Supplementary Material for: Polarity Index of Psychological Interventions in Maintenance Treatment of Bipolar Disorder

<b><i>Background:</i></b> Although several adjunctive psychological interventions are effective in the maintenance of bipolar disorders (BD), no attempt has been made to classify them according to their ability to prevent manic versus depressive episodes. Our study aims to rank the adjunctive psychotherapies for the prophylaxis of BD by means of their polarity index (PI). <b><i>Methods:</i></b> Randomized controlled trials comparing the efficacy of a psychological intervention with a comparator in BD maintenance treatment in patients aged over 18 were systematically reviewed. Exclusion criteria were a small sample size, a study sample not exclusively composed of bipolar patients and the absence of a control group. PI is a novel metric indicating the relative antimanic versus antidepressive preventive efficacy of treatments. PI was retrieved by calculating the ratio of the number needed to treat (NNT) for prevention of depression and the NNT for prevention of mania. PI &gt;1.0 indicates a relatively higher antimanic prophylactic efficacy and PI &lt;1.0 a greater antidepressive efficacy. <b><i>Results:</i></b> A total of 9 studies were included. PI was 0.33, 0.63 and 0.89 for cognitive-behavioral therapy, 0.42 for family-focused therapy, 0.73 and 0.78 for psychoeducation, 1 for enhanced relapse prevention, 1.78 for caregiver group psychoeducation and 3.36 for brief technique-driven interventions. With regard to the PI for 1 cognitive-behavioral study, enhanced relapse prevention and brief technique-driven interventions may not be reliable since those trials were negative. <b><i>Conclusions:</i></b> The PI provides a measure of how much depression-preventive or (hypo) mania-preventive an intervention is and may guide the choice of adjunctive psychotherapy in the context of individualized long-term treatment of BD.

**背景**：尽管已有多种辅助心理干预措施可有效应用于双相情感障碍（bipolar disorders, BD）的维持治疗，但目前尚无研究依据其预防躁狂发作与抑郁发作的能力对这类干预措施进行分类。本研究旨在通过极性指数（polarity index, PI）对用于双相情感障碍维持治疗的辅助心理疗法进行排序。
**方法**：我们对18岁以上双相情感障碍患者中，比较心理干预与对照措施用于维持治疗疗效的随机对照试验开展系统综述。本研究的排除标准包括：样本量过小、研究样本未仅包含双相情感障碍患者，以及未设置对照组。极性指数（PI）是一项新型评价指标，用于反映治疗措施相对的抗躁狂与抗抑郁预防效能。PI通过计算预防抑郁所需的需治疗人数（number needed to treat, NNT）与预防躁狂所需的需治疗人数（NNT）的比值得到。当PI>1.0时，提示该干预措施的抗躁狂预防效能相对更高；当PI<1.0时，则提示其抗抑郁预防效能更强。
**结果**：本研究共纳入9项相关研究。认知行为疗法（cognitive-behavioral therapy）的PI分别为0.33、0.63和0.89；家庭聚焦疗法（family-focused therapy）的PI为0.42；心理教育（psychoeducation）的PI为0.73和0.78；强化复发预防疗法（enhanced relapse prevention）的PI为1.0；照料者团体心理教育（caregiver group psychoeducation）的PI为1.78；简短技术导向干预（brief technique-driven interventions）的PI为3.36。针对其中1项认知行为疗法研究、强化复发预防疗法及简短技术导向干预的PI结果可能并不可靠，原因在于相关试验结局为阴性。
**结论**：极性指数可用于量化某一干预措施的抑郁预防或（轻）躁狂预防偏向性，可为双相情感障碍个体化长期治疗中辅助心理疗法的选择提供参考依据。