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1.
Neuropsychobiology ; 83(1): 49-60, 2024.
Article in English | MEDLINE | ID: mdl-38253028

ABSTRACT

INTRODUCTION: Recall of autobiographical events has been found to be impaired in borderline personality disorder (BPD), but few studies have examined if this impairment has brain functional correlates. This study evaluated brain functional alterations during autobiographical recall using medication-naive adolescent patients to avoid potential confounding effects of treatment. METHODS: Thirty-two adolescent female patients with BPD who were never-medicated and without psychiatric comorbidity and 33 matched healthy females underwent fMRI while they viewed individualized cue words that evoked autobiographical memories. Control conditions included viewing non-memory-evoking cues and a low-level baseline (cross-fixation). RESULTS: During autobiographical recall, in comparison to the low-level baseline, the BPD patients showed increased brain activity in regions including the posterior hippocampus, the lingual and calcarine cortex, and the precuneus compared to the healthy controls. The BPD patients also showed a failure to deactivate the right dorsolateral prefrontal cortex during autobiographical recall. No patient-control differences were found when memory-evoking words were compared to non-memory-evoking words. DISCUSSION/CONCLUSIONS: This study finds evidence of hippocampal/lingual/calcarine/precuneus hyperactivation to stimuli that evoke autobiographical memories in patients with BPD. As the changes were seen in never-treated patients without other comorbidities, they could be considered intrinsic to the disorder. Our study also adds to existing evidence for failure of deactivation in BPD, this time outside the default mode network.


Subject(s)
Borderline Personality Disorder , Humans , Female , Adolescent , Brain/diagnostic imaging , Mental Recall/physiology , Brain Mapping , Magnetic Resonance Imaging
2.
Psychol Med ; 53(10): 4780-4787, 2023 07.
Article in English | MEDLINE | ID: mdl-35730237

ABSTRACT

BACKGROUND: The brain functional correlates of delusions have been relatively little studied. However, a virtual reality paradigm simulating travel on the London Underground has been found to evoke referential ideation in both healthy subjects and patients with schizophrenia, making brain activations in response to such experiences potentially identifiable. METHOD: Ninety patients with schizophrenia/schizoaffective disorder and 28 healthy controls underwent functional magnetic resonance imaging while they viewed virtual reality versions of full and empty Barcelona Metro carriages. RESULTS: Compared to the empty condition, viewing the full carriage was associated with activations in the visual cortex, the cuneus and precuneus/posterior cingulate cortex, the inferior parietal cortex, the angular gyrus and parts of the middle and superior temporal cortex including the temporoparietal junction bilaterally. There were no significant differences in activation between groups. Nor were there activations associated with referentiality or presence of delusions generally in the patient group. However, patients with persecutory delusions showed a cluster of reduced activation compared to those without delusions in a region in the right temporal/occipital cortex. CONCLUSIONS: Performance of the metro task is associated with a widespread pattern of activations, which does not distinguish schizophrenic patients and controls, or show an association with referentiality or delusions in general. However, the finding of a cluster of reduced activation close to the right temporoparietal junction in patients with persecutory delusions specifically is of potential interest, as this region is believed to play a role in social cognition.


Subject(s)
Psychotic Disorders , Schizophrenia , Humans , Delusions/diagnosis , Schizophrenia/complications , Magnetic Resonance Imaging/methods , Brain
3.
Psychol Med ; 53(15): 7106-7115, 2023 Nov.
Article in English | MEDLINE | ID: mdl-36987680

ABSTRACT

BACKGROUND: A leading theory of the negative symptoms of schizophrenia is that they reflect reduced responsiveness to rewarding stimuli. This proposal has been linked to abnormal (reduced) dopamine function in the disorder, because phasic release of dopamine is known to code for reward prediction error (RPE). Nevertheless, few functional imaging studies have examined if patients with negative symptoms show reduced RPE-associated activations. METHODS: Matched groups of DSM-5 schizophrenia patients with high negative symptom scores (HNS, N = 27) or absent negative symptoms (ANS, N = 27) and healthy controls (HC, N = 30) underwent fMRI scanning while they performed a probabilistic monetary reward task designed to generate a measure of RPE. RESULTS: In the HC, whole-brain analysis revealed that RPE was positively associated with activation in the ventral striatum, the putamen, and areas of the lateral prefrontal cortex and orbitofrontal cortex, among other regions. Group comparison revealed no activation differences between the healthy controls and the ANS patients. However, compared to the ANS patients, the HNS patients showed regions of significantly reduced activation in the left ventrolateral and dorsolateral prefrontal cortex, and in the right lingual and fusiform gyrus. HNS and ANS patients showed no activation differences in ventral striatal or midbrain regions-of-interest (ROIs), but the HNS patients showed reduced activation in a left orbitofrontal cortex ROI. CONCLUSIONS: The findings do not suggest that a generalized reduction of RPE signalling underlies negative symptoms. Instead, they point to a more circumscribed dysfunction in the lateral frontal and possibly the orbitofrontal cortex.


Subject(s)
Schizophrenia , Humans , Schizophrenia/diagnostic imaging , Dopamine , Reward , Brain/diagnostic imaging , Frontal Lobe , Magnetic Resonance Imaging
4.
Psychol Med ; 53(7): 3065-3076, 2023 May.
Article in English | MEDLINE | ID: mdl-35574736

ABSTRACT

BACKGROUND: Deficits in emotional intelligence (EI) were detected in patients with bipolar disorder (BD), but little is known about whether these deficits are already present in patients after presenting a first episode mania (FEM). We sought (i) to compare EI in patients after a FEM, chronic BD and healthy controls (HC); (ii) to examine the effect exerted on EI by socio-demographic, clinical and neurocognitive variables in FEM patients. METHODS: The Emotional Intelligence Quotient (EIQ) was calculated with the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Performance on MSCEIT was compared among the three groups using generalized linear models. In patients after a FEM, the influence of socio-demographic, clinical and neurocognitive variables on the EIQ was examined using a linear regression model. RESULTS: In total, 184 subjects were included (FEM n = 48, euthymic chronic BD type I n = 75, HC n = 61). BD patients performed significantly worse than HC on the EIQ [mean difference (MD) = 10.09, standard error (s.e.) = 3.14, p = 0.004] and on the understanding emotions branch (MD = 7.46, s.e. = 2.53, p = 0.010). FEM patients did not differ from HC and BD on other measures of MSCEIT. In patients after a FEM, EIQ was positively associated with female sex (ß = -0.293, p = 0.034) and verbal memory performance (ß = 0.374, p = 0.008). FEM patients performed worse than HC but better than BD on few neurocognitive domains. CONCLUSIONS: Patients after a FEM showed preserved EI, while patients in later stages of BD presented lower EIQ, suggesting that impairments in EI might result from the burden of disease and neurocognitive decline, associated with the chronicity of the illness.


Subject(s)
Bipolar Disorder , Humans , Female , Bipolar Disorder/psychology , Mania , Emotional Intelligence , Emotions , Cognition
5.
Acta Psychiatr Scand ; 146(1): 36-50, 2022 07.
Article in English | MEDLINE | ID: mdl-35170748

ABSTRACT

OBJECTIVE: This study was aimed at identifying differences in the prodromal symptoms and their duration, risk factors and markers of vulnerability in patients presenting a first episode mania (FEM) or psychosis (FEP) with onset in late adolescence or adulthood in order to guide tailored treatment strategies. METHODS: Patients with a FEM or FEP underwent a clinical assessment. Prodromes were evaluated with the Bipolar Prodrome Symptom Scale-Retrospective (BPSS-R). Chi-squared tests were conducted to assess specific prodromal symptoms, risk factors or markers of vulnerability between groups. Significant prodromal symptoms were entered in a stepwise forward logistic regression model. The probabilities of a gradual versus rapid onset pattern of the prodromes were computed with logistic regression models. RESULTS: The total sample included 108 patients (FEM = 72, FEP = 36). Social isolation was associated with the prodromal stage of a FEP whilst Increased energy or goal-directed activity with the prodrome to a FEM. Physically slowed down presented the most gradual onset whilst Increased energy presented the most rapid. The presence of obstetric complications and difficulties in writing and reading during childhood were risk factors for FEP. As for markers of vulnerability, impairment in premorbid adjustment was characteristic of FEP patients. No specific risk factor or marker of vulnerability was identified for FEM. CONCLUSION: Early characteristics differentiating FEP from FEM were identified. These findings might help shape early identification and preventive intervention programmes.


Subject(s)
Prodromal Symptoms , Psychotic Disorders , Adolescent , Adult , Humans , Mania , Psychotic Disorders/diagnosis , Retrospective Studies , Risk Factors
6.
Eur Arch Psychiatry Clin Neurosci ; 272(7): 1229-1239, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35796825

ABSTRACT

The CACNA1C and the ZNF804A genes are among the most relevant schizophrenia GWAS findings. Recent evidence shows that the interaction of these genes with the schizophrenia diagnosis modulates brain functional response to a verbal fluency task. To better understand how these genes might influence the risk for schizophrenia, we aimed to study the interplay between CACNA1C and ZNF804A on working memory brain functional correlates. The analyses included functional and behavioural N-back task data (obtained from an fMRI protocol) and CACNA1C-rs1006737 and ZNF804A-rs1344706 genotypes for 78 healthy subjects and 78 patients with schizophrenia (matched for age, sex and premorbid IQ). We tested the effects of the epistasis between these genes as well as of the three-way interaction (CACNA1C × ZNAF804A × diagnosis) on working memory-associated activity (N-back: 2-back vs 1-back). We detected a significant CACNA1C × ZNAF804A interaction on working memory functional response in regions comprising the ventral caudate medially and within the left hemisphere, the superior and inferior orbitofrontal gyrus, the superior temporal pole and the ventral-anterior insula. The individuals with the GWAS-identified risk genotypes (CACNA1C-AA/AG and ZNF804A-AA) displayed a reduced working memory modulation response. This genotypic combination was also associated with opposite brain activity patterns between patients and controls. While further research will help to comprehend the neurobiological mechanisms of this interaction, our data highlight the role of the epistasis between CACNA1C and ZNF804A in the functional mechanisms underlying the pathophysiology of schizophrenia.


Subject(s)
Schizophrenia , Calcium Channels, L-Type/genetics , Functional Neuroimaging , Genetic Predisposition to Disease/genetics , Genome-Wide Association Study , Genotype , Humans , Kruppel-Like Transcription Factors/genetics , Polymorphism, Single Nucleotide/genetics , Schizophrenia/diagnostic imaging , Schizophrenia/genetics
7.
Int J Mol Sci ; 23(13)2022 Jul 05.
Article in English | MEDLINE | ID: mdl-35806464

ABSTRACT

Included in the neurotrophins family, the Neuritin 1 gene (NRN1) has emerged as an attractive candidate gene for schizophrenia (SZ) since it has been associated with the risk for the disorder and general cognitive performance. In this work, we aimed to further investigate the association of NRN1 with SZ by exploring its role on age at onset and its brain activity correlates. First, we developed two genetic association analyses using a family-based sample (80 early-onset (EO) trios (offspring onset ≤ 18 years) and 71 adult-onset (AO) trios) and an independent case-control sample (120 healthy subjects (HS), 87 EO and 138 AO patients). Second, we explored the effect of NRN1 on brain activity during a working memory task (N-back task; 39 HS, 39 EO and 39 AO; matched by age, sex and estimated IQ). Different haplotypes encompassing the same three Single Nucleotide Polymorphisms(SNPs, rs3763180-rs10484320-rs4960155) were associated with EO in the two samples (GCT, TCC and GTT). Besides, the GTT haplotype was associated with worse N-back task performance in EO and was linked to an inefficient dorsolateral prefrontal cortex activity in subjects with EO compared to HS. Our results show convergent evidence on the NRN1 association with EO both from genetic and neuroimaging approaches, highlighting the role of neurotrophins in the pathophysiology of SZ.


Subject(s)
GPI-Linked Proteins , Neuropeptides , Schizophrenia , Adult , GPI-Linked Proteins/genetics , Humans , Magnetic Resonance Imaging , Memory, Short-Term/physiology , Nerve Growth Factors/genetics , Neuroimaging , Neuropeptides/genetics , Polymorphism, Single Nucleotide , Prefrontal Cortex , Schizophrenia/diagnosis , Schizophrenia/genetics
8.
Psychol Med ; 51(1): 121-128, 2021 01.
Article in English | MEDLINE | ID: mdl-31680659

ABSTRACT

BACKGROUND: The brain functional correlates of autobiographical recall are well established, but have been little studied in schizophrenia. Additionally, autobiographical memory is one of a small number of cognitive tasks that activates rather than de-activates the default mode network, which has been found to be dysfunctional in this disorder. METHODS: Twenty-seven schizophrenic patients and 30 healthy controls underwent functional magnetic resonance imaging while viewing cue words that evoked autobiographical memories. Control conditions included both non-memory-evoking cues and a low level baseline (cross fixation). RESULTS: Compared to both non-memory evoking cues and low level baseline, autobiographical recall was associated with activation in default mode network regions in the controls including the medial frontal cortex, the posterior cingulate cortex and the hippocampus, as well as other areas. Clusters of de-activation were seen outside the default mode network. There were no activation differences between the schizophrenic patients and the controls, but the patients showed clusters of failure of de-activation in non-default mode network regions. CONCLUSIONS: According to this study, patients with schizophrenia show intact activation of the default mode network and other regions associated with recall of autobiographical memories. The finding of failure of de-activation outside the network suggests that schizophrenia may be associated with a general difficulty in de-activation rather than dysfunction of the default mode network per se.


Subject(s)
Default Mode Network/physiopathology , Memory, Episodic , Schizophrenia/physiopathology , Schizophrenic Psychology , Adult , Aged , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged
9.
Psychol Med ; 50(10): 1746-1754, 2020 07.
Article in English | MEDLINE | ID: mdl-31456534

ABSTRACT

BACKGROUND: Although executive and other cognitive deficits have been found in patients with borderline personality disorder (BPD), whether these have brain functional correlates has been little studied. This study aimed to examine patterns of task-related activation and de-activation during the performance of a working memory task in patients with the disorder. METHODS: Sixty-seven DSM-IV BPD patients and 67 healthy controls underwent fMRI during the performance of the n-back task. Linear models were used to obtain maps of within-group activations and areas of differential activation between the groups. RESULTS: On corrected whole-brain analysis, there were no activation differences between the BPD patients and the healthy controls during the main 2-back v. baseline contrast, but reduced activation was seen in the precentral cortex bilaterally and the left inferior parietal cortex in the 2-back v. 1-back contrast. The patients showed failure of de-activation affecting the medial frontal cortex and the precuneus, plus in other areas. The changes did not appear to be attributable to previous history of depression, which was present in nearly half the sample. CONCLUSIONS: In this study, there was some, though limited, evidence for lateral frontal hypoactivation in BPD during the performance of an executive task. BPD also appears to be associated with failure of de-activation in key regions of the default mode network.


Subject(s)
Borderline Personality Disorder/physiopathology , Default Mode Network/physiopathology , Parietal Lobe/physiopathology , Adult , Brain Mapping , Case-Control Studies , Female , Humans , Magnetic Resonance Imaging/instrumentation , Magnetic Resonance Imaging/methods , Male , Memory, Short-Term , Spain , Young Adult
11.
Psychiatry Res ; 339: 116027, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38954892

ABSTRACT

Given the shared ectodermal origin and integrated development of the face and the brain, facial biomarkers emerge as potential candidates to assess vulnerability for disorders in which neurodevelopment is compromised, such as schizophrenia (SZ) and bipolar disorder (BD). The sample comprised 188 individuals (67 SZ patients, 46 BD patients and 75 healthy controls (HC)). Using a landmark-based approach on 3D facial reconstructions, we quantified global and local facial shape differences between SZ/BD patients and HC using geometric morphometrics. We also assessed correlations between facial and brain cortical measures. All analyses were performed separately by sex. Diagnosis explained 4.1 % - 5.9 % of global facial shape variance in males and females with SZ, and 4.5 % - 4.1 % in BD. Regarding local facial shape, we detected 43.2 % of significantly different distances in males and 47.4 % in females with SZ as compared to HC, whereas in BD the percentages decreased to 35.8 % and 26.8 %, respectively. We detected that brain area and volume significantly explained 2.2 % and 2 % of facial shape variance in the male SZ - HC sample. Our results support facial shape as a neurodevelopmental marker for SZ and BD and reveal sex-specific pathophysiological mechanisms modulating the interplay between the brain and the face.

12.
Article in English | MEDLINE | ID: mdl-38325744

ABSTRACT

Different lines of evidence indicate that the structure and physiology of the basal ganglia and the thalamus is disturbed in schizophrenia. However, it is unknown whether the volume and shape of these subcortical structures are affected in schizophrenia with auditory hallucinations (AH), a core positive symptom of the disorder. We took structural MRI from 63 patients with schizophrenia, including 36 patients with AH and 27 patients who had never experienced AH (NAH), and 51 matched healthy controls. We extracted volumes for the left and right thalamus, globus pallidus, putamen, caudate and nucleus accumbens. Shape analysis was also carried out. When comparing to controls, the volume of the right globus pallidus, thalamus, and putamen, was only affected in AH patients. The volume of the left putamen was also increased in individuals with AH, whereas the left globus pallidus was affected in both groups of patients. The shapes of right and left putamen and thalamus were also affected in both groups. The shape of the left globus pallidus was only altered in patients lacking AH, both in comparison to controls and to cases with AH. Lastly, the general PANSS subscale was correlated with the volume of the right thalamus, and the right and left putamen, in patients with AH. We have found volume and shape alterations of many basal ganglia and thalamus in patients with and without AH, suggesting in some cases a possible relationship between this positive symptom and these morphometric alterations.


Subject(s)
Schizophrenia , Humans , Schizophrenia/complications , Schizophrenia/diagnostic imaging , Basal Ganglia/diagnostic imaging , Thalamus/diagnostic imaging , Putamen/diagnostic imaging , Hallucinations/diagnostic imaging , Magnetic Resonance Imaging
13.
Schizophr Res ; 266: 50-57, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38368705

ABSTRACT

BACKGROUND: Schizophrenic symptoms are known to segregate into reality distortion, negative and disorganization syndromes, but the correlates of these syndromes with regional brain structural change are not well established. Cognitive impairment is a further clinical feature of schizophrenia, whose brain structural correlates are the subject of conflicting findings. METHODS: 165 patients with schizophrenia were rated for symptoms using the PANSS, and cognitive impairment was indexed by estimated premorbid-current IQ discrepancy. Cortical volume was measured using surface-based morphometry in the patients and in 50 healthy controls. Correlations between clinical and cognitive measures and cortical volume were examined using whole-brain FreeSurfer tools. RESULTS: No clusters of volume reduction were seen associated with reality distortion or disorganization. Negative symptom scores showed a significant inverse correlation with volume in a small cluster in the left medial orbitofrontal gyrus. Larger estimated premorbid-current IQ discrepancies were associated with clusters of reduced cortical volume in the left precentral gyrus and the left temporal lobe. The cluster of association with negative symptoms disappeared when estimated premorbid-current IQ discrepancy was controlled for. CONCLUSIONS: This study does not provide support for an association between brain structural abnormality and reality distortion or disorganization syndromes in schizophrenia. The cluster of volume reduction found in the left medial orbitofrontal cortex correlated with negative symptoms may have reflected the association between this class of symptoms and cognitive impairment. The study adds to existing findings of an association between cognitive impairment and brain structural changes in the disorder.


Subject(s)
Cognitive Dysfunction , Schizophrenia , Humans , Schizophrenia/complications , Schizophrenia/diagnostic imaging , Brain , Frontal Lobe , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/etiology , Temporal Lobe , Magnetic Resonance Imaging
14.
Psychol Trauma ; 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38512168

ABSTRACT

OBJECTIVE: This study aimed to assess the relationship between childhood maltreatment (CM), objective and subjective cognition, and psychosocial functioning in adults with first-episode psychosis (FEP) by examining the moderating role of cognitive reserve (CR). A secondary objective was to explore whether unique CM subtypes (physical and/or emotional abuse, sexual abuse, physical and/or emotional neglect) were driving this relationship. METHOD: Sixty-six individuals with FEP (Mage = 27.3, SD = 7.2 years, 47% male) completed a comprehensive neuropsychological test battery, the Cognitive Complaints in Bipolar Disorder Rating Assessment (COBRA), the Functioning Assessment Short Test (FAST), the Childhood Trauma Questionnaire (CTQ), and the Cognitive Reserve Assessment Scale in Health (CRASH). Linear regression analyses were conducted to evaluate the interaction effect of CR between CM and cognitive and psychosocial variables, controlling for age, sex, and social desirability (CTQ-denial-minimization). RESULTS: In adults with FEP overall CM interacted with CR to predict COBRA-subjective cognitive complaints, but not neurocognitive or psychosocial functioning. Sexual abuse and physical neglect interacted with CR to predict verbal memory. Most of the CM subtypes interacted with CR to predict FAST-leisure time, whereas only emotional neglect interacted with CR to predict FAST-interpersonal relationships. Overall, greater CR was related to better functioning. CONCLUSIONS: The current results indicate that associations between specific CM subtypes, subjective and objective cognition, and psychosocial domains are moderated through CR with greater functioning. Early interventions focused on CR seeking to improve cognitive and psychosocial outcomes, with emphasis on improving subjective cognitive functions would be beneficial for individuals with FEP and CM. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

15.
Neuropsychobiology ; 67(3): 181-4, 2013.
Article in English | MEDLINE | ID: mdl-23548794

ABSTRACT

BACKGROUND: Some functional imaging abnormalities found in bipolar disorder are state related, whereas others persist into euthymia. It is uncertain to what extent these latter changes may reflect continuing subsyndromal affective fluctuations and whether those can be modulated by therapeutic interventions. METHOD: We report functional magnetic resonance imaging (fMRI) findings during performance of the n-back working memory task in a bipolar patient who showed a marked improvement in subsyndromal affective symptoms after receiving eye movement desensitization and reprocessing (EMDR) therapy in the context of a clinical trial. RESULTS: The patient's clinical improvement was accompanied by marked changes in functional imaging, as compared to 30 healthy subjects. fMRI changes were noted particularly in deactivation, with failure of deactivation in the medial frontal cortex partially normalizing after treatment. CONCLUSIONS: This case supports the potential therapeutic overall benefit of EMDR in traumatized bipolar patients and suggests a possible neurobiological mechanism of action: normalization of default mode network dysfunction.


Subject(s)
Bipolar Disorder/therapy , Eye Movement Desensitization Reprocessing/methods , Nerve Net/physiopathology , Prefrontal Cortex/physiopathology , Adult , Bipolar Disorder/physiopathology , Clinical Trials as Topic , Female , Humans , Life Change Events , Magnetic Resonance Imaging , Memory, Short-Term/physiology , Neuropsychological Tests , Treatment Outcome
16.
J Psychiatr Res ; 161: 40-47, 2023 05.
Article in English | MEDLINE | ID: mdl-36898325

ABSTRACT

BACKGROUND: Patients with borderline personality disorder (BPD) have been found to show functional brain abnormality, including in the medial frontal cortex and other areas of the default mode network (DMN). The current study aimed to examine activations and de-activations in drug treated and medication-free female adolescents with the disorder. METHODS: 39 DSM-5 adolescent female patients with BPD without psychiatric comorbidity and 31 matched healthy female adolescents underwent fMRI during the performance of 1-back and 2-back versions of the n-back working memory task. Linear models were used to obtain maps of within-group activations and de-activations and areas of differences between the groups. RESULTS: On corrected whole-brain analysis, the BPD patients showed failure to de-activate a region of the medial frontal cortex in the 2-back > 1-back comparison. The 30 never-medicated patients additionally showed a failure to de-activate the right hippocampus in the 2-back versus baseline contrast. CONCLUSIONS: Evidence of DMN dysfunction was observed in adolescent patients with BPD. Because the relevant medial frontal and hippocampal changes were seen in unmedicated young patients without comorbidity, they might be considered intrinsic to the disorder.


Subject(s)
Borderline Personality Disorder , Humans , Female , Adolescent , Default Mode Network , Brain/diagnostic imaging , Frontal Lobe/diagnostic imaging , Memory, Short-Term/physiology , Magnetic Resonance Imaging , Brain Mapping
17.
Psychiatry Res ; 319: 114981, 2023 01.
Article in English | MEDLINE | ID: mdl-36459807

ABSTRACT

The psychosocial functioning of individuals suffering from bipolar disorder (BD) has a significant impact on prognosis and quality of life. The aim of this study was to assess brain functional correlates of psychosocial functioning in BD individuals during the performance of a working memory task. Sixty-two subjects (31 euthymic BD individuals and 31 matched healthy controls) underwent structural and functional magnetic resonance imaging scanning while performing the 1- and 2-back versions of the n-back task (1-back and 2-back). The Functional Assessment Short Test (FAST) and its subdomains were used to assess functioning. Whole brain analysis revealed only overall activation differences between BD patients and healthy controls, but the patients showed failure of de-activation in the medial frontal cortex. Six clusters of significant inverse correlation with the FAST scores were found in the dorsolateral prefrontal cortex, the superior parietal cortex, and temporo-occipital regions bilaterally, and in the left inferior frontal cortex. Cognitive and occupational functioning were the subdomains most significantly associated with brain activation in these clusters. The results suggest that poor psychosocial functioning in BD individuals is associated with hypoactivation in a range of cortical regions, including the fronto-parietal working memory network and inferior temporo-occipital regions.


Subject(s)
Bipolar Disorder , Humans , Bipolar Disorder/psychology , Memory, Short-Term/physiology , Quality of Life , Brain/diagnostic imaging , Cognition/physiology , Magnetic Resonance Imaging , Prefrontal Cortex
18.
J Affect Disord ; 329: 307-314, 2023 05 15.
Article in English | MEDLINE | ID: mdl-36863465

ABSTRACT

INTRODUCTION: Few studies have examined the functional brain correlates of the performance of the Stroop task in bipolar disorder (BD). It is also not known whether it is associated with failure of de-activation in the default mode network, as has been found in studies using other tasks. METHODS: Twenty-four BD patients and 48 age, sex and educationally estimated intellectual quotient (IQ) matched healthy subjects (HS) underwent a functional MRI during performance of the counting Stroop task. Task-related activations (incongruent versus congruent condition) and de-activations (incongruent versus fixation) were examined using whole-brain, voxel-based methodology. RESULTS: Both the BD patients and the HS showed activation in a cluster encompassing the left dorsolateral and ventrolateral prefrontal cortex and the rostral anterior cingulate cortex and supplementary motor area, with no differences between them. The BD patients, however, showed significant failure of de-activation in the medial frontal cortex and the posterior cingulate cortex/precuneus. CONCLUSIONS: The failure to find activation differences between BD patients and controls suggests that the 'regulative' component of cognitive control remains intact in the disorder, at least outside episodes of illness. The failure of de-activation found adds to evidence documenting trait-like default mode network dysfunction in the disorder.


Subject(s)
Bipolar Disorder , Motor Cortex , Humans , Bipolar Disorder/psychology , Prefrontal Cortex/diagnostic imaging , Stroop Test , Magnetic Resonance Imaging/methods , Brain/diagnostic imaging , Brain Mapping
19.
Front Hum Neurosci ; 16: 878028, 2022.
Article in English | MEDLINE | ID: mdl-35634207

ABSTRACT

Regularization may be used as an alternative to dimensionality reduction when the number of variables in a model is much larger than the number of available observations. In a recent study from our group regularized regression was employed to quantify brain functional connectivity in a sample of healthy controls using a brain parcellation and resting state fMRI images. Here regularization is applied to evaluate resting state connectivity abnormalities at the voxel level in a sample of patients with schizophrenia. Specifically, ridge regression is implemented with different degrees of regularization. Results are compared to those delivered by the weighted global brain connectivity method (GBC), which is based on averaged bivariate correlations and from the non-redundant connectivity method (NRC), a dimensionality reduction approach that applies supervised principal component regressions. Ridge regression is able to detect a larger set of abnormally connected regions than both GBC and NRC methods, including schizophrenia related connectivity reductions in fronto-medial, somatosensory and occipital structures. Due to its multivariate nature, the proposed method is much more sensitive to group abnormalities than the GBC, but it also outperforms the NRC, which is multivariate too. Voxel based regularized regression is a simple and sensitive alternative for quantifying brain functional connectivity.

20.
Neuroimage Clin ; 34: 103007, 2022.
Article in English | MEDLINE | ID: mdl-35468569

ABSTRACT

Auditory verbal hallucinations (AVH) are a key symptom of schizophrenia (SZ) defined by anomalous perception of speech. Anomalies of processing external speech stimuli have also been reported in people with AVH, but it is unexplored which specific dimensions of language are processed differently. Using a speech perception task (passive listening), we here targeted the processing of deixis, a key dimension of language governing the contextual anchoring of speech in interpersonal context. We designed naturalistic speech stimuli that were either non-personal and fact-reporting ('low-deixis' condition), or else involved rich deictic devices such as the grammatical first and second persons, direct questions, and vocatives ('high-deixis'). We asked whether neural correlates of deixis obtained with fMRI would distinguish patients with and without frequent hallucinations (AVH + vs AVH-) from controls and each other. Results showed that high-deixis relative to low-deixis was associated with clusters of increased activation in the bilateral middle temporal gyri extending into the temporal poles and the inferior parietal cortex, in all groups. The AVH + and AVH- groups did not differ. When unifying them, the SZ group as a whole showed altered activity in the precuneus, midline regions and inferior parietal cortex. These results fail to confirm deictic processing anomalies specific to patients with AVH, but reveal such anomalies across SZ. Hypoactivation of this network may relate to a cognitive mechanism for attributing and anchoring thought and referential speech content in context.


Subject(s)
Schizophrenia , Speech Perception , Hallucinations/diagnostic imaging , Hallucinations/etiology , Humans , Linguistics , Magnetic Resonance Imaging , Schizophrenia/complications , Schizophrenia/diagnostic imaging , Speech Perception/physiology , Temporal Lobe
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