The interplay of psychotic and affective symptoms is a crucial challenge in understanding the pathogenesis of psychosis. In
this study, we analyzed the interplay between two subclinical psychosis symptoms dimensions, and one depression symptoms dimension,
using longitudinal data from Zurich. The Zurich study started in 1979 with a representative sample of 591 participants who
were aged 20/21. Follow-up interviews were conducted at age 23, 28, 30, 35, and 41. The psychiatric symptoms were assessed
with a semi-structured interview and the SCL 90-R. In this study, we analyzed three SCL-90-R subscales: the depression symptoms
dimension and two distinct symptoms dimensions of subclinical psychosis, one representing a schizophrenia nuclear symptom
dimension, the other representing a schizotypal symptoms dimension. Modeling was done with hybrid latent growth models, thereby
including simultaneous and cross-lagged effects. The interplay between the two subclinical psychosis symptoms dimensions and
the depression symptoms dimension includes several intertwined pathways. The schizotypal symptoms dimension has strong direct
effects on the schizophrenia nuclear symptoms dimension, but also on the depression symptoms dimension. The latter has for
its part an effect on the schizophrenia nuclear symptoms dimension. The main driving force within the dynamic interplay between
depression and psychosis symptoms is a schizotypal symptoms dimension, which represents social and interpersonal deficiencies,
ideas of reference, suspiciousness, paranoid ideation, and odd behavior. It does not only directly influence subclinical nuclear
schizophrenia symptoms but also the symptoms of depression.
Keywords Subclinical psychosis – Schizotypy – Schizotypal personality disorder – Depression – Community study – Epidemiological cohort