The effectiveness of interventions for internalizing disorders in children and adolescents was studied using a review and meta-analysis of published single-case research. Databases and other resources were searched for quantitative single-case studies in youth with anxiety, depressive, and posttraumatic stress disorders. Raw data from individual cases were aggregated and analyzed by means of multilevel meta-analytic models. Outcome variables were symptom severity assessed across baseline and treatment phases of the studies, and diagnostic status at post- and follow-up treatment. Single-case studies were rated for quality. We identified 71 studies including 321 cases (M^age = 10.66 years; 55% female). The mean quality of the studies was rated as below average, although there were considerable differences between the studies. Overall, positive within-person changes during the treatment phase in comparison to the baseline phase were found. In addition, positive changes in the diagnostic status were observed at post- and follow-up treatment. Yet high variability in treatment effects was found between cases and studies. This meta-analysis harvests the knowledge from published single-case research in youth-internalizing disorders and illustrates how within-person information from single-case studies can be summarized to explore the generalizability of the results from this type of research. The results emphasize the importance of keeping account of individual variability in providing and investigating youth interventions.

通过对已发表的单例研究的回顾和荟萃分析，研究了儿童和青少年内化障碍干预措施的有效性。在数据库和其他资源中搜索了针对患有焦虑、抑郁和创伤后应激障碍的青少年的定量单例研究。通过多层次荟萃分析模型对个案的原始数据进行汇总和分析。结果变量是在研究的基线和治疗阶段评估的症状严重程度，以及治疗后和后续治疗的诊断状态。对单案例研究进行质量评级。我们确定了 71 项研究，包括 321 例病例（男性^年龄 = 10.66 岁；55% 为女性）。尽管研究之间存在相当大的差异，但研究的平均质量被评为低于平均水平。总体而言，与基线阶段相比，治疗阶段的人体内发生了积极的变化。此外，在治疗后和后续治疗中观察到诊断状态的积极变化。然而，病例和研究之间的治疗效果存在很大差异。这项荟萃分析收集了已发表的青少年内化障碍单例研究的知识，并说明了如何总结单例研究的个人信息，以探索此类研究结果的普遍性。结果强调了在提供和调查青年干预措施时考虑个体差异的重要性。