The continuum hypothesis of psychosisschizotypy dimensions in nonclinical individuals: affective, psychopathological and functional correlates and measurement issues

Resumen

Aproximately 1% of the population suffers from schizophrenia, a mental disorder that results in devastating consequences for the person who struggles with it. During the last decades, research is showing that schizophrenia is part of a spectrum of aetiologically and phenomenologically related disorders that includes psychotic disorders like delusional disorder, for example, but also nonpsychotic disorders, as it is the case of schizotypal personality disorder, and, probably, schizotypy features as those measured in this thesis. These disorders tend to have their onset in late adolescence and early adulthood, causing a big disruption in the transition to adulthood with tremendous consequences devastating for independent living and functioning. Also, it has been suggested that schizophrenia spectrum disorders represent the most extreme manifestation of a continuum known as schizotypy. It is hypothesized that there is a continuum that ranges from minimal impairment to psychotic illnesses. Thus, schizotypy is a useful construct for studying the aetiology, development and expression of schizophrenia and related disorders, and ultimately, for the identification of individuals at risk for psychotic disorders or the development of preventive treatment interventions, independently of the effects that schizophrenic patients suffer (hospitalization, stigma, etc.). The studies presented in the present dissertation contribute to the research progress and understanding of the psychosis continuum by 1) providing reliable and word-wide used measures of schizotypy in Spanish language, 2) adding further evidence of the multidimensionality of the scales and the cross-cultural validity of this structure, and 3) showing that schizotypy dimensions have the same psychopathological and functional correlates (construct validity) and moderating factors in nonclinical individuals as presented by psychotic patients, a necessary condition to support the continuum hypothesis.