Factor and network analysis of psychosis-like experiences and depressive symptoms in a sample of Finnish adolescents entering psychiatric services.

Abstract

Psychosis-Like Experiences (PLEs) and depressive symptoms are correlated in clinical adolescent populations. However, symptom-level associations between the two phenomena are not clear. We analysed factor structures of a PLE instrument, the Prodromal Questionnaire-Brief (PQ-B), based on dimensions of positive symptoms of schizophrenia, and a depression measurement instrument, the Beck Depression Inventory (BDI-21A) and performed a network analysis of item-level associations between the two measures. The sample consisted of 417 adolescents (range 13-18 years of age, mean 14.9 years, 72.4% females) entering secondary psychiatric services at Helsinki metropolitan area, Finland. Confirmatory factor analysis resulted in adequately fitting 2-factor solution, one for PQ-B and one for BDI-21, with a strong correlation coefficient of 0.605 between the two factors. In the network analysis, PQ-B and BDI-21 both formed their own clusters, and two significant pathways were estimated between PQ-B and BDI-21 clusters: 1. the association between paranoid thinking and distorted body image, and 2. the association between somatic preoccupation and worry about problems of one's mind. Even though on a general, factor level, PLEs and depressive symptoms were strongly correlated, unique associations between symptoms of the two constructs were sparse. These findings should be considered in the psychiatric assessment and in the care of adolescents.