La vulnerabilitat a desenvolupar psicosi vista des del Trastorn Esquizotípic de la Personalitat: Estudi del continuum entre salut i esquizofrènia

Abstract

The Schizotypal Personality Disorder (SPD) research provides data for a better understanding of schizophrenia, as it allows to study the psychopathological bases that share both disorders without confusing factors such as pharmacological treatment, institutionalization and chronicity of the illness. Due to the fact that the clinical deterioration of the disease starts before the emergence of psychotic symptoms, the strategies to modify the schizophrenia course focused on the identification of risk factors and prodromal symptoms that allows an early intervention. The objective of this thesis is to deepen in the detection of vulnerability markers to develop schizophrenia. First of all, the Schizotypal Personality Questionnaire (SPQ) has been validated to detect early-stage schizotyal features in the population, and secondly, ERN biomarker has been studied to detect deficits in behavioral monitoring and its reversibility with the dopaminergic antagonist drug risperidone. The results show, on the one hand, good psychometric properties for the SPQ (Cronbach’s alpha = 0.90 (0.57-0.83)), and the factorial model that best fits the construct is the 4-factor paranoid, which differentiates the following factors: Cognitive-Perceptive, Negative, Disorganized, and Paranoid. On the other hand, people with TEP showed a decrease in ERN wave compared to the control group and also a worse performance in a time of reaction with choice (Eriksen Flanker Task). These behavior monitoring deficits were subsequently reversed with the administration of risperidone in the TEP group. Paradoxically, the control group performance worsened with the administration of risperidone. This is due to the fact that dopamine regulates cognitive functions following an inverted-U model, in which the effects of dopaminergic drugs depend on the basal performance levels. Thus, whereas in healthy volunteers the drug administration displaces the performance to the left of the optimum point by worsening it, the reduction of the dopaminergic hyper activation in schizotypy improves the monitoring of the behavior.

Date of Award	11 Oct 2018
Original language	Catalan
Supervisor	Iluminada Corripio Collado (Director) & Jordi Riba Serrano (Director)