Figure 2. Flow chart of clinical procedures. Patients with chronic SCZ were blind-randomized to a group I (n=8) or group II (n=7) to receive four infusions of placebo (in blue) or sNP (in red), respectively, in phase A of treatment. In the second phase (phase B), those receiving four infusions of PLACEBO in phase A were switched to sNP, while the group receiving sNP in phase A was switched to placebo in phase B of treatment. Blood was collected before (at baseline) and 4 h after each infusion of placebo or sNP. Clinical assessments occurred hourly during the 4-h infusion (i.e., total of four assessments for each patient per infusion). The interval between each infusion was of 1 month (i.e., 4 weeks each). BPRS = Brief Psychiatric Rating Scale; Ndel1 = nuclear distribution element-like 1; PANSS = Positive and Negative Syndrome Scale; SCZ = schizophrenia; sNP = sodium nitroprusside.