Acupuncture for emotional symptoms in patients with functional gastrointestinal disorders: A systematic review and meta-analysis

Functional gastrointestinal disorders represent a complex group of conditions affecting more than 40% of the world's population, characterized by persistent digestive symptoms without identifiable structural alterations in digestive system organs. These conditions, which include irritable bowel syndrome, functional dyspepsia, functional constipation, and functional diarrhea, are currently understood as disorders of gut-brain interaction. A striking feature of these problems is that they are frequently accompanied by significant emotional symptoms such as anxiety and depression, creating a vicious cycle in which physical symptoms worsen the emotional state and vice versa. Conventional pharmacological treatments, although effective for specific digestive symptoms, have important limitations in managing emotional aspects, creating the need for more comprehensive therapeutic approaches.

This study aimed to systematically evaluate the clinical efficacy and safety of acupuncture in the treatment of emotional symptoms in patients with functional gastrointestinal disorders. The researchers conducted a systematic review and meta-analysis, searching for randomized controlled clinical trials in eight different databases, both in English and Chinese, from inception through July 2021. Studies that compared acupuncture with sham acupuncture (where needles are superficially inserted at non-therapeutic points) or with conventional pharmacological treatment were included. Researchers used validated scales to measure anxiety and depression, such as self-rating anxiety and depression scales, among others.

The methodology followed rigorous scientific standards, including assessment of study quality and appropriate statistical analyses to combine results from different studies.

The analysis included 24 clinical trials with a total of 2,151 patients, covering treatment periods ranging from 2 to 10 weeks. The results revealed interesting and apparently contradictory findings. When acupuncture was compared with sham acupuncture, there were no statistically significant differences in the reduction of anxiety or depression symptoms, suggesting that the benefits observed may be related to nonspecific effects of the technique. On the other hand, when compared with conventional pharmacological treatment, acupuncture demonstrated significant superiority in reducing both anxiety and depression symptoms.

Additional subgroup analyses showed that acupuncture was more effective than medications for anxiety across all studied conditions and for depression in most of them, except for functional constipation. Interestingly, efficacy did not depend on including specific calming acupuncture points or on the type of acupuncture used, whether manual or with electrical stimulation.

These results have important clinical implications for both patients and healthcare providers. For patients, acupuncture emerges as a potentially valuable therapeutic option, especially considering its favorable safety profile, with few adverse effects reported and no serious events recorded across the analyzed studies. Acupuncture may be particularly attractive for patients seeking alternatives to conventional medications or who have not obtained adequate relief of emotional symptoms with pharmacological treatments. For healthcare providers, these findings suggest that acupuncture may be considered as part of an integrated approach in the treatment of functional gastrointestinal disorders, especially when there are significant emotional components.

The technique may be especially useful by simultaneously addressing both digestive and emotional symptoms, potentially breaking the vicious cycle that characterizes these conditions.

However, this study has important limitations that should be considered when interpreting the results. The vast majority of included trials were conducted in China, which may limit the generalizability of findings to other populations and cultural contexts. In addition, most studies were small and conducted at single centers, which may affect the robustness of the conclusions. A significant methodological limitation is the inherent difficulty in creating truly "blinded" control groups in acupuncture studies, since both patients and therapists know which treatment is being administered.

This may introduce biases related to expectations and placebo effects. The fact that acupuncture did not show superiority over sham acupuncture raises important questions about mechanisms of action, suggesting that the observed benefits may be more related to nonspecific effects than to specific actions of the acupuncture points used. The researchers acknowledge that future studies with more rigorous design, larger samples, and greater geographic diversity are necessary to definitively clarify the role of acupuncture in treating emotional aspects of functional gastrointestinal disorders.