A longitudinal mediation analysis of the effect of negative-self-schemas on positive symptoms via negative affect

Background. Cognitive models postulate that negative-self-schemas (NSS) cause and maintain positive symptoms and that negative affect mediates this link. However, only few studies have tested the temporal mediation claim systematically using an appropriate design. Methods. A longitudinal cohort design in an online community sample (N=962) from Germany, Indonesia, and the USA was used. NSS, negative affect and positive symptoms were measured at four time-points (T0-T3) over a 1-year period. Cross-lagged panel and longitudinal mediation analyses with structural equation modeling were used to test the temporal mediation. Results. Independent cross-lagged panel models showed a significant unidirectional longitudinal path from NSS to positive symptoms (T2-T3, beta= 0.18, p < 0.01) and bidirectional longitudinal associations from NSS to negative affect (T0-T1, gamma= 0.14, p <0.01) and vice versa (T0-T1, gamma= 0.19, p < 0.01). There was also a significant indirect pathway from NSS at baseline via negative affect at T1 and T2 to positive symptoms at T3 (unstandardized indirect effect coefficient = 0.020, p < 0.05, BCa CI 0.004-0.035), indicating mediation. Conclusions. Our findings support the postulated affective pathway from NSS to positive symptoms via negative affect. Specifically, our data indicate that NSS and negative affect influence each other and build up over the course of several months before leading on to positive symptoms. We conclude that interrupting this process by targeting NSS and negative affect early in the process could be a promising strategy to prevent the exacerbation of positive symptoms.