Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Schizophr Res ; 204: 245-252, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30150023

RESUMO

BACKGROUND: The relationship between poor insight and less favorable outcomes in schizophrenia has promoted research efforts to understand its neurobiological basis. Thus far, research on neural correlates of insight has been constrained by small samples, incomplete insight assessments, and a focus on frontal lobes. The purpose of this study was to examine associations of cortical thickness and subcortical volumes, with a comprehensive assessment of clinical insight, in a large sample of enduring schizophrenia patients. METHODS: Two dimensions of clinical insight previously identified by a factor analysis of 4 insight assessments were used: Awareness of Illness and Need for Treatment (AINT) and Awareness of Symptoms and Consequences (ASC). T1-weighted structural images were acquired on a 3 T MRI scanner for 110 schizophrenia patients and 69 healthy controls. MR images were processed using CIVET (version 2.0) and MAGeT and quality controlled pre and post-processing. Whole-brain and region-of-interest, vertex-wise linear models were applied between cortical thickness, and levels of AINT and ASC. Partial correlations were conducted between volumes of the amygdala, thalamus, striatum, and hippocampus and insight levels. RESULTS: No significant associations between both insight factors and cortical thickness were observed. Moreover, no significant associations emerged between subcortical volumes and both insight factors. CONCLUSIONS: These results do not replicate previous findings obtained with smaller samples using single-item measures of insight into illness, suggesting a limited role of neurobiological factors and a greater role of psychological processes in explaining levels of clinical insight.


Assuntos
Conscientização/fisiologia , Gânglios da Base/patologia , Córtex Cerebral/patologia , Autoavaliação Diagnóstica , Esquizofrenia/patologia , Esquizofrenia/fisiopatologia , Tálamo/patologia , Adolescente , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/patologia , Gânglios da Base/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/patologia , Feminino , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esquizofrenia/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Adulto Jovem
2.
Schizophr Res ; 193: 251-260, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28669589

RESUMO

Among individuals with psychosis, those with poor cognitive insight (lower Self-Reflectiveness, higher Self-Certainty) show volumetric reductions in cortical structure. We evaluated whether changes in cognitive insight are associated with progressive changes in cortical structure in first-episode psychosis (FEP) and control subjects. Beck Cognitive Insight Scale ratings and magnetic resonance imaging scans were acquired at baseline for 130 FEP and 52 controls, 59 FEP and 28 controls at 1-year, and 53 FEP and 20 controls at 2-years. Cortical thickness was computed across scans and analyzed with linear mixed models. At baseline, groups did not differ on Self-Reflectiveness or Self-Certainty. At baseline, higher Self-Reflectiveness significantly correlated with thinner right occipital cortex in FEP, and higher Self-Certainty was significantly negatively correlated with cortical thickness in left posterior cingulate in controls. Longitudinal analysis showed that Self-Reflectiveness and Self-Certainty did not change over time in either group. Interestingly, the lack of change in cognitive insight aligned with longitudinal cortical thickness results, where no interaction effects were seen with cortical thickness between time and either Self-Reflectiveness or Self-Certainty. Exploratory analyses with a reduced threshold found that in FEP, across all time-points, higher Self-Certainty associated with thinner cortex in left posterior cingulate/precuneus. Results suggest that the posterior cingulate may be a common neural correlate for Self-Certainty in FEP and non-clinical subjects.


Assuntos
Córtex Cerebral/patologia , Transtornos Cognitivos/etiologia , Transtornos Psicóticos , Adulto , Córtex Cerebral/diagnóstico por imagem , Transtornos Cognitivos/diagnóstico por imagem , Progressão da Doença , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/complicações , Transtornos Psicóticos/patologia , Transtornos Psicóticos/psicologia , Autorrelato , Fatores de Tempo , Adulto Jovem
4.
Schizophr Res ; 189: 146-152, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28169088

RESUMO

People with psychosis show deficits recognizing facial emotions and disrupted activation in the underlying neural circuitry. We evaluated associations between facial emotion recognition and cortical thickness using a correlation-based approach to map structural covariance networks across the brain. Fifteen people with an early psychosis provided magnetic resonance scans and completed the Penn Emotion Recognition and Differentiation tasks. Fifteen historical controls provided magnetic resonance scans. Cortical thickness was computed using CIVET and analyzed with linear models. Seed-based structural covariance analysis was done using the mapping anatomical correlations across the cerebral cortex methodology. To map structural covariance networks involved in facial emotion recognition, the right somatosensory cortex and bilateral fusiform face areas were selected as seeds. Statistics were run in SurfStat. Findings showed increased cortical covariance between the right fusiform face region seed and right orbitofrontal cortex in controls than early psychosis subjects. Facial emotion recognition scores were not significantly associated with thickness in any region. A negative effect of Penn Differentiation scores on cortical covariance was seen between the left fusiform face area seed and right superior parietal lobule in early psychosis subjects. Results suggest that facial emotion recognition ability is related to covariance in a temporal-parietal network in early psychosis.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/patologia , Reconhecimento Facial/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Transtornos da Percepção/etiologia , Transtornos Psicóticos/complicações , Adulto , Córtex Cerebral/diagnóstico por imagem , Expressão Facial , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Transtornos da Percepção/diagnóstico por imagem , Projetos Piloto , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/diagnóstico por imagem , Adulto Jovem
5.
Early Interv Psychiatry ; 11(6): 480-487, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-26456932

RESUMO

AIM: High rates of anxiety have been observed in youth at clinical high risk (CHR) of developing psychosis. In CHR, anxiety often co-occurs with depression, and there is inconsistent evidence on anxiety in relation to transition to psychosis. The aim of this study was to examine: (i) the prevalence of anxiety disorders in individuals at CHR; (ii) clinical differences between those with and without anxiety; and (iii) the association of baseline anxiety with later transition to psychosis. METHODS: The sample consisted of 765 CHR individuals and 280 healthy controls. CHR status was determined with the Structured Interview of Prodromal Syndromes, mood and anxiety diagnoses with the Structured Clinical Interview for DSM-IV Disorders, and severity of anxiety with the Social Interaction Anxiety Scale and Self-Rating Anxiety Scale. RESULTS: In the CHR sample, 51% met criteria for an anxiety disorder. CHR participants had significantly more anxiety diagnoses and severity than healthy controls. Anxiety was correlated to attenuated psychotic and negative symptoms in CHR and those with an anxiety disorder demonstrated more suspiciousness. CHR participants with obsessive-compulsive disorder (OCD) exhibited more severe symptomatology than those without OCD. An initial presentation of anxiety did not differ between those who did or did not transition to psychosis. CONCLUSIONS: In this large sample of individuals at CHR, anxiety is common and associated with more severe attenuated psychotic symptoms. Treatment not only to prevent or delay transition to psychosis but also to address presenting concerns, such as anxiety, is warranted.


Assuntos
Transtornos de Ansiedade/epidemiologia , Transtornos Psicóticos/epidemiologia , Adolescente , Estudos de Casos e Controles , Comorbidade , Feminino , Humanos , Masculino , Sintomas Prodrômicos , Transtornos Psicóticos/diagnóstico , Estados Unidos/epidemiologia , Adulto Jovem
6.
Schizophr Res ; 179: 91-96, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27720314

RESUMO

Cognitive insight is described as a balance between one's self-reflectiveness (recognition and correction of dysfunctional reasoning), and self-certainty (overconfidence). Neuroimaging studies have linked the ventrolateral prefrontal cortex (VLPFC) to cognitive insight in people with psychosis. However, the relationship between cognitive insight and structural connectivity between the VLPFC and other brain areas is unknown. Here, we investigated the modulation of cognitive insight on structural covariance networks involving the VLPFC in a first-episode psychosis sample. Fifteen patients with a first-episode psychosis provided magnetic resonance (MR) scans and completed the Beck Cognitive Insight Scale (BCIS). MR scans were also available for 15 historical controls. Seed-based analysis of structural covariance was conducted using the Mapping Anatomical Correlations Across the Cerebral Cortex (MACACC) methodology, whereby Pearson correlation coefficients were extracted between seed regions in left and right VLPFC and cortical thickness across the brain. Structural covariance maps between groups were compared at each vertex. In first-episode subjects, we evaluated the modulation of BCIS scores on cortical covariance between VLPFC and every other vertex. Findings showed no significant group difference between first-episode psychosis subjects and controls in thickness covariance seeded from left or right VLPFC. However, in first-episode psychosis subjects, a positive association with self-certainty was found in networks seeded from both left and right VLPFC with thickness in medial frontal cortex and right pars triangularis. No significant associations were found for self-reflectiveness. These results suggest that self-certainty, but not self-reflectiveness, positively modulated cortical covariance in a frontal network in patients with a first-episode psychosis.


Assuntos
Imageamento por Ressonância Magnética/métodos , Córtex Pré-Frontal/diagnóstico por imagem , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/fisiopatologia , Autoimagem , Adulto , Feminino , Humanos , Masculino , Projetos Piloto , Autoavaliação (Psicologia) , Adulto Jovem
7.
J Psychiatr Res ; 86: 46-54, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27898324

RESUMO

Among people with a first-episode of psychosis, those with poorer clinical insight show neuroanatomical abnormalities in frontal, temporal and parietal cortices compared to those with better clinical insight. Whether changes in clinical insight are associated with progressive structural brain changes is unknown. We aimed to evaluate 1) associations between clinical insight and cortical thickness at a baseline assessment, 2) covariation between clinical insight and cortical thickness across baseline, one-year and two-year follow-up assessments, and 3) the predictive value of clinical insight for cortical thickness at one-year and two-year follow-ups. Scale for the assessment of Unawareness of Mental Disorder ratings and magnetic resonance imaging scans were acquired at baseline, one-year, and two-year follow-ups in 128, 74, and 44 individuals with a first-episode psychosis, respectively. Cortical thickness metrics were then computed at baseline, one-year and two-year follow-ups and analyzed with linear mixed models. At baseline, clinical insight was not significantly associated with cortical thickness in any region. Longitudinal mixed effects models showed that a worsening in clinical insight between the one-year and two-year assessments was significantly associated with cortical thinning in dorsal pre-central and post-central gyri. Cortical thinning in left fusiform gyrus at two-years was predicted by poorer clinical insight at baseline. Results suggest that poor clinical insight soon after the onset of a first-episode psychosis may lead to progressive cortical changes in temporal lobe, while changes in clinical insight during the second year covary with cortical thinning in circumscribed dorsal frontal and parietal cortices.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Transtornos Psicóticos/diagnóstico por imagem , Adolescente , Adulto , Estudos Transversais , Progressão da Doença , Feminino , Seguimentos , Humanos , Modelos Lineares , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão , Prognóstico , Transtornos Psicóticos/terapia , Quebeque , Fatores Socioeconômicos , Fatores de Tempo , Adulto Jovem
8.
Psychiatry Res Neuroimaging ; 254: 3-9, 2016 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-27289213

RESUMO

Among people at genetic risk of schizophrenia, those who use cannabis show smaller thalamic and hippocampal volumes. We evaluated this relationship in people at clinical high risk (CHR) of psychosis. The Alcohol and Drug Use Scale was used to identify 132 CHR cannabis users, the majority of whom were non-dependent cannabis users, 387 CHR non-users, and 204 healthy control non-users, and all participants completed magnetic resonance imaging scans. Volumes of the thalamus, hippocampus and amygdala were extracted with FreeSurfer, and compared across groups. Comparing all CHR participants with healthy control participants revealed no significant differences in volumes of any ROI. However, when comparing CHR users to CHR non-users, a significant ROI×Cannabis group effect emerged: CHR users showed significantly smaller amygdala compared to CHR non-users. However, when limiting analysis to CHR subjects who reported using alcohol at a 'use without impairment' severity level, the amygdala effect was non-significant; rather, smaller hippocampal volumes were seen in CHR cannabis users compared to non-users. Controlling statistically for effects of alcohol and tobacco use rendered all results non-significant. These results highlight the importance of controlling for residual confounding effects of other substance use when examining the relationship between cannabis use and neural structure.


Assuntos
Tonsila do Cerebelo/patologia , Cannabis/efeitos adversos , Hipocampo/patologia , Transtornos Psicóticos/patologia , Tálamo/patologia , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
9.
Schizophr Res ; 174(1-3): 77-81, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27165121

RESUMO

BACKGROUND: Recent research suggests that a traumatic brain injury (TBI) can significantly increase the risk of later development of psychosis. However, it is unknown whether people at clinical high risk (CHR) of psychosis have experienced TBI at higher rates, compared to otherwise healthy individuals. This study evaluated the prevalence of mild TBI, whether it was related to past trauma and the relationship of mild TBI to later transition to psychosis. METHODS: Seven-hundred forty-seven CHR and 278 healthy controls (HC) were assessed on past history of mild TBI, age at first and last injury, severity of worst injury and number of injuries using the Traumatic Brain Injury Interview. Attenuated psychotic symptoms were assessed with the Scale of Psychosis-risk Symptoms. IQ was estimated using the Wechsler Abbreviated Scale of Intelligence and past trauma and bullying were recorded using the Childhood Trauma and Abuse Scale. RESULTS: CHR participants experienced a mild TBI more often than the HC group. CHR participants who had experienced a mild TBI reported greater total trauma and bullying scores than those who had not, and those who experienced a mild TBI and later made the transition to psychosis were significantly younger at the age at first and most recent injury than those who did not. CONCLUSION: A history of mild TBI is more frequently observed in CHR individuals than in HC. Inclusion or study of CHR youth with more severe TBI may provide additional insights on the relationship between TBI and later transition to psychosis in CHR individuals.


Assuntos
Lesões Encefálicas Traumáticas/complicações , Transtornos Psicóticos/complicações , Adolescente , Análise de Variância , Lesões Encefálicas Traumáticas/epidemiologia , Bullying , Criança , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/epidemiologia , Estudos Retrospectivos , Risco , Índice de Gravidade de Doença , Estresse Psicológico/complicações , Estresse Psicológico/epidemiologia , Escalas de Wechsler , Adulto Jovem
10.
Schizophr Res ; 172(1-3): 16-22, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26899212

RESUMO

Compared to non-clinical subjects, people with psychosis show poor cognitive insight as reflected in low Self-Reflectiveness and high Self-Certainty. Neuroimaging studies have reported that 1) low Self-Reflectiveness is associated with volumetric reductions in ventrolateral prefrontal cortex (VLPFC), 2) higher Self-Certainty is associated with volumetric reductions in hippocampus, and 3) higher Self-Certainty is associated with fractional anisotropy in the fornix, in people with psychosis. The aims of the current study were to expand on this research by 1) performing an exploratory whole-brain cortical thickness analysis of the neural correlates of cognitive insight, to reveal whether regions outside the VLPFC are important for cognitive insight, and 2) to evaluate associations between cognitive insight and subfields of the hippocampus, which are distinct, interacting, and have different functions. We also aimed to replicate previous research documenting associations between cognitive insight and 3) total hippocampal volumes and 4) fornix fractional anisotropy. Fifteen people with a first-episode psychosis completed the Beck Cognitive Insight Scale and provided magnetic resonance and diffusion tensor imaging scans. Cortical thickness and hippocampal volumes were analyzed in FreeSurfer, and fornixfractional anisotropy was analyzed in Diffusion Toolkit/TrackVis. Higher Self-Reflectiveness and lower Self-Certainty significantly associated with thickness and thinness in VLPFC, respectively, as well as thickness and thinness in widespread frontal, parietal and temporal cortices. No associations emerged between Self-Reflectiveness or Self-Certainty and hippocampal total or sub-field volumes, or fornix fractional anisotropy. Results suggest that the neural correlates of cognitive insight involve a network of frontal, temporal and parietal brain regions.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Cognição , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/psicologia , Autoimagem , Doença Aguda , Adulto , Antipsicóticos/uso terapêutico , Córtex Cerebral/patologia , Imagem de Tensor de Difusão , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/tratamento farmacológico , Transtornos Psicóticos/patologia , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/tratamento farmacológico , Esquizofrenia/patologia , Psicologia do Esquizofrênico , Adulto Jovem
11.
Psychiatry Res ; 230(3): 878-84, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26626949

RESUMO

Among people with psychosis, those with a history of cannabis use show better cognitive performance than those who are cannabis naïve. It is unknown whether this pattern is present in youth at clinical high risk (CHR) of psychosis. We evaluated relationships between IQ and cannabis use while controlling for use of other substances known to impact cognition in 678 CHR and 263 healthy control (HC) participants. IQ was estimated using the Vocabulary and Block Design subtests of the Wechsler Abbreviated Scale of Intelligence. Drug and alcohol use severity and frequency were assessed with the Alcohol and Drug Use Scale, and we inquired participants' age at first use. CHR were further separated into early and late age at onset of cannabis use sub-groups, and low-, moderate- and high-frequency sub-groups. No significant differences in IQ emerged between CHR or HC cannabis users vs. non-users, or between use frequency groups. CHR late-onset users showed significantly higher IQ than CHR early-onset users. Age at onset of cannabis use was significantly and positively correlated with IQ in CHR only. Results suggest that age at onset of cannabis may be a more important factor for IQ than use current use or use frequency in CHR.


Assuntos
Cognição/fisiologia , Inteligência/fisiologia , Fumar Maconha/psicologia , Transtornos Psicóticos/psicologia , Adolescente , Adulto , Idade de Início , Consumo de Bebidas Alcoólicas/psicologia , Criança , Feminino , Humanos , Testes de Inteligência , Masculino , Risco , Adulto Jovem
12.
Schizophr Res ; 169(1-3): 209-213, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26589390

RESUMO

In schizophrenia, four typical patterns of premorbid functioning have been observed: stable-good, stable-intermediate, poor-deteriorating and deteriorating. However, it is unknown whether similar patterns exist in those who are at clinical high risk (CHR) of psychosis. The aim of this study was to examine patterns of premorbid functioning in a large sample of individuals at CHR of psychosis and its association with symptoms, functioning, and conversion to psychosis. One-hundred sixty people at CHR of psychosis were assessed on premorbid functioning using the Premorbid Adjustment Scale. Poorer premorbid functioning was significantly correlated with worse negative symptom severity and lower social functioning. Cluster analysis was used to identify patterns of premorbid functioning. Results indicated three patterns of premorbid functioning in our CHR sample: stable-intermediate, stable-good, and deteriorating. The deteriorating group had more severe disorganization, worse negative symptoms, and poorer social functioning than the other groups. Participants who made the conversion to psychosis had significantly poorer premorbid functioning during adolescence compared to those who did not convert. These results suggest that those at a clinical high risk for psychosis display similar patterns in premorbid functioning as have been observed in those with a psychotic illness and that poor premorbid functioning may be a predictor of psychosis.


Assuntos
Sintomas Prodrômicos , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Adolescente , Adulto , Análise de Variância , Criança , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Ajustamento Social , Adulto Jovem
13.
BMC Psychiatry ; 15: 276, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26553191

RESUMO

BACKGROUND: Disruptions in thalamic functional connectivity have been observed in people with schizophrenia and in youth at clinical high risk (CHR) of psychosis. However, the impact of environmental risk factors for psychosis on thalamic dysconnectivity is poorly understood. We tested whether thalamic dysconnectivity is related to patterns of cannabis use in a CHR sample. METHODS: 162 CHR and 105 control participants were assessed on cannabis use severity, frequency, and age at onset of first use as part of the North American Prodrome Longitudinal Study and completed resting-state fMRI scans. Whole-brain thalamic functional connectivity maps were generated using individual subjects' anatomically defined thalamic seeds. RESULTS: Thalamic connectivity did not significantly correlate with current cannabis use severity or frequency in either CHR or controls. In CHR cannabis users, a significant correlation emerged between attenuated thalamic connectivity with left sensory/motor cortex and a younger age at onset of cannabis use. CHR who used cannabis before age 15 did not differ on thalamic connectivity as compared to CHR who used after age 15 or CHR who were cannabis naïve. No group differences in thalamic connectivity emerged when comparing CHR separated by moderate/high use frequency, low-frequency or cannabis naïve. CONCLUSIONS: Although a younger age at onset of cannabis use may be associated with disrupted thalamo-cortical coupling, cannabis use does not appear to be an identifying characteristic for thalamic connectivity in CHR with moderate/high use frequency compared to low-frequency users or CHR who are cannabis naïve.


Assuntos
Fumar Maconha/efeitos adversos , Transtornos Psicóticos/etiologia , Tálamo/efeitos dos fármacos , Adolescente , Idade de Início , Análise de Variância , Mapeamento Encefálico , Estudos de Casos e Controles , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Córtex Motor/fisiologia , Sintomas Prodrômicos , Transtornos Psicóticos/fisiopatologia , Fatores de Risco , Esquizofrenia/etiologia , Esquizofrenia/fisiopatologia , Tálamo/fisiologia , Adulto Jovem
14.
Psychiatry Res ; 233(3): 418-23, 2015 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-26210694

RESUMO

Meta-cognition is compromised in people with schizophrenia and people at clinical high risk (CHR) of psychosis. In the current work in a CHR sample, we hypothesized that meta-cognitive functions would correlate with cortical thickness in five brain regions implicated in the pathogenesis of psychosis: inferior and middle frontal cortices, anterior cingulate cortex, superior temporal cortex and insula. Secondly, we hypothesized that similar neural systems would underlie different meta-cognitive functions. Narratives were gathered for 29 youth at CHR of psychosis using a semi-structured interview. Four meta-cognitive functions within the narratives were measured with the Meta-cognition Assessment Scale and regressed on cortical thickness from our a priori regions of interest using FreeSurfer. Mapping statistics from our a priori regions of interest revealed that meta-cognition functions were associated with cortical thickness in inferior and middle frontal gyri, superior temporal cortex and insula. The distribution of cortical thickness was partially similar across the four MAS items. Results confirm our hypothesis that cortical thickness is significantly associated with meta-cognition in brain regions that consistently show gray matter reductions across the schizophrenia spectrum. Evidence for thickness covariation in a variety of regions suggests partial dependence in the neural architecture underlying various meta-cognitive functions in CHR.


Assuntos
Córtex Cerebral/patologia , Metacognição , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Adolescente , Mapeamento Encefálico/métodos , Feminino , Lobo Frontal/patologia , Giro do Cíngulo/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Metacognição/fisiologia , Tamanho do Órgão , Fatores de Risco , Lobo Temporal/patologia
15.
Schizophr Res ; 166(1-3): 65-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26004692

RESUMO

In people with psychoses, Self-Reflectiveness may rely on the right ventrolateral prefrontal cortex (VLPFC). We used functional magnetic resonance imaging (fMRI) and a novel virtual reality paradigm to evaluate the role of the VLPFC for Self-Reflectiveness in 25 first-episode of schizophrenia (FES) participants and 24 controls. Participants first viewed 20 characters each paired with a unique object/location, and later completed source memory judgements during fMRI scanning. Self-Reflectiveness, measured with the Beck Cognitive Insight Scale, was significantly and positively correlated to activation in bilateral VLPFC in FES, but not in controls, providing further evidence that the VLPFC supports Self-Reflectiveness in FES.


Assuntos
Cognição/fisiologia , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Autoimagem , Mapeamento Encefálico , Feminino , Humanos , Julgamento/fisiologia , Imageamento por Ressonância Magnética , Masculino , Memória/fisiologia , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Adulto Jovem
16.
J Nerv Ment Dis ; 203(5): 328-35, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25919383

RESUMO

In studies describing the long-term follow-up up of youth at clinical high risk (CHR) of psychosis, little attention has been given to details of specific prodromal symptoms. In this paper, we describe the prodromal symptoms of 764 CHR participants recruited in the multi-site North American Prodrome Longitudinal Study (NAPLS). Symptoms were rated on the Scale of Prodromal Symptoms (SOPS) at baseline and 6-, 12-, 18-, and 24-month follow-ups. Clinical outcome at the 2-year assessment was categorized as psychotic, prodromal progression, symptomatic or in remission. Most of the CHR sample (92%) met criteria for the attenuated positive symptoms syndrome (APSS). Significant improvements in SOPS symptoms were observed over time. Unusual thought content, disorganized communication, and overall ratings on disorganized symptoms differentiated those who transitioned to psychosis from the other clinical outcome groups. Suspiciousness and total positive symptoms differentiated those in remission from the other clinical outcome groups.


Assuntos
Diagnóstico Precoce , Sintomas Prodrômicos , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Transtorno da Personalidade Esquizotípica/diagnóstico , Transtorno da Personalidade Esquizotípica/psicologia , Adolescente , Adulto , Algoritmos , Estudos de Casos e Controles , Manual Diagnóstico e Estatístico de Transtornos Mentais , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Masculino , América do Norte , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Psicometria , Transtornos Psicóticos/genética , Remissão Espontânea , Medição de Risco , Esquizofrenia/genética , Transtorno da Personalidade Esquizotípica/genética , Adulto Jovem
17.
Neuroimage Clin ; 7: 336-46, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25610794

RESUMO

Source memory, the ability to identify the context in which a memory occurred, is impaired in schizophrenia and has been related to clinical symptoms such as hallucinations. The neurobiological underpinnings of this deficit are not well understood. Twenty-five patients with recent onset schizophrenia (within the first 4.5 years of treatment) and twenty-four healthy controls completed a source memory task. Participants navigated through a 3D virtual city, and had 20 encounters of an object with a person at a place. Functional magnetic resonance imaging was performed during a subsequent forced-choice recognition test. Two objects were presented and participants were asked to either identify which object was seen (new vs. old object recognition), or identify which of the two old objects was associated with either the person or the place being presented (source memory recognition). Source memory was examined by contrasting person or place with object. Both patients and controls demonstrated significant neural activity to source memory relative to object memory, though activity in controls was much more widespread. Group differences were observed in several regions, including the medial parietal and cingulate cortex, lateral frontal lobes and right superior temporal gyrus. Patients with schizophrenia did not differentiate between source and object memory in these regions. Positive correlations with hallucination proneness were observed in the left frontal and right middle temporal cortices and cerebellum. Patients with schizophrenia have a deficit in the neural circuits which facilitate source memory, which may underlie both the deficits in this domain and be related to auditory hallucinations.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiopatologia , Memória/fisiologia , Esquizofrenia/fisiopatologia , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Reconhecimento Psicológico/fisiologia , Interface Usuário-Computador , Adulto Jovem
18.
PLoS One ; 9(6): e101372, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24979583

RESUMO

BACKGROUND: Negative symptoms represent an unmet therapeutic need in many patients with schizophrenia. In an extension to our previous voxel-based morphometry findings, we employed a more specific, vertex-based approach to explore cortical thinning in relation to persistent negative symptoms (PNS) in non-affective first-episode of psychosis (FEP) patients to advance our understanding of the pathophysiology of primary negative symptoms. METHODS: This study included 62 non-affective FEP patients and 60 non-clinical controls; 16 patients were identified with PNS (i.e., at least 1 primary negative symptom at moderate or greater severity sustained for at least 6 consecutive months). Using cortical thickness analyses, we explored for differences between PNS and non-PNS patients as well as between each patient group and healthy controls; cut-off threshold was set at p<0.01, corrected for multiple comparisons. RESULTS: A thinner cortex prominently in the right superior temporal gyrus extending into the temporo-parietal junction (TPJ), right parahippocampal gyrus, and left orbital frontal gyrus was identified in PNS patients vs. non-PNS patients. Compared with healthy controls, PNS patients showed a thinner cortex prominently in the right superior temporal gyrus, right parahippocampal gyrus, and right cingulate; non-PNS patients showed a thinner cortex prominently in the parahippocampal gyrus bi-laterally. CONCLUSION: Cortical thinning in the early stages of non-affective psychosis is present in the frontal and temporo-parietal regions in patients with PNS. With these brain regions strongly related to social cognitive functioning, our finding suggests a potential link between primary negative symptoms and social cognitive deficits through common brain etiologies.


Assuntos
Lobo Parietal/patologia , Transtornos Psicóticos/patologia , Lobo Temporal/patologia , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Lobo Parietal/fisiopatologia , Transtornos Psicóticos/diagnóstico , Lobo Temporal/fisiopatologia
19.
Schizophr Res ; 156(2-3): 277-80, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24837058

RESUMO

Elevated rates of substance use (alcohol, tobacco, cannabis) have been reported in people at clinical high risk (CHR) of developing psychosis and there is some evidence that substance use may be higher in those who convert to a psychosis compared to non-converters. However little is known about the predictive value of substance use on risk of conversion to psychosis in those at CHR of psychosis. In the current study, 170 people at CHR of psychosis were assessed at baseline on severity of alcohol, tobacco and cannabis using the Alcohol and Drug Use Scale. Participants were recruited across three sites over a four year period as part of the Enhancing the Prospective Prediction of Psychosis (PREDICT) study. Predictors of conversion to psychosis were examined using Cox proportional hazards models. Results revealed that low use of alcohol, but neither cannabis use nor tobacco use at baseline, contributed to the prediction of psychosis in the CHR sample. Prediction algorithms incorporating combinations of additional baseline variables known to be associated with psychotic conversion may result in increased predictive power compared with substance use alone.


Assuntos
Transtornos Psicóticos/complicações , Transtornos Psicóticos/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/complicações , Adolescente , Adulto , Transtornos Relacionados ao Uso de Álcool/complicações , Algoritmos , Criança , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Masculino , Abuso de Maconha/complicações , Sintomas Prodrômicos , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Risco , Tabagismo/complicações , Adulto Jovem
20.
Psychiatry Clin Neurosci ; 68(9): 683-91, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24612152

RESUMO

AIM: Previous research has linked cognitive insight (a measure of self-reflectiveness and self-certainty) in psychosis with neurocognitive and neuroanatomical disturbances in the fronto-hippocampal neural network. The authors' goal was to use functional magnetic resonance imaging (fMRI) to investigate the neural correlates of cognitive insight during an external source memory paradigm in non-clinical subjects. METHODS: At encoding, 24 non-clinical subjects travelled through a virtual city where they came across 20 separate people, each paired with a unique object in a distinct location. fMRI data were then acquired while participants viewed images of the city, and completed source recognition memory judgments of where and with whom objects were seen, which is known to involve prefrontal cortex. Cognitive insight was assessed with the Beck Cognitive Insight Scale. RESULTS: External source memory was associated with neural activity in a widespread network consisting of frontal cortex, including ventrolateral prefrontal cortex (VLPFC), temporal and occipital cortices. Activation in VLPFC correlated with higher self-reflectiveness and activation in midbrain correlated with lower self-certainty during source memory attributions. Neither self-reflectiveness nor self-certainty significantly correlated with source memory accuracy. CONCLUSION: By means of virtual reality and in the context of an external source memory paradigm, the study identified a preliminary functional neural basis for cognitive insight in the VLPFC in healthy people that accords with our fronto-hippocampal theoretical model as well as recent neuroimaging data in people with psychosis. The results may facilitate the understanding of the role of neural mechanisms in psychotic disorders associated with cognitive insight distortions.


Assuntos
Córtex Cerebral/fisiologia , Cognição/fisiologia , Memória/fisiologia , Mesencéfalo/fisiologia , Adolescente , Adulto , Neuroimagem Funcional , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética , Masculino , Reconhecimento Psicológico/fisiologia , Interface Usuário-Computador , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...