In the study by O'Connor et al. participants with primarily IBS-D undergoing a group-based education program on the British Dietary Association's advice for IBS were less likely to achieve the 12-week primary endpoint (50-point reduction in the IBS Symptom Severity Scale) if they had elevated levels of depression or anxiety at baseline [1].

We appreciate the complex undertaking of evaluating psychological factors as part of dietary intervention, in pursuit of the growing need for personalised, integrated care for IBS [2]. Unfortunately, a few missed opportunities in the study design make it hard to reconcile the complex intersection between psychological “influencers” such as depression and anxiety, eating behaviours, IBS symptoms and response to dietary treatment.

First, reliance on the Hospital Anxiety and Depression Scale (HADS) > 8 as an indicator of psychiatric distress fails to consider the psychological nuances seen in patients with IBS, particularly with respect to their personal responses to gastrointestinal symptoms. Although generalised anxiety and major depression are associated with IBS [3], there seems to be a stronger relationship with symptom-specific anxiety, a well-established driver of IBS and a known risk factor for disordered/restricted eating behaviour [4]. Further, only baseline measures of depression and anxiety were considered, inhibiting the ability to determine the bi-directional and ongoing associations between depression, diet and IBS in response to intervention. Since there was no evaluation of whether anxiety and depression symptoms varied with IBS symptom severity after the intervention, it cannot be assumed that HADS scores were independent predictors of dietary response. Finally, the co-association of IBS symptom severity and symptoms of anxiety and depression at baseline begs the question of whether reductions in IBS symptoms were related to the reduction in symptoms of anxiety and depression due to following a healthy diet, which is quite plausible given the host of studies establishing the impact of diet interventions (e.g., Mediterranean diet) independently on psychological symptoms and well-being [3].

Finally, while the discussion section suggests that patients with greater severity of IBS symptoms may affect dietary behaviour (e.g., patients with more bothersome symptoms being more motivated to adhere to dietary guidance), there was no consideration of how symptoms of depression or anxiety (including fear of eating differently) may have the opposite effect on diet behaviour. Without data on dietary adherence over the 12-week intervention period, the team missed an opportunity to explore what, if any, relationships exist between motivation, symptom severity and depressive or anxiety symptoms.

There is certainly a need for more studies at the intersection of food and mood, particularly those that include measures of psychological distress, including symptom specific anxiety, measured at more frequent intervals. Future studies that consider the impact of mood and anxiety on dietary intervention motivation, adherence and adverse effects (e.g., eating disorder behaviour) would shed more light on these results, help to uncover the underlying mechanisms at play, and ideally lead to more personalised and more efficacious treatments.

在 O'Connor 等人的研究中，如果基线时抑郁或焦虑水平升高，则主要患有 IBS-D 的参与者根据英国饮食协会的 IBS 建议接受基于小组的教育计划，则不太可能达到 12 周的主要终点（IBS 症状严重程度量表降低 50 分）[1]。

我们赞赏评估心理因素作为饮食干预的一部分，以满足对 IBS 个性化、综合护理日益增长的需求 [2]。不幸的是，研究设计中错过了一些机会，这使得很难调和心理 “影响因素” 之间的复杂交叉点，如抑郁和焦虑、饮食行为、IBS 症状和对饮食治疗的反应。

首先，依赖医院焦虑和抑郁量表 （HADS） > 8 作为精神痛苦的指标，没有考虑 IBS 患者所看到的心理细微差别，特别是关于他们对胃肠道症状的个人反应。尽管广泛性焦虑和重度抑郁与 IBS 相关 [3]，但似乎与症状特异性焦虑有更强的关系，后者是 IBS 的公认驱动因素，也是饮食紊乱/限制性饮食行为的已知危险因素 [4]。此外，仅考虑了抑郁和焦虑的基线测量，抑制了确定抑郁、饮食和 IBS 之间响应干预的双向和持续关联的能力。由于没有评估干预后焦虑和抑郁症状是否随 IBS 症状的严重程度而变化，因此不能假设 HADS 评分是饮食反应的独立预测因子。最后，IBS 症状严重程度与基线时焦虑和抑郁症状的相互关联引出了一个问题，即 IBS 症状的减轻是否与遵循健康饮食导致的焦虑和抑郁症状的减轻有关，鉴于大量研究确定了饮食干预的影响（例如， 地中海饮食）与心理症状和幸福感无关 [3]。

最后，虽然讨论部分表明 IBS 症状更严重的患者可能会影响饮食行为（例如，症状更令人烦恼的患者更有动力遵守饮食指导），但没有考虑抑郁或焦虑症状（包括害怕不同饮食）如何对饮食行为产生相反的影响。由于没有关于 12 周干预期间饮食依从性的数据，该团队错过了探索动机、症状严重程度与抑郁或焦虑症状之间存在什么关系（如果有的话）的机会。

当然，有必要在食物和情绪的交叉点进行更多的研究，特别是那些包括心理困扰测量的研究，包括以更频繁的时间间隔测量的特定症状焦虑。未来考虑情绪和焦虑对饮食干预动机、依从性和不良反应（例如，饮食失调行为）的影响的研究将更清楚地了解这些结果，有助于揭示起作用的潜在机制，并理想地导致更加个性化和更有效的治疗。