Behavioral activation based on the Health Action Process Approach – Efficacy of a theory-based online intervention in depression

行为激活是治疗抑郁症的一种非常有效的方法。然而，有一个显着的异质性的干预措施，被归类为“行为激活”的术语。本研究首次采用基于理论的行为激活干预（InterAKTIV）方法，对不同干预方法的干预效果进行了比较。干预措施以卫生行动程序方法为基础，并在网上实施，以确保广泛传播和标准化。本研究旨在调查抑郁症患者干预的有效性。主要结果是抑郁症的严重程度;次要结果是行为激活和HAPA过程变量。此外，将分析干预效果的调节因素。将进行平行设计的两组随机对照试验（RCT）。参与者将通过大型健康保险公司（AOK巴登-符滕贝格）的印刷和在线媒体招募。将确定符合入选标准的受试者（年龄：18-65岁，诊断为抑郁症，当前无心理治疗或精神药理学药物治疗变化，无排除诊断）。128名受试者的目标样本将随机分配至干预组（立即参加InterAKTIV）或等待名单对照组（在随访评估后参加InterAKTIV）。电话和在线评估在基线、随机化后两个月和六个月进行。初步分析将遵循意向治疗原则，本研究是第一个结合健康心理学和临床心理学的观点来评估基于理论的行为激活干预。它有助于进一步研究行为激活在德国和发展研究领域的一般。

Behavioral activation is a highly effective treatment in depression. Yet, there is a significant heterogeneity of interventions that are grouped under the term of “behavioral activation”. One main reason for the heterogeneity is a lack of theory in the intervention development: None of the established intervention manuals gives a theoretical rationale for their intervention techniques.For the first time, this study will use a theory-based behavioral activation intervention (InterAKTIV). The intervention is based on the Health Action Process Approach (HAPA) and is implemented online to ensure broad dissemination and standardization. The study aims at investigating the efficacy of the intervention in depressive people. Primary outcome is depression severity; secondary outcomes are behavioral activation and HAPA process variables. In addition, moderators of the intervention effects will be analyzed. A two-arm randomized controlled trial (RCT) of parallel design will be conducted. Participants will be recruited through print and online media of a large health insurance company (AOK Baden-Württemberg). Participants fulfilling the inclusion criteria (age: 18-65 years, diagnosis of depression, no current psychotherapy or changes in psychopharmacologic medication, none of the exclusion diagnoses) will be identified. A target sample of 128 participants will be randomized to either intervention (immediate participation in InterAKTIV) or wait list control (participation in InterAKTIV after follow-up assessment). Telephone and online assessments take place at baseline, two months and six months after randomization. Primary analyses will follow the intention-to-treat principle.The study is the first to evaluate a theory-based behavioral activation intervention by combining perspectives from health psychology and clinical psychology. It contributes to further research on behavioral activation in Germany and to develop the field of research in general.