d-Cycloserine is a partial agonist at the glycine site of the N-methyl-D-aspartate (NMDA) receptor. Results have been inconsistent in trials on the efficacy of d-Cycloserine in patients with schizophrenia. We examined the efficacy of d-Cycloserine against negative and cognitive symptoms (primary and co-primary outcomes). Secondary outcomes were efficacy of d-Cycloserine against positive symptoms and the examination of early treatment outcomes. A systematic literature search was carried out using following selection criteria: Population = Patients with Schizophrenia; Intervention = Trials using d-Cycloserine either as monotherapy or adjuvant therapy; Comparison = Placebo or active comparator; Outcome = Change in negative symptoms, cognitive symptoms and positive symptoms; Study design = Randomized controlled trials with parallel design. We used the Cochrane Collaboration tool for risk of bias for study quality appraisal. Effect sizes for trials were calculated separately for negative, positive and cognitive symptom dimensions using the DerSimonian–Laird random effects model. Seven studies (pooled N = 413) provided data for meta-analysis. The pooled Standardized Mean Difference (SMD) for negative, cognitive, and positive symptom change scores were − 0.32 (95% CI, − 0.75 to 0.11), − 0.05 (95% CI, − 0.91 to 0.81), and − 0.08 (95% CI, − 0.37 to 0.20), respectively. No significant improvement was noted with regard to early outcome. I² values for heterogeneity were 61%, 67%, and 0% for studies assessing negative, cognitive, and positive symptom ratings, respectively. d-Cycloserine did not exhibit significant efficacy in treating negative, cognitive, or positive symptoms of schizophrenia at either study-defined endpoint (4–36 weeks) or at four weeks (early outcome).

d-环丝氨酸是 N-甲基-D-天冬氨酸 (NMDA) 受体甘氨酸位点的部分激动剂。d-环丝氨酸对精神分裂症患者疗效的试验结果不一致。我们检查了d-环丝氨酸对阴性和认知症状（主要和共同主要结果）的功效。次要结果是d-环丝氨酸对阳性症状的疗效和早期治疗结果的检查。使用以下选择标准进行了系统的文献检索： 人口 = 精神分裂症患者；干预 = 使用d 的试验-环丝氨酸作为单一疗法或辅助疗法；比较 = 安慰剂或主动比较器；结果 = 阴性症状、认知症状和阳性症状的变化；研究设计 = 平行设计的随机对照试验。我们使用 Cochrane 协作工具来评估研究质量评估的偏倚风险。使用 DerSimonian-Laird 随机效应模型，针对消极、积极和认知症状维度分别计算试验的效应量。七项研究（汇集N = 413) 为荟萃分析提供了数据。阴性、认知和阳性症状变化评分的合并标准化平均差异 (SMD) 为 − 0.32（95% CI，− 0.75 至 0.11）、− 0.05（95% CI，− 0.91 至 0.81）和 − 0.08（95 % CI, − 0.37 至 0.20)，分别。在早期结果方面没有注意到显着改善。对于评估阴性、认知和阳性症状评级的研究，异质性的I ²值分别为 61%、67% 和 0%。在研究定义的终点（4-36 周）或 4 周（早期结果），d-环丝氨酸在治疗精神分裂症的阴性、认知或阳性症状方面没有表现出显着疗效。