Bipolar disorder and schizophrenia share a similar deficit in semantic inhibition: a meta-analysis based on Hayling Sentence Completion Test performance

Neural correlates of semantic ambiguity resolution in paucisymptomatic bipolar disorder patients

In addition to symptoms specifically related to mood dysregulation, patients with bipolar disorder (BD) show frequent alterations in formal thought organization. A disruption in semantic processing, notably in semantic inhibition, is one of the possible mechanisms that might explain this modified organization. However, to date, little is known about these mechanisms and their underlying neural substrates. This study aimed to identify the neural correlates of the semantic inhibition process in BD patients in comparison to healthy controls. Seventeen BD patients and 17 matched controls were recruited and underwent a 3T MRI scan. A semantic ambiguity resolution task was used during the scan to explore semantic inhibition. Whole-brain analyses were conducted on 13 BD patients and 16 controls. When compared to controls, BD patients had stronger activation in the bilateral temporal areas and right middle frontal gyrus, and less activation in the right hippocampus, parahippocampal area, and bilateral precunei. The present study revealed an altered fronto-temporo-parietal semantic inhibition network in BD patients that could reflect compensative mechanisms or modified semantic processing inducing abnormal thought organization, which has a major impact on the occupational and social functioning of the BD population.

Effects of Cognitive Training Programs on Executive Function in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review

BACKGROUND

Autism Spectrum Disorder is often associated with deficits in executive functions (EFs), which is contributing significantly to individuals with ASD's difficulties in conducting an independent life, particularly considering social skills. Technologies offer promising opportunities to structure EF intervention programs for children on the autistic spectrum.

METHODS

This study aimed to review the effectiveness of randomized controlled trials or quasi-experimental studies of EF interventions delivered to children and young people (up to 23 years old) with a diagnosis of ASD. A special focus was dedicated to document the effectiveness of computerized and non-computerized cognitive training on (1) EFs and on (2) ASD symptomatology and social skills. Of 2601 studies retrieved, 19 fulfilled the inclusion criteria.

RESULTS

Most of the interventions identified were effective in enhancing EFs and reducing symptoms in children and young people with ASD. Limited evidence is available on their generalization to untrained skills (i.e., social abilities) as well as long-term effects.

CONCLUSIONS

There is growing evidence for overall effectiveness of EF training, particularly when computerized. However, caution should be taken when interpreting these findings owing to methodological limitations, the minimal number of papers retrieved, and a small samples of included studies.

Neurocognitive Impairments (NCI) in bipolar disorder: Comparison with schizophrenia and healthy controls

BACKGROUND

Neurocognitive impairments (NCI) are common in patients with bipolar I disorder. However, reports about the affected domains, outcomes and magnitude have been inconsistent. The aim of this study was to compare the magnitude (severity) and specificity (domains), of (NCI) in euthymic Bipolar I Disorder (BD) patients with a demographically and educationally matched sample of patients with schizophrenia in remission (SC) and healthy controls (HC).

METHODS

The Screen for Cognitive Impairment in Psychiatry (SCIP) was applied in this cross-sectional study, to all consecutive and consenting euthymic outpatients with bipolar I disorder (BD) (n = 76), remitted patients with schizophrenia (n = 130) and age and gender-matched healthy controls (HC) (n = 100). The cognitive tests done included Verbal List Learning-Immediate (VLT-I), Working Memory Test (WMT), Verbal Fluency Test (VFT), Verbal Learning Test-Delayed (VLT-D) and Processing Speed Test (PST). Within the bipolar group, the association between NCI and functioning was assessed.

RESULTS

There was a significant difference in the proportions of participants that had cognitive impairment from the 3 groups (37% (HC) vs. 71.1% (BD) vs. 91.5%(SC) (p=<0.001). The BD group in comparison to the HCs did worse on all domains of the SCIP except WMT and PST. The BD group was not significantly different from the SC group in all neuropsychological domains of the SCIP except WMT. BD group significantly functions better than the SC group. The severity of depressive symptomatology and VLT-I were independent predictors of functioning in the BD group.

CONCLUSION

Cognitive impairment affects almost all the neurocognitive domains of the BD group. The difference in NCI between euthymic BD patients and SC in remission are quantitative rather than qualitative.

Impaired Cognitive Abilities in Siblings of Patients with Temporal Lobe Epilepsy

PURPOSE

Patients with temporal lobe epilepsy (TLE) are at high risk of cognitive impairment. In addition to persistent seizures and antiepileptic drugs (AEDs), genetic factors also play an important role in the progression of cognitive deficits in TLE patients. Defining a cognitive endophenotype for TLE can provide information on the risk of cognitive impairment in patients. This study investigated the cognitive endophenotype of TLE by comparing neuropsychological function between patients with TLE, their unaffected siblings, and healthy control subjects.

PATIENTS AND METHODS

A total of 46 patients with TLE, 26 siblings, and 33 control subjects were recruited. Cognitive function (ie, general cognition, short- and long-term memory, attention, visuospatial and executive functions, and working memory) was assessed with a battery of neuropsychological tests. Differences between groups were evaluated by analysis of covariance, with age and years of education as covariates. The Kruskal-Wallis test was used to evaluate data that did not satisfy the homogeneity of variance assumption. Pairwise comparisons were adjusted by Bonferroni correction, with a significance threshold of P<0.05.

RESULTS

Patients with TLE showed deficits in the information test (P<0.001), arithmetic test (P=0.003), digit symbol substitution test (P=0.001), block design test (BDT; P=0.005), and backward digit span test (P=0.001) and took a longer time to complete the Hayling test Part A (P=0.011) compared to controls. Left TLE patients tended to have worse executive function test scores than right TLE patients. The siblings of TLE patients showed deficits in the BDT (P=0.006, Bonferroni-corrected) relative to controls.

CONCLUSION

Patients with TLE exhibit cognitive impairment. Executive function is worse in patients with left TLE than in those with right TLE. Siblings show impaired visuospatial function relative to controls. Thus, cognitive deficits in TLE patients have a genetic component and are independent of seizures or AED use.

Effectiveness of integrated psychological therapy on clinical, neuropsychological, emotional and functional outcome in schizophrenia: a RCT study

Background: Cognitive impairment is considered a central feature of schizophrenia (SZ) and several rehabilitation treatments have been developed to try to improve cognitive deficits.Aims: The aim of the present study was to analyze the effectiveness of integrated psychological therapy (IPT) compared with a standard treatment (TAU) in two groups of patients with SZ, using a comprehensive testing battery of clinical, cognitive, social cognition and functional outcome domains.Methods: Forty-one patients with SZ were assigned to IPT or TAU groups in a randomized controlled trial (RCT). Psychopathological, neuropsychological, emotional and functional outcome variables were assessed at baseline and after 36 weeks of treatment.Results: The IPT group showed significant improvements than the TAU group regarding clinical and functional outcome variables. Moreover, the IPT group improved significantly in the cognitive domains and emotional functioning. Finally, linear regression has highlighted that the improvement of cognitive variables depends on having done the IPT treatment.Conclusions: IPT seems to be effective in improving clinical, neuropsychological, emotional and functional outcome in chronic SZ inpatients. Further studies would be desirable to deepen the effectiveness of IPT in the field of the psychiatric rehabilitation pointing to the possibility of recovery from mental illness.

Bipolar disorder and obsessive compulsive disorder: The comorbidity does not further impair the neurocognitive profile

BACKGROUND

The comorbidity of bipolar disorder (BD) and obsessive-compulsive disorder (OCD) has been widely described. Several studies have investigated the cognitive profiles of BD and OCD patients, but studies that compare BD, BD-OCD, and OCD patients in neuropsychological domains do not exist. The purpose of this study was to compare set-shifting, decision making, and central coherence among BD, BD-OCD, and OCD patients.

METHODS

A battery of neuropsychological tests was administered to 68 patients (22 BD, 26 BD-OCD, 20 OCD). The Young Mania Rating Scale and Hamilton Depression Rating Scale were used to evaluate manic and depressive symptoms, and OCD severity was assessed with the Yale Brown Obsessive Compulsive Scale.

RESULTS

No significant differences emerged in decision-making and cognitive flexibility, whereas BD patients had lower scores in the Accuracy Index on Rey-Osterrieth Complex Figure Test and poor response speed on Hayling Sentence Completion Test Part A than OCD patients.

LIMITATIONS

The small sample size with different BD patients, the cross-sectional design, and the study clinical nature.

CONCLUSIONS

The most striking result is that, contrary to our hypothesis, comorbidity does not further impair the neurocognitive profile. The clinical relevance of our work could be a shift from the current cognitive rehabilitation model focusing on individualized pathways towards a new overlapping model for all three patient groups. This could make the cognitive rehabilitation faster and less costly. Notwithstanding, these disorders do not only need cognitive training but also various psycho-educative approaches and treatment according to their different clinical profile.

French Version of the Hayling Sentence Completion Test, Part I: Normative Data and Guidelines for Error Scoring

Objective

The Hayling Sentence Completion Test (HSCT) measures prepotent response inhibition, useful to assess inhibition deficit in a variety of clinical conditions. Despite its extensive use by numerous clinical and research groups in France, normative data for the HSCT are not yet available for French speakers.

Method

A French version of the HCST was administered to a sample of 426 healthy community-dwelling French speaking adults (20-87 years of age). Normative data were calculated using a regression-based approach.

Results

Regression analyses indicated that both age and education were associated with response latency and number of errors in the inhibition condition. Equations to calculate Z scores are provided for clinical use. In addition, we provided a clear guideline for the error scoring of the inhibition condition by establishing a corpus of errors adjusted for the linguistic and cultural realities of the French population. Using this guideline, a good inter-rater reliability was observed. Because of the restricted ranges of response latency and number of errors in the automatic condition, the relationship between these scores and demographic factors was not explored. By consequence, no norms were proposed for this condition.

Conclusions

We provide normative data of a French version of the HSCT for adults and elderly patients. These normative data obtained will be extremely useful for clinical practice and research purposes.

Semantic Ambiguity Resolution in Patients With Bipolar Disorder-An Event-Related Potential Study

Deficits in inhibitory function are assumed to underlie psychopathology in bipolar disorder (BD), especially in states of mania. A subdomain of inhibition, semantic inhibition (SI), referring to the suppression of irrelevant word meanings, may underlie formal thought disorder, such as flights of ideas. In the present study, we investigated SI in patients with BD during semantic ambiguity resolution using behavioral and event-related potential (ERP) measures. We presented 14 patients with BD with current manic, hypomanic, or mixed clinical states and 28 healthy controls sequentially with word triplets containing either a homonym (e.g., “organ”) or a comparable unambiguous word (e.g., “piano”). Participants were instructed to make a decision whether or not the target word was related to the meaning field of the first two words. The inappropriate homonym meaning had to be inhibited to correctly perform the target decision. In addition to reaction times (RT) and error rates (ER), the N400 ERP component to the target, an electrophysiological index of semantic processing, was analyzed as measure of the amount of SI that had taken place. Analyses of the behavioral data revealed that BD patients exhibited an overall worse performance in terms of RT and ER. In the ERP data, we found differences in N400 amplitude to ambiguous and unambiguous conditions over the right hemisphere in patients with BD depending on target congruence: In incongruent trials, N400 amplitude was smaller in ambiguous than in unambiguous words. In congruent trials, in contrast, N400 amplitude was larger in ambiguous than in unambiguous words. Such ERP differences between ambiguous and unambiguous words were absent in controls. We conclude that N400 amplitude differences in the ambiguous and unambiguous conditions of the BD group may reflect insufficient suppression of irrelevant homonym meanings in the right hemisphere. Disturbed SI processes might contribute to formal thought disorder in BD.

Modulation of the N400 component in relation to hypomanic personality traits in a word meaning ambiguity resolution task

AIM

High levels of hypomanic personality traits have been associated with an increased risk of developing bipolar disorder (BD). Changes in semantic content, impaired verbal associations, abnormal prosody, and abnormal speed of language are core features of BD, and are thought to be related to semantic processing abnormalities. In the present study, we used event-related potentials to investigate the relation between semantic processing (N400 component) and hypomanic personality traits.

METHODS

We assessed 65 healthy young adults on the Hypomanic Personality Scale (HPS). Event-related potentials were recorded during a semantic ambiguity resolution task exploring semantic ambiguity (polysemous word ending a sentence) and congruency (target word semantically related to the sentence).

RESULTS

As expected, semantic ambiguity and congruency both elicited an N400 effect across our sample. Correlation analyses showed a significant positive relationship between the Social Vitality subscore of the HPS and N400 modulation in the frontal region of interest in the incongruent unambiguous condition, and in the frontocentral region of interest in the incongruent ambiguous condition.

CONCLUSION

We found differences in semantic processing (i.e., detection of incongruence and semantic inhibition) in individuals with higher Social Vitality subscores. In the light of the literature, we discuss the notion that a semantic processing impairment could be a potential marker of vulnerability to BD, and one that needs to be explored further in this clinical population.

Neuropsychological Clustering in Bipolar and Major Depressive Disorder

OBJECTIVES

Cognitive dysfunction is a key feature of major depressive (MDD) and bipolar (BD) disorders. However, rather than a single cognitive profile corresponding to each diagnostic categories, recent studies have identified significant intra- and cross-diagnostic variability in patterns of cognitive impairment. The goal of this study was to contribute to the literature on cognitive heterogeneity in mood disorders by identifying cognitive subprofiles in a population of patients with MDD, BD type I, BD type II, and healthy adults.

METHODS

Participants completed a neuropsychological battery; scores were converted into Z-scores using normative data and submitted to hierarchical cluster analysis.

RESULTS

Three distinct neuropsychological clusters were identified: (1) a large cluster containing mostly control participants, as well as some patients with BD and MDD, who performed at above-average levels on all neuropsychological domains; (2) a cluster containing some patients from all diagnostic groups, as well as healthy controls, who performed worse than cluster 1 on most tasks, and showed impairments in motor inhibition and verbal fluency; (3) a cluster containing mostly patients with mood disorders with severe impairments in verbal inhibition and cognitive flexibility.

CONCLUSIONS

These findings revealed multiple cognitive profiles within diagnostic categories, as well as significant cross-diagnostic overlap, highlighting the importance of developing more specific treatment approaches which consider patients' demographic and cognitive profiles in addition to their diagnosis. (JINS, 2017, 23, 584-593).

Unveiling the relative efficacy, safety and tolerability of prophylactic medications for migraine: pairwise and network-meta analysis

BACKGROUND

A large number patients struggle with migraine which is classified as a chronic disorder. The relative efficacy, safety and tolerability of prophylactic medications for migraine play a key role in managing this disease.

METHODS

We conducted an extensive literature search for popular prophylactic medications that are used for migraine patients. Pairwise meta-analysis and network meta-analysis (NMA) were carried out sequentially for determining the relative efficacy, safety and tolerability of prophylactic medications. Summary effect for migraine headache days, headache frequency, at least 50% reduction in headache attacks, all-adverse events, nausea, somnolence, dizziness, withdrawal and withdrawal due to adverse events were produced by synthesizing both direct and indirect evidence.

RESULTS

Patients with three interventions exhibited significantly less average migraine headache days compared with those treated by placebo (topiramate, propranolol, divalproex). Moreover, topiramate and valproate exhibited a significantly increased likelihood of at least 50% reduction in migraine headache attacks compared to placebo. Patients with topiramate and propranolol also exhibited significantly reduced headache frequency compared to those with placebo. On the other hand, patients with divalproex exhibited significantly higher risk of nausea compared to those with placebo, topiramate, propranolol, gabapentin and amitriptyline. Finally, divalproex was associated with an increased risk of withdrawal compared to placebo and propranolol.

CONCLUSIONS

Topiramate, propranolol and divalproex may be more efficacious than other prophylactic medications. Besides, the safety and tolerability of divalproex should be further verified by future studies.

Hallucinations and inhibitory functioning in healthy young adults with high and low levels of hypomanic personality traits

INTRODUCTION

Hallucinations in schizophrenia and hallucination proneness in healthy young adults are associated with a common cognitive mechanism, namely impaired inhibitory control. Hallucinatory-like experiences also seem related to hypomanic symptoms in non-clinical participants; however, the mechanisms involved are unknown. We sought to examine self-reported hallucinatory/anomalous perceptual experiences in students selected for high versus low levels of hypomanic personality traits, and whether hypomania is characterised by deficient inhibitory control.

METHOD

Undergraduate students with either high (n = 26) or low (n = 28) scores on the Hypomanic Personality Scale-Revised (HPS-20) were compared on: (1) the Launay Slade Hallucination Scale-Revised (LSHS-R), a measure of hallucination proneness, (2) the Cardiff Anomalous Perceptions Scale (CAPS) and (3) the Inhibition of Currently Irrelevant Memories (ICIM) task, an index of intentional inhibition.

RESULTS

The high HPS group had higher total scores, as well as higher frequency (on CAPS only), intrusiveness and distress (CAPS) scores compared to the low HPS group. They also produced significantly more false alarms on the second run of the ICIM task than the low hypomania traits group.

CONCLUSIONS

Frequent, intrusive and distressing perceptual anomalies and proneness to hallucinations tend to occur in healthy individuals with hypomanic personality traits and may be associated with transient difficulties with inhibitory control. Inhibitory control may be a cognitive marker of vulnerability to hallucinations across diagnostic boundaries.

Cognitive control and schizophrenia: The greatest reliability of the Stroop task

Three components of cognitive inhibition were compared in patients with schizophrenia and healthy controls. Nineteen patients with schizophrenia were compared to 30 healthy controls, matched for age, sex, and educational level. Cognitive inhibition was examined by (i) access to relevant information (Reading with distraction task), (ii) suppression of no longer relevant information (Trail Making Test B), and (iii) restraint of cognitive resources to relevant information (Stroop Test, Hayling Sentence Completion Test, Go/No-Go Test). Beck Depression Inventory, and Positive and Negative Syndrome Scale were also used. Compared to healthy controls, patients with schizophrenia and stabilized for at least 6 months were slower in the inhibition condition at the Stroop task, read more distractors at the RWD, and made more perseverative errors at the TMT, even after controlling for age, Mini-Mental State Examination score, information speed processing, and accuracy. This difference remained significant after taking into account the level of depressive symptoms and the severity of psychotic symptoms. In multivariate analyses, only the Stroop interference index explained cognitive inhibition deficit in patients with schizophrenia. The abnormal cognitive inhibition process observed in patients with schizophrenia could therefore concerns the ability to restraint, rather than the access or the suppression processes.

Cognitive dysfunction in bipolar disorder and schizophrenia: a systematic review of meta-analyses

Cognitive impairment is a core feature of schizophrenia (SZ) and bipolar disorder (BD). A neurocognitive profile characterized by widespread cognitive deficits across multiple domains in the context of substantial intellectual impairment, which appears to antedate illness onset, is a replicated finding in SZ. There is no specific neuropsychological signature that can facilitate the diagnostic differentiation of SZ and BD, notwithstanding, neuropsychological deficits appear more severe in SZ. The literature in this field has provided contradictory results due to methodological differences across studies. Meta-analytic techniques may offer an opportunity to synthesize findings and to control for potential sources of heterogeneity. Here, we performed a systematic review of meta-analyses of neuropsychological findings in SZ and BD. While there is no conclusive evidence for progressive cognitive deterioration in either SZ or BD, some findings point to more severe cognitive deficits in patients with early illness onset across both disorders. A compromised pattern of cognitive functioning in individuals at familiar and/or clinical risk to psychosis as well as in first-degree relatives of BD patients suggests that early neurodevelopmental factors may play a role in the emergence of cognitive deficits in both disorders. Premorbid intellectual impairment in SZ and at least in a subgroup of patients with BD may be related to a shared genetically determined influence on neurodevelopment.

Neural correlates of generation and inhibition of verbal association patterns in mood disorders

OBJECTIVES

Thought disorders such as rumination or flight of ideas are frequent in patients with mood disorders, and not systematically linked to mood state. These symptoms point to anomalies in cognitive processes mediating the generation and control of thoughts; for example, associative thinking and inhibition. However, their neural substrates are not known.

METHOD

To obtain an ecological measure of neural processes underlying the generation and suppression of spontaneous thoughts, we designed a free word association task during fMRI allowing us to explore verbal associative patterns in patients with mood disorders and matched controls. Participants were presented with emotionally negative, positive or neutral words, and asked to produce two words either related or unrelated to these stimuli.

RESULTS

Relative to controls, patients produced a reverse pattern of answer typicality for the related vs unrelated conditions. Controls activated larger semantic and executive control networks, as well as basal ganglia, precuneus and middle frontal gyrus. Unlike controls, patients activated fusiform gyrus, parahippocampal gyrus and medial prefrontal cortex for emotional stimuli.

CONCLUSIONS

Mood disorder patients are impaired in automated associative processes, but prone to produce more unique/personal associations through activation of memory and self-related areas.

A hypothesis-driven pathway analysis reveals myelin-related pathways that contribute to the risk of schizophrenia and bipolar disorder

Schizophrenia (SZ) and bipolar disorder (BD) are both severe neuropsychiatric disorders with a strong and potential overlapping genetic background. Multiple lines of evidence, including genetic studies, gene expression studies and neuroimaging studies, have suggested that both disorders are closely related to myelin and oligodendrocyte dysfunctions. In the current study, we hypothesized that the holistic effect of the myelin-related pathway contributes to the genetic susceptibility to both SZ and BD. We extracted pathway data from the canonical pathway database, Gene Ontology (GO), and selected a 'compiled' pathway based on previous literature. We then performed hypothesis-driven pathway analysis on GWAS data from the Psychiatric Genomics Consortium (PGC). As a result, we identified three myelin-related pathways with a joint effect significantly associated with both disorders: 'Myelin sheath' pathway (P(SZ) = 2.45E-7, P(BD) = 1.22E-3), 'Myelination' pathway (P(SZ) = 2.10E-4, P(BD) = 2.53E-24), and 'Compiled' pathway (P(SZ) = 4.57E-8, P(BD) = 2.61E-9). In comparing the SNPs and genes in these three pathways across the two diseases, we identified a substantial overlap in nominally associated SNPs and genes, which could be susceptibility SNPs and genes for both disorders. From these observations, we propose that myelin-related pathways may be involved in the etiologies of both SZ and BD.