RESUMEN
BACKGROUND: Semantic network abnormalities in patients with psychotic disorder were examined using associative prime-target relations with two stimulus asynchronies (SOAs; -250ms and -500ms) to assess the time course of automatic and more controlled processes of semantic priming. To investigate whether an aberrant semantic network system is part of the familial liability for psychosis, healthy siblings of patients with psychotic disorder were additionally examined. The N400 event-related brain potential (ERP) was used as a probe of semantic processing. METHOD: Twenty-two patients with psychotic disorder, twenty siblings of patients with psychotic disorder and twenty controls participated in a lexical decision task and ERPs were recorded to target words that were associatively, indirectly or not related to their preceding prime word. RESULTS: Associative priming of the N400 amplitude was found across all participants and both SOAs, but no between-group differences were found for the N400 amplitude (both SOAs). The Group×Condition interaction of the indirect priming N400 latency of the three groups was just short of statistical significance (F2,59=2.7, p=.077). Patients showed an increased indirect priming effect of the N400 latency only at short SOA, with decreased latency of the indirectly related compared to the unrelated condition, while controls did not show an indirect priming N400 latency effect. No between-group differences in N400 latency of indirect priming were found at the long SOA. Only a trend towards a Group×Condition interaction of the indirect priming N400 latency between the sibling and the controls was found, but without a main effect of indirect priming in the sibling group. CONCLUSION: These preliminary results support the assumption of a hyperactive semantic network in patients with psychotic disorder, which develops under automatic processes and decreases with more controlled processes, but does not represent clear trait familial liability.
Asunto(s)
Depresión de Propagación Cortical/fisiología , Toma de Decisiones/fisiología , Potenciales Evocados/fisiología , Familia , Desempeño Psicomotor/fisiología , Trastornos Psicóticos/fisiopatología , Adolescente , Adulto , Electroencefalografía/métodos , Familia/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa/métodos , Trastornos Psicóticos/genética , Trastornos Psicóticos/psicología , Tiempo de Reacción/fisiología , Adulto JovenRESUMEN
OBJECTIVE: The associations of two types of childhood trauma (abuse and neglect) with psychosis symptom domains were investigated in subjects with psychotic illness, high psychosis vulnerability, and average psychosis vulnerability. METHOD: Childhood trauma was assessed with the Childhood Trauma Questionnaire. Symptoms were assessed with the Positive and Negative Syndrome Scale in the patients (N=272) and with the Structured Interview for Schizotypy-Revised in the patients' siblings (N=258), and healthy comparison subjects (N=227). RESULTS: Childhood trauma was associated with psychotic disorder in a dose-response fashion in the comparison of patients and healthy subjects (adjusted odds ratio=4.53, 95% CI=2.79-7.35). The comparison of siblings and healthy subjects suggested that siblings shared a degree of trauma with the patients (adjusted odds ratio=1.61, 95% CI=0.95-2.61), but the patient-sibling comparison indicated much greater exposure in patients than in siblings (adjusted odds ratio=2.60, 95% CI=1.78-3.78). Childhood abuse but not neglect was associated with positive but not negative symptoms in a dose-response fashion in all three groups. There was no evidence for moderation by sex. CONCLUSIONS: Discordance in psychotic illness across related individuals can be traced to differential exposure to trauma. The association between trauma and psychosis is apparent across different levels of illness and vulnerability to psychotic disorder, suggesting true association rather than reporting bias, reverse causality, or passive gene-environment correlation. Positive psychotic symptoms in vulnerable individuals may arise as a consequence of the level and frequency of exposure to abuse rather than neglect, suggesting symptom-specific and exposure-specific underlying mechanisms.
Asunto(s)
Maltrato a los Niños/psicología , Trastornos Psicóticos/etiología , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos Psicóticos/diagnóstico , Hermanos , Encuestas y CuestionariosRESUMEN
OBJECTIVE: Abnormalities of the auditory P300 are a robust finding in patients with psychosis. The purposes of this study were to determine whether patients with a psychotic disorder and their unaffected siblings show abnormalities in P300 and N100 and to establish test-retest reliabilities for these ERP components. METHODS: Using an auditory oddball paradigm, P300 and N100 latency and amplitude were acquired from 19 patients with a psychotic disorder, 28 unaffected siblings, and 37 healthy controls, on two separate occasions. ERP components were compared between groups, using multilevel random regression analyses. Intraclass correlations were used to determine consistency of ERP components between the sessions. RESULTS: A delayed target N100 latency was found in unaffected siblings. Patients showed significantly delayed P300 latency and diminished P300 amplitude compared to controls. Most ERP parameters showed good test-retest reliability. However, patients did not show sufficient reliability for N100 latency for standard stimuli. CONCLUSIONS: The present study failed to find significant P300 abnormalities in unaffected siblings. However, N100 latency is delayed in siblings and can be reliably measured in all groups for target stimuli, suggesting that this component, rather than P300, may serve as liability marker. SIGNIFICANCE: N100 latency is a promising biomarker for psychosis liability.
Asunto(s)
Potenciales Relacionados con Evento P300/genética , Potenciales Evocados Auditivos/genética , Fenotipo , Trastornos Psicóticos/genética , Trastornos Psicóticos/fisiopatología , Hermanos , Estimulación Acústica/métodos , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos Psicóticos/psicología , Reproducibilidad de los Resultados , Hermanos/psicología , Adulto JovenRESUMEN
OBJECTIVE: The aim of this study was to examine whether proneness to subjective cognitive failure (cognitive based mistakes) increases the risk for the development of symptoms of psychosis and to what degree any association was familial. METHODS: At baseline, the Cognitive Failure Questionnaire (CFQ) and the Community Assessment of Psychic Experiences (CAPE) questionnaire were administered in a general population sample of genetically related individuals (n = 755). Individuals scoring high (>75th percentile) or average on the CAPE (between 40th and 60th percentile) (n = 488) were reinterviewed with the CAPE and Structured Interview for Schizotypy-Revised (SIS-R) at follow-up (mean interval = 7.7 months, SD = 4.8 months). RESULTS: Cross-trait, within-relative analysis showed a significant association between the CFQ and the negative dimension, assessed with both the CAPE and SIS-R, whereas no association was found between the CFQ and the positive dimension. Cross-trait, between-relative analyses showed no association between the CFQ in one relative and any of the dimensions of the subclinical psychosis phenotype in the other relative. CONCLUSION: Proneness to subjective cognitive failure possibly contributes to the development or persistence of negative symptoms and can be seen as potential risk factor for negative symptoms of psychosis. This overlap is due to individual effects rather than familial liability.