Acceptance and Commitment Therapy (ACT) is potentially effective for treating chronic fatigue. Given the paucity of studies on this topic, we aimed to assess long‐term trajectories of primary (fatigue, quality of life and functional abilities) and secondary outcomes (anxious and depressive symptoms) of an ACT‐based rehabilitation program for patients with chronic fatigue. Further, we examined if changes in potential process variables (psychological inflexibility, metacognitive beliefs, and cognitive and behavioral responses to symptoms) during ACT predicted change in all outcomes across follow‐up. One‐hundred ninety‐five workers on sick leave (mean age: 43.61 ± 9.33 years; 80.5% females) with a diagnosis of chronic fatigue were enrolled in a manualized, 3.5‐week intensive return‐to‐work rehabilitation program based on ACT. All completed a battery of questionnaires at pre‐, post‐treatment, 6 and 12 months follow‐up. We found significant longitudinal changes in most primary and secondary outcomes from pre‐ up to 12 months follow‐up. All process variables significantly decreased from pre‐ up to 12 months follow‐up, and pre‐to‐post changes in fear avoidance beliefs were most often associated with a greater change in outcomes across follow‐up. Depressive symptomatology showed a similar trajectory of change to fatigue, meaning that scores were correlated at each time point and tended to converge over time. This suggests that both symptoms influence each other substantially over a year following the treatment. Concluding, results lend support to the effectiveness of an ACT‐based rehabilitation program for patients with chronic fatigue and provide preliminary evidence for the role of process variables and depressive symptomatology on subsequent change in outcomes.

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基于ACT的康复计划治疗慢性疲劳的有效性：一项为期12个月的纵向研究得出的结果。

接受和承诺疗法（ACT）可能有效治疗慢性疲劳。鉴于对该主题的研究较少，我们旨在评估基于ACT的慢性疲劳患者康复计划的主要（疲劳，生活质量和功能能力）和次要结果（焦虑和抑郁症状）的长期轨迹。此外，我们检查了ACT期间潜在过程变量（心理上的不灵活性，元认知信念以及对症状的认知和行为反应）的变化是否预测了随访中所有结局的变化。一百九十五名病假的工人（平均年龄：43.61±9.33岁；女性为80.5％）被诊断为慢性疲劳，参加了一项基于ACT的为期3.5周的手动重返工作康复计划。所有患者均在治疗前，治疗后，6和12个月的随访中完成了一系列问卷调查。我们发现从随访前到随访12个月，大多数主要和次要结局都有明显的纵向变化。从随访前到随访12个月，所有过程变量均显着降低，而回避恐惧信念的前后变化通常与整个随访结果的较大变化有关。抑郁症状表现出相似的疲劳变化轨迹，这意味着得分在每个时间点都相关，并且随着时间趋于收敛。这表明在治疗后的一年中，这两种症状会相互影响。最后，