neurocognitive disorders (ND). Few research, meanwhile, has coupled NSS and ND as combined endophenotypes of BD.

OBJECT

This study intends to investigate NSS and ND and compare their differences in euthymic patients with bipolar disorder (EBP), their unaffected first-degree relatives (FDR), and healthy controls (HC). Additionally, search for potential endophenotypic subprojects of NSS and ND and construct and verify a composite endophenotypic.

METHODS

The subjects were all Han Chinese and consisted of 86 EBP, 81 FDR, and 81HC. Cambridge Neurological Inventory and MATRICSTM Consensus Cognitive Battery tested NSS and ND independently.

RESULTS

All three groups displayed a trapezoidal distribution of NSS levels and cognitive abnormalities, with EBP having the most severe NSS levels and cognitive deficits, followed by FDR and HC. Among them, motor coordination in NSS and Information processing speed (IPS), Verbal learning (VL), and Working memory (WM) in neurocognitive function are consistent with the traits of the endophenotype of BD. The accuracy in differentiating EBP and HC or FDRs and HC was higher when these items were combined as predictor factors than in differentiating EBP and FDR.

CONCLUSION

These results provide more evidence that motor coordination, IPS, VL, and WM may be internal characteristics of bipolar disease. When these characteristics are combined into a complex endophenotype, it may be possible to distinguish BD patients and high-risk groups from normal populations.

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.

Differential trajectory of cognitive functions in neurocognitive subgroups of newly diagnosed patients with bipolar disorder and their unaffected first-degree relatives - A longitudinal study

BACKGROUND

Cognitive impairments exist in a large proportion of remitted patients with bipolar disorder (BD). However, no study has investigated the cognitive trajectories across neurocognitive subgroups of patients or their unaffected first-degree relatives (UR).

METHODS

Newly diagnosed BD patients, UR and healthy controls (HC) underwent comprehensive cognitive testing at baseline and at 16-months follow-up. Hierarchical cluster analysis was conducted to identify homogeneous subgroups of patients based on their neurocognitive profile at baseline. Cognitive change across subgroups of patients and UR was assessed with linear mixed-model analyses.

RESULTS

Data from baseline and follow-up were collected from 152 patients, 53 UR and 135 HC. Patients were clustered into three discrete neurocognitive subgroups: 'cognitively normal' (43%), 'mild-moderately impaired' (33%) and 'globally impaired' (24%). While 'mild-moderately impaired' patients and HC showed normative cognitive improvement over time in global cognition (p < .001), 'globally impaired' patients showed greater improvement than all groups (p < .001), whereas 'cognitively normal' patients showed a lack of normative improvement (p = .17). UR of impaired patients showed a lack of normative improvement in executive functions (p = .01). 'Globally impaired' patients also presented with stable impairments in facial expression recognition and emotion regulation.

LIMITATIONS

Follow-up data was available for 62% of participants, possibly reflecting a selection bias.

CONCLUSIONS

The greater cognitive improvement in 'globally impaired' patients partly speaks against neuroprogression. However, the lack of normative improvement in 'cognitively normal' patients could indicate negative effects of illness. Further follow-up assessments are warranted to clarify whether lack of normative improvement in executive function in UR represents an illness risk-marker.

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; η²p = 0.07) and tumor necrosis factor-α (p < 0.05; η²p = 0.08); and oxidative stress biomarkers, such as reactive oxygen species (ROS) (p < 0.05; η²p = 0.07) and mitochondrial ROS (p < 0.01; η²p = 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.

The effect of concomitant benzodiazepine use on neurocognition in stable, long-term patients with bipolar disorder

OBJECTIVE

Neurocognitive dysfunction is a common feature of bipolar disorder even in euthymia, and psychopharmacological treatment could have an effect on cognition. Long-term prescription of benzodiazepines in bipolar disorder is a common practice, and their effect on neurocognition has not been well studied in this population. The aim of this study was to evaluate the impact of concomitant benzodiazepine long-term use on neurocognitive function in stable euthymic bipolar disorder patients.

METHODS

Seventy-three euthymic bipolar disorder outpatients and 40 healthy individuals were assessed using a neurocognitive battery. Patients were classified in two groups according to the presence of benzodiazepines in their treatment: the benzodiazepine group (n = 34) and the non- benzodiazepine group (n = 39). Neurocognitive performance was compared between the groups using a multivariate analysis of covariance, considering age, number of depressive episodes, adjuvant antipsychotic drugs, Young Mania Rating Scale score and Hamilton Depression Rating Scale score as covariates.

RESULTS

Both bipolar disorder groups (benzodiazepine and non-benzodiazepine) showed an impairment in memory domains (Immediate Visual Memory [p = 0.013], Working Memory [p < 0.001], and Letter-Number Sequence [p < 0.001] from the Wechsler Memory Scale-Revised-III) and slower processing speed functions (Stroop Colour [p < 0.001]) relative to the control group. Nevertheless, the benzodiazepine group showed a greater impairment in executive functions (Conceptual Level Responses [p = 0.024] from the Wisconsin Card Sorting Test and Frontal Assessment Battery [p = 0.042]).

CONCLUSION

Although memory and processing speed impairments were found in bipolar disorder, regardless of their benzodiazepine treatment, benzodiazepine users presented additional neurocognitive impairments in terms of executive functioning. These findings support restricted prescription of benzodiazepines in individuals with bipolar disorder.

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.

Manipulations of the Response-Stimulus Intervals as a Factor Inducing Controlled Amount of Reaction Time Intra-Individual Variability

Aggrandized fluctuations in the series of reaction times (RTs) are a very sensitive marker of neurocognitive disorders present in neuropsychiatric populations, pathological ageing and in patients with acquired brain injury. Even though it was documented that processing inconsistency founds a background of higher-order cognitive functions disturbances, there is a vast heterogeneity regarding types of task used to compute RT-related variability, which impedes determining the relationship between elementary and more complex cognitive processes. Considering the above, our goal was to develop a relatively new assessment method based on a simple reaction time paradigm, conducive to eliciting a controlled range of intra-individual variability. It was hypothesized that performance variability might be induced by manipulation of response-stimulus interval’s length and regularity. In order to verify this hypothesis, a group of 107 healthy students was tested using a series of digitalized tasks and their results were analyzed using parametric and ex-Gaussian statistics of RTs distributional markers. In general, these analyses proved that intra-individual variability might be evoked by a given type of response-stimulus interval manipulation even when it is applied to the simple reaction time task. Collected outcomes were discussed with reference to neuroscientific concepts of attentional resources and functional neural networks.

Grip Strength, Neurocognition, and Social Functioning in People WithType-2 Diabetes Mellitus, Major Depressive Disorder, Bipolar Disorder, and Schizophrenia

BACKGROUND

Frailty is a common syndrome among older adults and patients with several comorbidities. Grip strength (GS) is a representative parameter of frailty because it is a valid indicator of current and long-term physical conditions in the general population and patients with severe mental illnesses (SMIs). Physical and cognitive capacities of people with SMIs are usually impaired; however, their relationship with frailty or social functioning have not been studied to date. The current study aimed to determine if GS is a valid predictor of changes in cognitive performance and social functioning in patients with type-2 diabetes mellitus and SMIs.

METHODS

Assessments of social functioning, cognitive performance, and GS (measured with an electronic dynamometer) were conducted in 30 outpatients with type 2 diabetes mellitus, 35 with major depressive disorder, 42 with bipolar disorder, 30 with schizophrenia, and 28 healthy controls, twice during 1-year, follow-up period. Descriptive analyses were conducted using a one-way analysis of variance for continuous variables and the chi-squared test for categorical variables. Differences between groups for the motor, cognitive, and social variables at T1 and T2 were assessed using a one-way analysis of covariance, with sex and age as co-variates (p < 0.01). To test the predictive capacity of GS at baseline to explain the variance in cognitive performance and social functioning at T2, a linear regression analysis was performed (p < 0.05).

RESULTS

Predictive relationships were found among GS when implicated with clinical, cognitive, and social variables. These relationships explained changes in cognitive performance after one year of follow-up; the variability percentage was 67.7%, in patients with type-2 diabetes mellitus and 89.1% in patients with schizophrenia. Baseline GS along with other variables, also predicted changes in social functioning in major depressive disorder, bipolar disorder, and schizophrenia, with variability percentages of 67.3, 36, and 59%, respectively.

CONCLUSION

GS combined with other variables significantly predicted changes in cognitive performance and social functioning in people with SMIs or type-2 diabetes mellitus. Interventions aimed to improve the overall physical conditions of patients who have poor GS could be a therapeutic option that confers positive effects on cognitive performance and social functioning.

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Objective:

To review the current evidence for efficacy of cannabidiol in the treatment of mood disorders.

Methods:

We systematically searched PubMed, Embase, Web of Science, PsychInfo, Scielo, ClinicalTrials.gov, and The Cochrane Central Register of Controlled Trials for studies published up to July 31, 2019. The inclusion criteria were clinical trials, observational studies, or case reports evaluating the effect of pure cannabidiol or cannabidiol mixed with other cannabinoids on mood symptoms related to either mood disorders or other health conditions. The review was reported in accordance with guidelines from Preferred Reporting Items for Systematic reviews and Meta-Analyses protocol.

Results:

Of the 924 records initially yielded by the search, 16 were included in the final sample. Among them, six were clinical studies that used cannabidiol to treat other health conditions but assessed mood symptoms as an additional outcome. Similarly, four tested cannabidiol blended with Δ-9-tetrahydrocannabinol in the treatment of general health conditions and assessed affective symptoms as secondary outcomes. Two were case reports testing cannabidiol. Four studies were observational studies that evaluated the cannabidiol use and its clinical correlates. However, there were no clinical trials investigating the efficacy of cannabidiol, specifically in mood disorders or assessing affective symptoms as the primary outcome. Although some articles point in the direction of benefits of cannabidiol to treat depressive symptoms, the methodology varied in several aspects and the level of evidence is not enough to support its indication as a treatment for mood disorders.

Conclusions:

There is a lack of evidence to recommend cannabidiol as a treatment for mood disorders. However, considering the preclinical and clinical evidence related to other diseases, cannabidiol might have a role as a treatment for mood disorders. Therefore, there is an urgent need for well-designed clinical trials investigating the efficacy of cannabidiol in mood disorders.

Exploring the Relationship of Transdiagnostic Mood and Psychosis Symptom Domains with Motor Dysfunction

BACKGROUND

A number of motor abnormalities have been reported in psychotic disorders, including dyskinesia and psychomotor slowing. There is also evidence for many of the same motor abnormalities in biological first-degree relatives and accruing evidence for motor abnormalities in bipolar disorder. In addition to motor dysfunction, there are also shared symptom domains amongst these populations.

OBJECTIVES

We explored the associations of (1) current and lifetime psychosis and mood symptom domains and (2) domains of psychosis proneness with various domains of motor function in a transdiagnostic sample (n = 149).

METHOD

Individuals with schizophrenia, schizoaffective disorder, or bipolar disorder, biological first-degree relatives of individuals with a psychotic disorder, and controls completed measures of psychomotor speed and movement fluidity, and neural activity related to motor preparation (stimulus-locked lateralized readiness potential, S-LRP) and execution (response-locked LRP) was assessed using EEG. All participants completed the Brief Psychiatric Rating Scale; patients were additionally assessed for lifetime psychosis and mood episode symptoms, and relatives and controls completed the Chapman psychosis proneness scales.

RESULTS

Multiple regression revealed levels of current negative symptoms and mania were significantly positively associated with psychomotor slowing even after accounting for current antipsychotic medication dosage and duration of illness. S-LRP onset latency was significantly positively associated with magical ideation.

CONCLUSION

Domains of motor function are associated with various mood and psychosis symptom domains in a transdiagnostic sample, which may provide insight into brain abnormalities relevant to the expression of symptoms across disorders.

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

BACKGROUND

Scarce research has focused on Visual Memory (VM) deficits as a possible neurocognitive endophenotype of bipolar disorder (BD). The main aim of this longitudinal, family study with healthy controls was to explore whether VM dysfunction represents a neurocognitive endophenotype of BD.

METHODS

Assessment of VM by Rey-Osterrieth Complex Figure Test (ROCF) was carried out on a sample of 317 subjects, including 140 patients with BD, 60 unaffected first-degree relatives (BD-Rel), and 117 genetically-unrelated healthy controls (HC), on three occasions over a 5-year period (T1, T2, and T3). BD-Rel group scores were analyzed only at T1 and T2.

RESULTS

Performance of BD patients was significantly worse than the HC group (p < 0.01). Performance of BD-Rel was also significantly different from HC scores at T1 (p < 0.01) and T2 (p = 0.05), and showed an intermediate profile between the BD and HC groups. Only among BD patients, there were significant differences according to sex, with females performing worse than males (p = 0.03). Regarding other variables, education represented significant differences only in average scores of BD-Rel group (p = 0.01).

LIMITATIONS

Important attrition in BD-Rel group over time was detected, which precluded analysis at T3.

CONCLUSIONS

BD patients show significant deficits in VM that remain stable over time, even after controlling sociodemographic and clinical variables. Unaffected relatives also show stable deficits in VM. Accordingly, the deficit in VM could be considered a potential endophenotype of BD, which in turn may be useful as a predictor of the evolution of the disease. Further studies are needed to confirm these findings.

Neurocognitive endophenotypes in schizophrenia and bipolar disorder: A systematic review of longitudinal family studies

Although there is substantial evidence supporting the existence of neurocognitive impairment in patients diagnosed with schizophrenia (SZ) and bipolar disorder (BD), few studies have explored the field from an endophenotypic perspective. The present systematic review sought to identify longitudinal family studies exploring suitable neurocognitive endophenotypes in unaffected relatives of patients with SZ and/or BD. Following the PRISMA statement, only five follow-up studies met the inclusion criteria, comprising 79 SZ patients, 159 SZ unaffected relatives of SZ, 131 BD patients, 77 unaffected relatives of BD, and 248 controls. Verbal memory, auditory attention, face memory and emotion processing were found as putative endophenotypic candidates for SZ, whereas this strategy identified none for BD. Substantial heterogeneity and lack of standardization in global neurocognitive assessment within this area should be pointed out; nevertheless, several candidate endophenotypes were identified for SZ, except for executive impairment.

Age-related deficits in intracortical myelination in young adults with bipolar disorder type I

BACKGROUND

Previous studies have implicated white-matter-related changes in the pathophysiology of bipolar disorder. However, most of what is known is derived from in vivo subcortical white-matter imaging or postmortem studies. In this study, we investigated whole-brain intracortical myelin (ICM) content in people with bipolar disorder type I and controls.

METHODS

Between Sept. 1, 2014, and Jan. 31, 2017, we used a 3 T General Electric scanner to collect T1-weighted images in 45 people with bipolar disorder type I and 60 controls aged 17 to 45 years using an optimized sequence that was sensitive to ICM content. We analyzed images using a surfacebased approach. We used general linear models with quadratic age terms to examine the signal trajectory of ICM across the age range.

RESULTS

In healthy controls, the T1-weighted signal followed an inverted-U trajectory over age; in people with bipolar disorder type I, the association between ICM and age followed a flat trajectory (p < 0.05, Bonferroni corrected). Exploratory analyses showed that ICM signal intensity was associated with duration of illness, age of onset, and anticonvulsant and antipsychotic use in people with bipolar disorder type I (p < 0.05, uncorrected).

LIMITATIONS

Because of the cross-sectional nature of the study, we were unable to comment on whether the effects were due to dysmyelination or demyelination in bipolar disorder.

CONCLUSION

This foundational study is, to our knowledge, the first to show global age-related deficits in ICM maturation throughout the cortex in bipolar disorder. Considering the impact of myelination on the maintenance of neural synchrony and the integrity of neural connections, this work may help us better understand the cognitive and behavioural deficits seen in bipolar disorder.

What specifically contributes to disturbed non-verbal fluency in patients with bipolar disorder: Ineffective performance initiation, slowed processing or lack of the execution strategy?

The study aimed at identifying the cognitive and clinical determinants of impaired design fluency in bipolar patients, with special reference to processing speed and performance strategy. A sample of bipolar disorder patients (BD, n = 45) and matched healthy controls (HC, n = 42) underwent the assessment of figural fluency, cognitive and manual speed, cognitive effort and affective state. An electronic version of design fluency test was applied, enabling assessment of performance speed, execution strategy and spontaneous fluctuations in production efficiency. Additional clinical variables were also controlled. BD patients produced significantly less unique designs, performed slower, utilized less effective strategy, their ability to concentrate designs production in the initial phase of performance was significantly reduced compared with HC. Regression analysis revealed that in BD patients design fluency main outcome was significantly predicted by slowed creation of designs and the number of hospitalizations, while in the HC group, the main fluency result was predicted only by the executive strategy indicators. Our study showed that non-verbal fluency in BD group was determined by essentially different neuropsychological functions than in healthy controls. Obtained findings confirm that cognitive slowdown should be an important goal of cognitive remediation and pharmacological interventions in bipolar disorder.

Decreased anterior cingulate activation in a motor task in youths with bipolar disorder

BACKGROUND

Bipolar disorder (BP) is characterized by abnormal shifts in mood between episodes of mania and severe depression, both of which have been linked with psychomotor disturbances. This study compares brain activation patterns in motor networks between euthymic youths with BP and healthy controls (HC) during the completion of a simple motor task.

METHODS

Thirty-five youths with BP and 35 HC (aged 10-19) completed a self-paced sequential bilateral finger-tapping task, consisting of a 4-minute scan block with alternating 20-second periods of either the tapping task (six blocks) or rest (six blocks), while undergoing functional magnetic resonance imaging. Clinical and behavioral symptoms were assessed using the Child Behavior Checklist (CBCL). A between-group whole-brain analysis compared activation pattern differences while controlling for effects of age and sex. Clusters meeting whole-brain false discovery rate (FDR) correction (qFDR < .05) were considered statistically significant. Post hoc analyses evaluating comorbid attention-deficit/hyperactivity disorder (ADHD) in the BP group were also conducted.

RESULTS

Significantly decreased activation was found in the anterior cingulate cortex (ACC) in youths with BP compared to HC. Furthermore, ACC activation was negatively correlated with CBCL mood dysregulation profile scores in the BP group. No significant differences in functional activation patterns were found between youths with BP and comorbid ADHD and those with only BP.

CONCLUSIONS

These findings suggest a potential common mechanism of impaired ACC modulation between emotion dysregulation and motor processing in youths with BP.

Staging, Neurocognition and Social Functioning in Bipolar Disorder

Introduction: Bipolar disorder (BD) is associated with significant neurocognitive and functional impairment, which may progress across stages. The 'latent stage' of BD remains understudied. This cross-sectional study assessed staging, neurocognition and social functioning among BD patients and their healthy siblings. Methods: Four groups were included: euthymic type I BD patients in the early (n = 25) and late (n = 23) stages, their healthy siblings (latent stage; n = 23) and healthy controls (n = 21). All 92 subjects underwent a comprehensive neuropsychological battery of processing speed, verbal learning/memory, visual memory, working memory, verbal fluency, executive cognition, and motor speed. Social functioning was assessed using the FAST scale. Results: Siblings' social functioning was identical to that of controls, and significantly better than both early- (p < 0.005) and late- (p < 0.001) stage patients. Although all patients were strictly euthymic, those at late stages had a significantly worse social functioning than early-stage patients (p < 0.001). Compared to controls, increasingly greater neurocognitive dysfunction was observed across stages of BD (F = 1.59; p = 0.005). Healthy siblings' performance lied between those of controls and patients, with deficits in tasks of processing speed, executive attention, verbal memory/learning, and visual memory. Both early- and late-stage patients had a more severe and widespread dysfunction than siblings, with no significant differences between them. Conclusions: Genetic vulnerability to BD-I seems to be associated with neurocognitive impairments, whereas social dysfunction would be the result of the clinical phenotype. Staging models of BD should take into account these divergent findings in the latent stage.