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2.
Psychiatry Res ; 332: 115718, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38198857

RESUMO

The Signature Biobank is a longitudinal repository of biospecimen, psychological, sociodemographic, and diagnostic data that was created in 2012. The Signature Consortium represents a group of approximately one hundred Quebec-based transdisciplinary clinicians and research scientists with various expertise in the field of psychiatry. The objective of the Signature Biobank is to investigate the multi-faceted underpinnings of psychiatric disorders among patients in crisis. The Signature Consortium is expanding and includes new active members that seek to highlight the contributions made by Signature Biobank since its inception. This article details our research protocol, directions, and summarizes contributions. To date, we have collected biological samples (n = 1,986), and questionnaire data (n = 2,085) from psychiatric emergency patients of the Institut universitaire en santé mentale de Montréal (Quebec, Canada), with a large proportion from whom both data types were collected (n = 1,926). In addition to this, a subsample of patients was followed-up at hospital discharge, and two additional outpatient clinic appointments (n = 958 with at least one follow-up). In addition, a socio-demographically matched comparison group of individuals who were not hospitalized for psychiatric disorders (n = 149) was recruited from the surrounding catchment area. To summarize, a systematic review of the literature shows that the Signature Biobank has contributed to better characterizing psychiatric comorbidities, biological profiles, and psychosocial functioning across some of the most common psychiatric disorders, including psychosis, mood, anxiety, and substance use disorders. The Signature Biobank is now one of the world's largest repositories of data collected from patients receiving care at a psychiatric emergency unit.


Assuntos
Psiquiatria , Transtornos Psicóticos , Transtornos Relacionados ao Uso de Substâncias , Humanos , Bancos de Espécimes Biológicos , Comorbidade , Transtornos Psicóticos/diagnóstico
3.
J Psychiatr Res ; 147: 183-189, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35051717

RESUMO

OBJECTIVE: Although schizophrenia patients are at a heightened risk of exhibiting violent behaviours compared to the general population, few functional neuroimaging studies have explored the aberrant neurocircuitry underpinning such behaviours. This study aimed to identify disrupted resting-state activity and functional connectivity in schizophrenia patients with a history of violence. METHODS: Resting state functional magnetic resonance imaging data was collected from 62 schizophrenia patients and 25 healthy controls. Voxel-wise analyses of fractional amplitude of low frequency fluctuations (fALFF) were implemented to investigate disrupted regional patterns of spontaneous brain activity. Brain regions which yielded significant differences between groups were subsequently used as data-driven seeds for functional connectivity analyses. Finally, significant alterations (activity and connectivity) were correlated with lifetime violent behaviours. RESULTS: When compared to healthy controls, schizophrenia patients exhibited reduced fALFF in multiple brain regions including the (subgenual) anterior cingulate cortex (ACC), posterior cingulate cortex, precuneus cortex and left lateral orbitofrontal cortex (OFC). Seed-to-voxel analyses yielded significantly enhanced connectivity between the ACC and left OFC. The heightened functional connectivity between the latter two regions predicted the number of violent behaviours reported by schizophrenia patients. CONCLUSION: The current study demonstrated that the functional connectivity of brain regions associated with emotion regulation is impaired in schizophrenia and associated with violent antecedents among patients. This result is consistent with predominant theoretical models proposing that the OFC plays a critical role in the neurobiology of violence.


Assuntos
Esquizofrenia , Encéfalo , Mapeamento Encefálico/métodos , Giro do Cíngulo , Humanos , Imageamento por Ressonância Magnética/métodos
4.
Front Psychiatry ; 11: 143, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32180744

RESUMO

Background: Despite individuals with schizophrenia being at an elevated risk of violence compared to the general population, limited efforts have been invested in investigating the neurobiological etiology explaining the increase. Among the few studies examining functional disruptions pertaining to violent schizophrenia patients using fMRI, only one study has considered functional connectivity. The current state of knowledge does not allow to infer deficits in functional connectivity specific to distinct cognitive/emotional states that have been associated with the emergence of violence in schizophrenia, such as negative emotion processing. This study sought to identify disrupted connectivity among men with schizophrenia and a history of violence (SCZ+V), compared to men with schizophrenia without a history of violence (SCZ-V) and healthy controls, during negative emotion processing using fMRI. Methods: Twenty SCZ+V, 19 SCZ-V, and 21 healthy men were scanned while viewing negative images. Results: Negative images elicited an increased connectivity between the dorsal anterior cingulate cortex (dACC) and the bilateral rostral prefrontal cortex (rPFC), as well as a decreased functional connectivity between the frontal regions (bilateral rPFC and dACC) and the putamen and hippocampus in SCZ+V men as compared to SCZ-V men and healthy controls. Concurrently, the centrality of the dACC within the network was reduced in SCV+V subjects. Conclusions: These results suggest an inefficient integration of the information by the dACC between frontal and limbic regions in SCZ+V men during negative emotion processing and highlight the importance of the ACC in the neurobiological bases of violent behavior in schizophrenia.

5.
Psychiatry Res Neuroimaging ; 286: 45-52, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-30897449

RESUMO

Schizophrenia is a severe psychiatric disorder characterized by important cognitive deficits, which ultimately compromise the patients' ability to make optimal decisions. Unfortunately, the neurobiological bases of impaired reward-related decision-making in schizophrenia have rarely been studied. The objective of this study is to examine the neural mechanisms involved in reward-related decision-making in schizophrenia, using functional magnetic resonance imaging (fMRI). Forty-seven schizophrenia patients (DSM-IV criteria) and 23 healthy subjects with no psychiatric disorders were scanned using fMRI while performing the Balloon Analogue Risk Task (BART). A rapid event-related fMRI paradigm was used, separating decision and outcome events. Between-group differences in grey matter volumes were assessed with voxel-based morphometry. During the reward outcomes, increased activations were observed in schizophrenia in the left anterior insula, the putamen, and frontal sub-regions. Reduced grey matter volumes were observed in the left anterior insula in schizophrenia which spatially overlapped with functional alterations. Finally, schizophrenia patients made fewer gains on the BART. The fact that schizophrenia patients had increased activations in sub-cortical regions such as the striatum and insula in response to reward events suggests that the impaired decision-making abilities of these patients are mostly driven by an overvaluation of outcome stimuli.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Corpo Estriado/diagnóstico por imagem , Tomada de Decisões/fisiologia , Neuroimagem/métodos , Recompensa , Esquizofrenia/diagnóstico por imagem , Adulto , Mapeamento Encefálico/métodos , Córtex Cerebral/fisiopatologia , Corpo Estriado/fisiopatologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Imagem Multimodal/métodos , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico
6.
Schizophr Res ; 197: 176-181, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29486956

RESUMO

Schizophrenia is a chronic and severe mental illness that poses significant challenges. While many pharmacological and psychosocial interventions are available, many treatment-resistant schizophrenia patients continue to suffer from persistent psychotic symptoms, notably auditory verbal hallucinations (AVH), which are highly disabling. This unmet clinical need requires new innovative treatment options. Recently, a psychological therapy using computerized technology has shown large therapeutic effects on AVH severity by enabling patients to engage in a dialogue with a computerized representation of their voices. These very promising results have been extended by our team using immersive virtual reality (VR). Our study was a 7-week phase-II, randomized, partial cross-over trial. Nineteen schizophrenia patients with refractory AVH were recruited and randomly allocated to either VR-assisted therapy (VRT) or treatment-as-usual (TAU). The group allocated to TAU consisted of antipsychotic treatment and usual meetings with clinicians. The TAU group then received a delayed 7weeks of VRT. A follow-up was ensured 3months after the last VRT therapy session. Changes in psychiatric symptoms, before and after TAU or VRT, were assessed using a linear mixed-effects model. Our findings showed that VRT produced significant improvements in AVH severity, depressive symptoms and quality of life that lasted at the 3-month follow-up period. Consistent with previous research, our results suggest that VRT might be efficacious in reducing AVH related distress. The therapeutic effects of VRT on the distress associated with the voices were particularly prominent (d=1.2). VRT is a highly novel and promising intervention for refractory AVH in schizophrenia.


Assuntos
Avaliação de Resultados em Cuidados de Saúde , Percepção da Fala/fisiologia , Terapia Assistida por Computador/métodos , Terapia de Exposição à Realidade Virtual/métodos , Adulto , Estudos Cross-Over , Feminino , Seguimentos , Alucinações , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Esquizofrenia
7.
Schizophr Res ; 197: 249-252, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29129509

RESUMO

We investigated the influence of anger processing on cognitive control in male schizophrenia patients presenting violent behaviors. We recruited 23 patients without and 24 patients with (SCZ+V) a history of violent behaviors, as well as 22 healthy non-violent men. Participants were administered an affective (angry-neutral faces) Go/NoGo task while undergoing functional magnetic resonance imaging. We found a reduced activation in the dorsolateral prefrontal cortex in SCZ+V patients specifically when inhibiting a response while viewing angry faces. These results show an inability of SCZ+V to recruit a core region of the (inhibitory) cognitive control network in the context of anger.


Assuntos
Ira/fisiologia , Função Executiva/fisiologia , Expressão Facial , Neuroimagem Funcional , Inibição Psicológica , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/fisiopatologia , Violência , Adolescente , Adulto , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/diagnóstico por imagem , Desempenho Psicomotor/fisiologia , Esquizofrenia/diagnóstico por imagem , Adulto Jovem
8.
Front Psychiatry ; 8: 109, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28674507

RESUMO

BACKGROUND: Cigarette smoking is highly prevalent in schizophrenia and is one of the main factors contributing to the significantly decreased life expectancy in this population. Schizophrenia smokers, compared to their counterparts with no comorbid psychiatric disorder, are largely unaware and indifferent to the long-term negative consequences of cigarette smoking. The objective of this study was to determine, for the first time, if these meta-cognitive deficits are associated with neuro-functional alterations in schizophrenia smokers. METHODS: Twenty-four smokers with no psychiatric disorder and 21 smokers with schizophrenia (DSM-IV criteria) were scanned using functional magnetic resonance imaging and exposed to anti-smoking images. Granger causality analyses were used to examine the effective connectivity between brain regions found to be significantly activated. RESULTS: Across groups, potent activations were observed in the left ventro-lateral prefrontal cortex, the left amygdala (AMG), and the dorsomedial prefrontal cortex (dmPFC). Using the dmPFC as a seed region, we found an abnormal negative connectivity from the dmPFC to the AMG in schizophrenia smokers during the viewing of anti-smoking stimuli. This abnormal connectivity was not present during the viewing of aversive stimuli unrelated to tobacco. DISCUSSION: Given the well-established roles of the dmPFC in social cognition and of the AMG in emotional processing, our results suggest that the relative indifference of schizophrenia smokers regarding the negative consequences of tobacco smoking could be explained by a cognitive-affective dissonance.

9.
Schizophr Res ; 188: 68-74, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28095997

RESUMO

Working memory deficits have been widely reported in schizophrenia, and may result from inefficient binding processes. These processes, and their neural correlates, remain understudied in schizophrenia. Thus, we designed an FMRI study aimed at investigating the neural correlates of both passive and active binding in working memory in schizophrenia. Nineteen patients with schizophrenia and 23 matched controls were recruited to perform a working memory binding task, in which they were instructed to memorize three letters and three spatial locations. In the passive binding condition, letters and spatial locations were directly presented as bound. Conversely, in the active binding condition, words and spatial locations were presented as separated, and participants were instructed to intentionally create associations between them. Patients exhibited a similar performance to the controls for the passive binding condition, but a significantly lower performance for the active binding. FMRI analyses revealed that this active binding deficit was related to aberrant activity in the posterior parietal cortex and the ventrolateral prefrontal cortex. This study provides initial evidence of a specific deficit for actively binding information in schizophrenia, which is linked to dysfunctions in the neural networks underlying attention, manipulation of information, and encoding strategies. Together, our results suggest that all these dysfunctions may be targets for neuromodulation interventions known to improve cognitive deficits in schizophrenia.


Assuntos
Aprendizagem por Associação/fisiologia , Memória de Curto Prazo/fisiologia , Lobo Parietal/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Adulto , Antipsicóticos/uso terapêutico , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Lobo Parietal/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/tratamento farmacológico , Memória Espacial/fisiologia
10.
Schizophr Res ; 173(1-2): 30-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27005897

RESUMO

BACKGROUND: Highly prevalent in schizophrenia, tobacco smoking substantially increases the risk of cardiac-related death. Compared to the general population, tobacco smoking cessation rates are lower in schizophrenia. Unfortunately, the reasons for these low cessation rates remain poorly understood. Recently, it has been shown that tobacco cravings are increased in schizophrenia smokers compared to smokers with no comorbid psychiatric disorder. In view of these results, we sought to examine - for the first time - the neurophysiologic responses elicited by cigarette cues in schizophrenia smokers. We hypothesized that cigarettes cues would elicit increased activations in brain regions involved in drug cravings in schizophrenia smokers relative to control smokers. METHODS: Smokers with (n=18) and without (n=24) schizophrenia (DSM-IV criteria) were scanned using functional magnetic resonance imaging (fMRI) while viewing appetitive cigarette images. RESULTS: Schizophrenia smokers and smokers with no psychiatric comorbidity did not differ in subjective cravings in response to appetitive smoking cues. However, in schizophrenia smokers relative to control smokers, we found that appetitive cigarette cues triggered increased activations of the bilateral ventro-medial prefrontal cortex, a core region of the brain reward system. Moreover, a negative correlation was observed between cigarette cravings and activations of the right ventro-medial prefrontal cortex in schizophrenia smokers. DISCUSSION: The current results highlight a key role of the brain reward system in cigarette craving in schizophrenia, and suggest that the neurophysiologic mechanisms involved in the regulation of cue-induced cigarette craving are impaired in this population.


Assuntos
Comportamento de Procura de Droga/fisiologia , Esquizofrenia/patologia , Psicologia do Esquizofrênico , Tabagismo/patologia , Tabagismo/psicologia , Adulto , Análise de Variância , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/fisiopatologia , Estatística como Assunto , Tabagismo/complicações , Tabagismo/diagnóstico por imagem , Adulto Jovem
11.
Psychiatry Res ; 214(1): 24-32, 2013 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-23906663

RESUMO

In schizophrenia cannabis abuse/dependence is associated with poor compliance and psychotic relapse. Despite this, the reasons for cannabis abuse remain elusive, but emotions may play a critical role in this comorbidity. Accordingly, we performed a functional magnetic resonance imaging study of emotional memory in schizophrenia patients with cannabis abuse (dual-diagnosis, DD). Participants comprised 14 DD patients, 14 non-abusing schizophrenia patients (SCZ), and 21 healthy controls (HC) who had to recognize positive and negative pictures while being scanned. Recognition of positive and negative emotions was prominently impaired in SCZ patients, relative to HC, while differences between DD and HC were smaller. For positive and negative stimuli, we observed significant activations in frontal, limbic, temporal and occipital regions in HC; in frontal, limbic and temporal regions in DD; and in temporal, parietal, limbic and occipital regions in the SCZ group. Our results suggest that emotional memory and prefrontal lobe functioning are preserved in DD relative to SCZ patients. These results are consistent with previous findings showing that cannabis abuse is associated with fewer negative symptoms and better cognitive functioning in schizophrenia. Longitudinal studies will need to determine whether the relative preservation of emotional memory is primary or secondary to cannabis abuse in schizophrenia.


Assuntos
Encéfalo/fisiopatologia , Emoções/fisiologia , Abuso de Maconha/psicologia , Memória/fisiologia , Esquizofrenia/fisiopatologia , Adolescente , Adulto , Mapeamento Encefálico , Diagnóstico Duplo (Psiquiatria) , Neuroimagem Funcional , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Abuso de Maconha/complicações , Abuso de Maconha/fisiopatologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Esquizofrenia/complicações , Psicologia do Esquizofrênico
12.
Schizophr Res Treatment ; 2013: 543842, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23970971

RESUMO

Growing evidence suggests that cannabis abuse/dependence is paradoxically associated with better cognition in schizophrenia. Accordingly, we performed a functional magnetic resonance imaging (fMRI) study of visuospatial abilities in 14 schizophrenia patients with cannabis abuse (DD), 14 nonabusing schizophrenia patients (SCZ), and 21 healthy controls (HCs). Participants performed a mental rotation task while being scanned. There were no significant differences in the number of mistakes between schizophrenia groups, and both made more mistakes on the mental rotation task than HC. Relative to HC, SCZ had increased activations in the left thalamus, while DD patients had increased activations in the right supramarginal gyrus. In both cases, hyper-activations are likely to reflect compensatory efforts. In addition, SCZ patients had decreased activations in the left superior parietal gyrus compared to both HC and DD patients. This latter result tentatively suggests that the neurophysiologic processes underlying visuospatial abilities are partially preserved in DD, relative to SCZ patients, consistently with the findings showing that cannabis abuse in schizophrenia is associated with better cognitive functioning. Further fMRI studies are required to examine the neural correlates of other cognitive dysfunctions in schizophrenia patients with and without comorbid cannabis use disorder.

13.
Cogn Neuropsychiatry ; 18(6): 615-30, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23343453

RESUMO

INTRODUCTION: Clozapine, the most widely used option in treatment-resistant schizophrenia, has been shown to be superior to other antipsychotic medications in improving cognitive function in patients. However, the results have not been consistent and the mechanisms underlying this effect have not been elucidated. Thus, the purpose of the present study was to evaluate verbal and nonverbal cognition (using visuospatial processing tests) in patients treated with clozapine (initially treatment resistant) and those treated with other second-generation antipsychotics, relative healthy control subjects. Furthermore, we examined neural correlates of visuospatial processing in the three groups. METHODS: Twenty schizophrenia patients treated with clozapine (TR-C group), 23 patients stabilised with atypical antipsychotics other than clozapine (NTR group), and 21 healthy control participants completed a battery of verbal and visuospatial cognitive tests. In addition, participants underwent functional magnetic resonance imaging (fMRI) while performing one of the visuospatial tests (the mental rotation task). The fMRI data were analysed separately in each group using Statistical Parametric Mapping software (SPM5). RESULTS: Overall, schizophrenia patients exhibited deficit on verbal and nonverbal processing relative to the healthy controls, but we observed some interesting differences between the two groups of patients. Specifically, the NTR group performed better than the TR-C group on the Block Design and the Raven's Progressive Matrices. With respect to brain function during mental rotation, the NTR group showed significant activations in regions of the temporal and occipital cortex, whereas the TR-C patients did not. The relative deactivations associated with the task were also more robust in NTR compared to the other group of patients, despite a similar performance. CONCLUSION: Present results suggest better visuospatial processing in the NTR relative to the TR-C group. This difference could be attributed to the treatment resistance itself or a lack of beneficial effect of clozapine relative to other atypical antipsychotics in ameliorating nonverbal abilities. Future studies of the relationship between clozapine and cognition, as well as between treatment resistance and cognition, are warranted.


Assuntos
Antipsicóticos/administração & dosagem , Clozapina/administração & dosagem , Transtornos Cognitivos/tratamento farmacológico , Cognição/efeitos dos fármacos , Esquizofrenia/tratamento farmacológico , Percepção Espacial/efeitos dos fármacos , Adolescente , Adulto , Benzodiazepinas/administração & dosagem , Dibenzotiazepinas/administração & dosagem , Resistência a Medicamentos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Olanzapina , Fumarato de Quetiapina , Risperidona/administração & dosagem , Esquizofrenia/fisiopatologia , Adulto Jovem
14.
Community Ment Health J ; 49(3): 317-22, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22847727

RESUMO

Community functioning is a broad term that encompasses various 'real world' measures of disability among schizophrenia patients. It includes outcomes such as independent living, social competence and behavioural problems-all of which are priorities for treatment among schizophrenia patients, mental health care providers, and family members. An important goal for rehabilitation programs is to identify predictors of community functioning which, in turn, could be used as targets for intervention. The present case-control study examined socio-demographic and substance use disorder (SUD) variables as well as psychiatric, extrapyramidal, and cognitive symptoms as predictors of community functioning in schizophrenia patients with (DD patients; n=31) and without comorbid SUDs (SCZ patients; n=31), and non-psychosis substance abusers (SUD patients; n=39). Psychiatric and extrapyramidal symptoms were evaluated with the Positive and Negative Syndrome Scale, the Calgary Depression Scale for Schizophrenia and the Extrapyramidal Symptoms Rating Scale. Cognition was evaluated using the Cambridge Neuropsychological Test Automated Battery (speed of processing, explicit and working memory). In SCZ patients, community functioning was predicted by explicit memory performance. In DD patients, community functioning was predicted by substance abuse, depression and speed of processing. In SUD patients, community functioning was predicted by substance abuse, positive symptoms and education. Our results suggest that cognition should be among the top treatment priorities in SCZ patients, whereas the key treatment targets in DD patients should be substance abuse and depression. Future studies will need to replicate the current findings, using prospective research designs.


Assuntos
Esquizofrenia , Ajustamento Social , Transtornos Relacionados ao Uso de Substâncias , Adolescente , Adulto , Canadá , Comorbidade , Depressão , Previsões , Humanos , Memória , Serviços de Saúde Mental , Pessoa de Meia-Idade , Esquizofrenia/reabilitação , Transtornos Relacionados ao Uso de Substâncias/reabilitação , Adulto Jovem
15.
Pain Med ; 13(12): 1571-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23170852

RESUMO

OBJECTIVE: Ever since the characterization of schizophrenia, clinicians have noted abnormal pain sensitivity in their patients. The published literature, however, is inconsistent concerning the nature of the change reported. The objective of this study was to characterize the pain response profile of schizophrenic patients by providing both acute and prolonged (i.e., rapidly repeating) painful stimuli to schizophrenic participants and control subjects. PARTICIPANTS: Twelve schizophrenic subjects and eleven controls were included in the final analysis. Diagnosis was made according to Diagnostic and Statistical Manual of mental disorders-4th edition, text revision (DSM-IV-TR) criteria. METHODS: Intermittent, transcutaneous stimulations of the left sural nerve were administered to all participants. Painful sural nerve stimulations provoked a nociceptive flexion reflex response which was measured using an electromyographic recording of the bicep femoris muscle. Pain ratings were obtained using a 0-10 verbal numerical scale. Among schizophrenic participants, the relationship between subjective pain, reflex amplitude, and clinical features was investigated. The Positive and Negative Syndrome Scale, Calgary Depression Scale for Schizophrenia, and Subjective Scale to Investigate Cognition in Schizophrenia were used to evaluate clinical features. RESULTS: Compared with controls, schizophrenic subjects showed increased sensitivity to acute pain (i.e., lower pain thresholds; P = 0.019), but decreased subjective pain sensitization (P = 0.027). Group differences in subjective pain sensitization were not accompanied by group differences in nociceptive reflex activity (P = 0.260), suggesting supraspinal origins to the change in pain experienced by schizophrenic subjects. Moreover, positive symptoms correlated negatively with pain threshold values among schizophrenic participants (r = -0.696, P = 0.012), suggesting that distortions of thought and function relate to pain sensitivity in schizophrenic patients. CONCLUSION: Results indicate that schizophrenic subjects present a specific experimental pain response profile, characterized by elevated sensitivity to acute pain but reduced sensitivity to prolonged pain.


Assuntos
Hiperalgesia/fisiopatologia , Percepção da Dor , Esquizofrenia Paranoide/fisiopatologia , Adulto , Estudos de Casos e Controles , Eletromiografia , Feminino , Humanos , Hiperalgesia/complicações , Masculino , Medição da Dor , Limiar da Dor , Transtornos Psicóticos/complicações , Transtornos Psicóticos/fisiopatologia , Reflexo , Esquizofrenia Paranoide/complicações , Nervo Sural , Estimulação Elétrica Nervosa Transcutânea
16.
Front Psychiatry ; 3: 85, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23055987

RESUMO

Schizophrenia is a complex psychiatric disorder strongly associated with substance use disorders. Theoretically, schizophrenia and SUD may share endocannabinoid alterations in the brain reward system. The main endocannabinoids, anandamide, and 2-arachidonoylglycerol, are lipids which bind cannabinoid receptors. Oleoylethanolamide (OEA), a fatty-acid ethanolamide, binds peroxisome proliferator-activated receptors. The endocannabinoid system has been shown to be impaired in schizophrenia, and recently, our group has shown that schizophrenia patients with SUD have elevated peripheral levels of anandamide and OEA that do not normalize after 3-month treatment with quetiapine. Objective For comparative purposes, we aimed to measure endocannabinoids in non-psychosis substance abusers and non-abusing schizophrenia patients. Methods Using liquid chromatography and mass spectrometry, we measured plasma levels of anandamide and OEA in non-psychosis SUD patients, non-abusing schizophrenia patients, and healthy controls. In an open-label manner, all patients received 12-week treatment with quetiapine. Results Anandamide and OEA were reduced in substance abusers without schizophrenia, relative to healthy controls (p < 0.05). Both endocannabinoids were unchanged in non-abusing schizophrenia patients. After quetiapine, anandamide, and OEA levels remained significantly reduced the SUD group (p < 0.05). Discussion Taken together with results of our previous study performed in dual-diagnosis patients, our results suggest that peripheral anandamide and OEA levels are impaired in patients with SUD in opposite ways according to the presence or absence of schizophrenia. Endocannabinoid alterations did not change with treatment, suggesting that they are trait markers. Further studies are necessary to understand the role of endocannabinoids in substance abusers with and without schizophrenia and to examine therapeutic implications.

17.
Psychiatry Res ; 200(2-3): 237-41, 2012 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-22980481

RESUMO

Substance use disorders (SUDs) are common in patients with schizophrenia and this comorbidity is associated with a poorer prognosis, relative to non-abusing patients. One hypothesis that has been advanced in the literature is that dual diagnosis (DD) patients may have a different personality profile than non-abusing schizophrenia patients. The present case-control study aimed to characterize levels of personality traits (sensation-seeking, social anhedonia, and impulsivity) in substance abuse/dependence patients with (DD group; n=31) and without schizophrenia (SUD group; n=39), relative to non-abusing schizophrenia patients (SCZ group; n=23), and healthy controls (n=25). Impulsivity was assessed using the Barratt Impulsivity Scale. Sensation-seeking was assessed using the Zuckerman Sensation Seeking Scale. Social anhedonia was assessed with the Chapman Social Anhedonia Scale. We found that sensation-seeking was significantly higher in DD and SUD, relative to SCZ patients. We found that social anhedonia was significantly elevated in DD and SCZ, relative to healthy controls. We found that impulsivity was significantly higher in DD, SCZ and SUD patients, compared to healthy controls. The results suggest that sensation-seeking is prominent in substance abuse/dependence (irrespective of schizophrenia), social anhedonia is prominent in schizophrenia (irrespective of substance abuse/dependence), and impulsivity is prominent in all three populations.


Assuntos
Anedonia , Comportamento Impulsivo/psicologia , Esquizofrenia/complicações , Psicologia do Esquizofrênico , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adulto , Diagnóstico Duplo (Psiquiatria) , Feminino , Humanos , Comportamento Impulsivo/complicações , Masculino , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Substâncias/complicações
18.
Schizophr Res Treatment ; 2012: 917901, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22966452

RESUMO

Schizophrenia has been associated with disturbed levels of sex-steroid hormones, including estrogen and testosterone. In the present study we have examined the implication of a less studied hormone progesterone. Forty-three patients with schizophrenia (21 women) and 43 control participants (21 women) underwent functional MRI while viewing emotionally positive, negative, and neutral images. Blood samples were taken prior to the scanning session to evaluate progesterone levels. Simple regression analyses between levels of progesterone and brain activations associated with emotion processing were performed using SPM5. A positive correlation was found between progesterone levels and brain activations during processing of emotionally charged images in both healthy and schizophrenia men, but no significant relationship was revealed in women. These preliminary results indicate that progesterone is significantly associated with brain activations during processing of positive and negative affect in healthy and schizophrenia men, but not in women. Further investigation is warranted.

19.
Prog Neuropsychopharmacol Biol Psychiatry ; 35(7): 1695-8, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21627977

RESUMO

BACKGROUND: Some but not all antipsychotics have been shown to modulate plasma cytokine levels in schizophrenia patients. Thus far, the most consistent finding has been the increase in plasma levels of soluble interleukin (IL)-2 receptor (sIL-2R) associated with clozapine treatment. Quetiapine is a second-generation antipsychotic with a pharmacological profile similar to that of clozapine, but its immunomodulatory effects have not been investigated in schizophrenia yet. The purpose of this exploratory study was to examine the changes in plasma levels of sIL-2R in schizophrenia during quetiapine treatment and association with psychopathology. METHODS: Participants were 29 schizophrenia-spectrum disorder patients (DSM-IV criteria), and 28 healthy controls. Patients had a comorbid substance use disorder (cannabis>alcohol>cocaine), since quetiapine is increasingly used in this population of dual diagnosis. No participant suffered from infection or overt inflammatory diseases. On baseline, patients taking mostly second-generation antipsychotics were switched to quetiapine for a 12-week open-label trial. Five patients were drop-outs. Mean dose of quetiapine for trial completers (n=24) was 466.6mg±227.3. Psychiatric variables were evaluated with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia. Plasma sIL-2R levels were assessed at baseline, weeks 6 and 12 in patients, and in healthy controls, using sandwich immunoassay. Plasma IL-6 and IL-1 receptor antagonist (IL-1RA) were measured for comparison purposes. RESULTS: On baseline, plasma sIL-2R, IL-6 and IL-1RA levels were higher in dual-diagnosis patients, compared to controls. Plasma sIL-2R further increased after quetiapine treatment (p=0.037), while plasma IL-6 and IL-1RA did not change. Clinical improvements were observed in positive, negative and depressive symptoms, and substance abuse severity (all p<0.01). Interestingly, changes in sIL-2R levels during treatment were inversely correlated with changes in positive symptoms (r=-0.524; p=0.009). That is, increases in sIL-2R levels were associated with reductions in positive symptoms. CONCLUSION: These data show that quetiapine elevates, like clozapine, sIL-2R levels in schizophrenia. Furthermore, the results suggest that sIL-2R alterations in schizophrenia rely on complex interplays between antipsychotics and the positive symptoms of the disorder. Future randomized controlled trials involving larger samples of schizophrenia patients are warranted to determine whether changes in plasma sIL-2R are quetiapine-related.


Assuntos
Antipsicóticos/farmacologia , Dibenzotiazepinas/farmacologia , Receptores de Interleucina-2/sangue , Esquizofrenia/tratamento farmacológico , Esquizofrenia/epidemiologia , Adulto , Sintomas Afetivos/diagnóstico , Sintomas Afetivos/fisiopatologia , Sintomas Afetivos/psicologia , Antipsicóticos/uso terapêutico , Comorbidade , Citocinas/sangue , Citocinas/imunologia , Dibenzotiazepinas/uso terapêutico , Feminino , Humanos , Interleucina-6/sangue , Interleucina-6/imunologia , Masculino , Escalas de Graduação Psiquiátrica , Fumarato de Quetiapina , Receptores de Interleucina-1/antagonistas & inibidores , Receptores de Interleucina-1/sangue , Receptores de Interleucina-1/imunologia , Receptores de Interleucina-2/imunologia , Esquizofrenia/diagnóstico , Esquizofrenia/imunologia , Transtornos Relacionados ao Uso de Substâncias/tratamento farmacológico , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/imunologia , Adulto Jovem
20.
Front Psychiatry ; 2: 22, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21629845

RESUMO

Neurological and psychiatric symptoms are consequences of substance abuse in schizophrenia and non-schizophrenia patients. The present case-control study examined changes in substance abuse/dependence, and neurological and psychiatric symptoms in substance abusers with [dual diagnosis (DD) group, n = 26] and without schizophrenia [substance use disorder (SUD) group, n = 24] and in non-abusing schizophrenia patients (SCZ group, n = 23) undergoing 12-week treatment with the atypical antipsychotic, quetiapine. Neurological and psychiatric symptoms were evaluated with the Positive and Negative Syndrome Scale, the Calgary Depression Scale for Schizophrenia, the Extrapyramidal Symptoms Rating Scale, and the Barnes Akathisia Rating Scale. At endpoint, DD and SCZ patients were receiving significantly higher doses of quetiapine (mean = 554 and 478 mg/day, respectively), relative to SUD patients (mean = 150 mg/day). We found that SUD patients showed greater improvement in weekly dollars spent on alcohol and drugs and SUD severity, compared to DD patients. At endpoint, there was no significant difference in dollars spent, but DD patients still had a higher mean SUD severity. Interestingly, DD patients had significantly higher parkinsonism and depression than SCZ patients at baseline and endpoint. On the other hand, we found that SUD patients had significantly more akathisia at baseline, improved more than SCZ patients, and this was related to cannabis abuse/dependence. Finally, SUD patients improved more in Positive and Negative Syndrome Scale positive scores than DD and SCZ patients. Taken together, our results provide evidence for increased vulnerability to the adverse effects of alcohol and drugs in schizophrenia patients. They also suggest that substance abuse/withdrawal may mimic some symptoms of schizophrenia. Future studies will need to determine the role quetiapine played in these improvements.

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