Several lines of evidence suggest that NMDA hypotheses have been implicated in schizophrenia. Previous studies found that some NMDA-enhancing agents were able to benefit the treatment of schizophrenia. Whether an NMDA-enhancer (NMDAE) can benefit the treatment of prodromal schizophrenia deserves study. Therefore, this study aims to compare NMDAE and placebo in the treatment of prodromal schizophrenia.~The subjects with prodromal schizophrenia at first receive 6 weeks of health-promotion intervention (including exercise and education). A total of 48 subjects who do not respond sufficiently to the health-promotion program are then recruited to this 12-week, randomized, double-blind, placebo-controlled trial, which aims to compare treatment response of NMDAE vs. placebo in 1:1 ratio. Clinical performances and side effects are measured at weeks -6 (before the screening phase), 0 (baseline of the drug trial), 2, 4, 6, 9, and 12. Cognitive functions are assessed at baseline and at endpoint of treatment by a battery of tests.~The efficacies of NMDAE and placebo will be compared. Chi-square (or Fisher's exact test) will be used to compare differences of categorical variables and t-test (or Mann-Whitney test if the distribution is not normal) for continuous variables between treatment groups. Mean changes from baseline in repeated-measure assessments will be assessed using the generalized estimating equation (GEE). All p values for clinical measures will be based on two-tailed tests with a significance level of 0.05.
Previous studies found that some NMDA-enhancing agents were able to improve clinical symptoms of patients with schizophrenia. Whether treatment of an NMDA-enhancing agent can benefit the treatment of prodromal schizophrenia deserves study.