The Role of Negative Symptoms on the Continuum of Psychosis Risk as a Mediator of the Relationship Between Personality and Functioning in Individuals With Psychotic-Like Experiences

Aim Psychotic-like experiences (PLEs) may increase the risk of psychosis. Most of the research on PLEs focuses on their positive dimension-for example, hallucinatory-like experiences or delusion-like thoughts. Relatively little is known about the role of PLEs on the continuum of negative symptoms. The aim of this study was to examine whether negative symptoms, both in the experiential and expressive dimensions, could mediate the effects of temperament and character on the level of functioning of individuals with PLEs. Methods The study was conducted on 107 healthy young adults with the highest severity of PLEs, selected from a larger sample of 6722 people recruited for another study. Participants were examined using the Cloninger Temperament and Character Inventory, the Brief Negative Symptom Rating Scale, and the Social and Occupational Functioning Assessment Scale. Results Both functioning and certain personality traits, such as harm avoidance, persistence, self-directedness, and cooperativeness, were more strongly associated with the occurrence of experiential rather than expressive negative symptoms. We have developed four models, in which we have shown that the experiential negative symptoms mediated the impact of the temperament and character traits on socio-occupational functioning. In each model, negative symptoms weakened the direct effect of the personality trait on functioning. Conclusions These findings suggest that, like at the other stages of psychosis risk, a constellation of specific temperament and character traits is a risk factor for functional decline, which may be partly explained by the effect of experiential negative symptoms. The study also confirms the different impact of the two domains of negative symptoms on functional outcomes, suggesting the need for developing targeted interventions.