Exploring delusional themes and other symptoms in first episode psychosis: A network analysis over two timepoints.

Delusions are a defining feature of psychosis and play an important role in the conceptualization and diagnosis of psychotic disorders; however, the particular role that different delusions play in the prognosis of these disorders is not well understood. This study explored relationships between delusions and other symptoms in 674 first episode psychosis (FEP) individuals by comparing symptom networks between baseline and 12 months after intake to an early intervention service. Specifically, we (1) estimated regularized partial correlation networks at baseline and month 12, (2) identified the most central symptoms in each network, (3) identified clusters of highly connected symptoms, and (4) compared networks to examine changes in structure and connectivity. At baseline, the most central symptoms were depression, delusions of mind reading, and delusions of thought insertion. At month 12, they were hallucinations, persecutory delusions, and delusions of thought insertion. A symptom cluster was identified at both timepoints comprising of five delusions corresponding to passivity experiences. While network structures did not differ significantly, the month 12 network was significantly more highly connected. Our study captures a shift in illness trajectory over time, wherein transdiagnostic symptomatology at baseline becomes more consolidated around psychotic symptoms by month 12.