Table 6.

Fit indices obtained in the CFAs using the PANSS 2-factor negative symptom solutions previously identified in schizophrenia research by Jang et al. (2016) and by Pelizza et al. (2020) within our FEP patients with affective psychosis (n =78).

Fit indices (Jang’s model)	2-factor negative symptom model	Accepted values
Χ2 CFI TLI RMSEA SRMR	106.939 (p = 0.000) 0.867 0.785 0.317 0.198	p > 0.05 ≥ 0.90 ≥ 0.90 ≤ 0.08 ≤ 0.08
Fit indices (Pelizza’s model) (baseline [T0])	2-factor negative symptom model	Accepted values
Χ2 CFI TLI RMSEA SRMR	18.611 (p = 0.136) 0.992 0.987 0.077 0.066	p > 0.05 ≥ 0.90 ≥ 0.90 ≤ 0.08 ≤ 0.08
Fit indices (Pelizza’s model) (1-year follow-up assesment time [T1])	2-factor negative symptom model	Accepted values
Χ2 CFI TLI RMSEA SRMR	24.435 (p = 0.027) 0.994 0.990 0.121 0.076	p > 0.05 ≥ 0.90 ≥ 0.90 ≤ 0.08 ≤ 0.08

Legend – CFA = Confirmatory Factor Analysis; PANSS = Positive And Negative Syndrome Scale; FEP = First Episode Psychosis; X2 = Chi-square value; p = statistical value; CFI = Comparative Fit Index; TLI = Tucker-Lewis Index; RMSEA = Root Mean Square Error of Approximation; SRMR = Standardized Root Mean Square Residual.