Flowchart of the trial.
Eligible participants were screened and randomized to receive antipsychotics plus metformin or antipsychotics alone for 24 weeks. MRI and cognitive testing were conducted at baseline, after 12 weeks of treatment, and at the end of the trial at week 24.We then performed mediation analyses to evaluate the relationship among metformin treatment, MCCB scores, and FC changes using BruceR packages (R version 4.2.0, 