Schizoidia in schizophrenia spectrum and personality disorders: role of dissociation.

Dissociation was one of the roots of the nosopoetic construct "schizophrenia", and a link seems to exist between psychotic and dissociative phenomena. We explored the relationship between dissociation and schizoidia as defined by the Dissociative Experiences Scale (DES) total score and the schizoidia subscale of the Munich Personality Test (MPT), respectively. The study comprised 43 outpatients diagnosed with schizophrenia spectrum disorders in remission, 47 outpatients with personality disorders and 42 non-patients. Besides the DES and the MPT, all participants also completed parts of the Symptom Checklist (SCL-90-R) and theTrauma Questionnaire (TQ). In the final multivariable logistic model, a set of five variables was identified as the strongest contributors to the occurrence of schizoida. The model included TQ broken home, MPT neuroticism, schizophrenia spectrum and personality disorder diagnoses, and SCL aggressivity; it did not include any dissociation variable. The purported relationship between dissociation and schizoidia could not be confirmed; the existence of schizophrenia-inherent dissociation appears questionable.