Developmental trajectories of schizotypal personality disorder-like behavioural manifestations: a two-year longitudinal prospective study of college students

Background: Previous evidence has shown that schizotypal personality disorder (SPD)is part of the schizophrenia spectrum. Few studies have examined latent classes in the developmental trajectories of SPD features over time in individuals with SPD features. Methods: We adopted a longitudinal prospective study design to follow up a cohort of 660 college students during a two-year period. Participants' SPD-like symptoms and psychosocial function were measured by a comprehensive set of questionnaires that covered SPD features and cognitive, emotional, and psychosocial functions. Latent class growth analysis was used to examine the trajectory classes. Results: Three trajectory classes were identified: a low, a medium, and a high SPD features group. Participants in the low group reported few SPD features and their symptoms declined over time. The medium group students had more SPD features than the low group and these symptoms stabilized during the follow up period. Participants in the high group reported the most SPD features and their symptoms increased over time. The three groups differed in paranoid thoughts, psychological distress, neurocognition function, and emotional expression over time. Results of multivariate regression analysis suggested that paranoid thoughts, emotional experience and prospective memory were predictors of social functioning in the high SPD feature group. Conclusions: Our findings suggest that individuals with SPD features may be delineated into different developmental subgroups and these subgroups differ significantly in psychosocial function. Delusions, emotion, and prospective memory may be important features to consider in early diagnosis and interventions for individuals predisposed to SPD and schizophrenia.