RESUMO
OBJECTIVE: To investigate the influence of brain-derived neurotrophic factor (BDNF) gene variations on cognitive performance and clinical symptomatology in first-episode psychosis (FEP). METHODS: We performed BDNF val66met variant genotyping, cognitive testing (verbal fluency and digit spans) and assessments of symptom severity (as assessed with the PANSS) in a population-based sample of FEP patients (77 with schizophreniform psychosis and 53 with affective psychoses) and 191 neighboring healthy controls. RESULTS: There was no difference in the proportion of Met allele carriers between FEP patients and controls, and no significant influence of BDNF genotype on cognitive test scores in either of the psychosis groups. A decreased severity of negative symptoms was found in FEP subjects that carried a Met allele, and this finding reached significance for the subgroup with affective psychoses (p < 0.01, ANOVA). CONCLUSIONS: These results suggest that, in FEP, the BDNF gene Val66Met polymorphism does not exert a pervasive influence on cognitive functioning but may modulate the severity of negative symptoms.
OBJETIVO: Investigar a influência da variação do gene do fator neurotrófico derivado do cérebro (BDNF) no desempenho cognitivo e na sintomatologia clínica durante o primeiro episódio psicótico (PEP). MÉTODOS: Foram realizados a genotipificação das variantes Val66met do BDNF, o teste cognitivo (fluência verbal e repetição de dígitos) e as avaliações da gravidade dos sintomas (conforme avaliado pela Positive and Negative Syndrome Scale [PANSS]) em uma amostra de pacientes com PEP de base populacional (77 com psicose esquizofreniforme e 53 com psicose afetiva) e 191 vizinhos controle saudáveis. RESULTADOS: Não houve diferença na proporção de portadores do alelo Met entre pacientes com PEP e o grupo controle. Não houve influência significativa do genótipo do BDNF sobre a pontuação de cada um dos grupos psicóticos. Foi encontrada uma diminuição da gravidade dos sintomas negativos em sujeitos com PEP portadores do alelo Met, e essa descoberta mostrou-se significativa para o subgrupo com psicose afetiva (p < 0,01, ANOVA). CONCLUSÕES: Os resultados sugerem que, no PEP, o polimorfismo Val66Met do gene do BDNF não exerce uma influência importante sobre o funcionamento cognitivo, mas pode modular a gravidade dos sintomas negativos.
Assuntos
Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Fator Neurotrófico Derivado do Encéfalo/genética , Cognição/fisiologia , Polimorfismo de Nucleotídeo Único/genética , Transtornos Psicóticos/genética , Brasil , Genótipo , Índice de Gravidade de DoençaRESUMO
OBJECTIVE: To investigate the influence of brain-derived neurotrophic factor (BDNF) gene variations on cognitive performance and clinical symptomatology in first-episode psychosis (FEP). METHODS: We performed BDNF val66met variant genotyping, cognitive testing (verbal fluency and digit spans) and assessments of symptom severity (as assessed with the PANSS) in a population-based sample of FEP patients (77 with schizophreniform psychosis and 53 with affective psychoses) and 191 neighboring healthy controls. RESULTS: There was no difference in the proportion of Met allele carriers between FEP patients and controls, and no significant influence of BDNF genotype on cognitive test scores in either of the psychosis groups. A decreased severity of negative symptoms was found in FEP subjects that carried a Met allele, and this finding reached significance for the subgroup with affective psychoses (p < 0.01, ANOVA). CONCLUSIONS: These results suggest that, in FEP, the BDNF gene Val66Met polymorphism does not exert a pervasive influence on cognitive functioning but may modulate the severity of negative symptoms.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Cognição/fisiologia , Polimorfismo de Nucleotídeo Único/genética , Transtornos Psicóticos/genética , Adolescente , Adulto , Brasil , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Adulto JovemRESUMO
The present study aimed to investigate the presence of corpus callosum (CC) volume deficits in a population-based recent-onset psychosis (ROP) sample, and whether CC volume relates to interhemispheric communication deficits. For this purpose, we used voxel-based morphometry comparisons of magnetic resonance imaging data between ROP (n =122) and healthy control (n = 94) subjects. Subgroups (38 ROP and 39 controls) were investigated for correlations between CC volumes and performance on the Crossed Finger Localization Test (CFLT). Significant CC volume reductions in ROP subjects versus controls emerged after excluding substance misuse and non-right-handedness. CC reductions retained significance in the schizophrenia subgroup but not in affective psychoses subjects. There were significant positive correlations between CC volumes and CFLT scores in ROP subjects, specifically in subtasks involving interhemispheric communication. From these results, we can conclude that CC volume reductions are present in association with ROP. The relationship between such deficits and CFLT performance suggests that interhemispheric communication impairments are directly linked to CC abnormalities in ROP.
Assuntos
Transtornos Cognitivos/etiologia , Corpo Caloso/patologia , Lateralidade Funcional/fisiologia , Transtornos Psicóticos/complicações , Transtornos Psicóticos/patologia , Transferência de Experiência/fisiologia , Adolescente , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estatística como Assunto , Adulto JovemRESUMO
BACKGROUND: Neuropsychological deficits have been reported in association with first-episode psychosis (FEP). Reductions in grey matter (GM) volumes have been documented in FEP subjects compared to healthy controls. However, the possible inter-relationship between the findings of those two lines of research has been scarcely investigated. OBJECTIVE: To investigate the relationship between neuropsychological deficits and GM volume abnormalities in a population-based sample of FEP patients compared to healthy controls from the same geographical area. METHODS: FEP patients (n=88) and control subjects (n=86) were evaluated by neuropsychological assessment (Controlled Oral Word Association Test, forward and backward digit span tests) and magnetic resonance imaging using voxel-based morphometry. RESULTS: Single-group analyses showed that prefrontal and temporo-parietal GM volumes correlated significantly (p<0.05, corrected) with cognitive performance in FEP patients. A similar pattern of direct correlations between neocortical GM volumes and cognitive impairment was seen in the schizophrenia subgroup (n=48). In the control group, cognitive performance was directly correlated with GM volume in the right dorsal anterior cingulate cortex and inversely correlated with parahippocampal gyral volumes bilaterally. Interaction analyses with "group status" as a predictor variable showed significantly greater positive correlation within the left inferior prefrontal cortex (BA46) in the FEP group relative to controls, and significantly greater negative correlation within the left parahippocampal gyrus in the control group relative to FEP patients. CONCLUSION: Our results indicate that cognitive deficits are directly related to brain volume abnormalities in frontal and temporo-parietal cortices in FEP subjects, most specifically in inferior portions of the dorsolateral prefrontal cortex.