Effects of a traditional herbal formula containing Melissa officinalis, Pimpinella anisum, and Rosa damascena on anxiety and depression in patients with constipation-predominant irritable bowel syndrome (IBS-C): A double-blind randomized clinical trial

Introduction: Irritable bowel syndrome (IBS) is associated with a high prevalence of anxiety and depression. This study aimed to evaluate the effects of a traditional Persian herbal formula containing Melissa officinalis, Pimpinella anisum, and Rosa damascena (MPR) on anxiety and depression in IBS patients with symptoms of constipation-predominant IBS (IBS-C).

Methods: This double-blind randomized clinical trial was conducted in Afzalipour Hospital via block randomization method. A total of 96 IBS-C patients (based on Rome IV criteria), aged 18-60 years, were included in this study. Participants received capsules containing either 500 mg of herbal formula or placebo (cornstarch) twice a day for four weeks Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale.

Results: Forty-three patients in the intervention group and 45 patients in the control group completed this study. Except for the education level, there were no significant differences in the demographic characteristics between the two groups (P > 0.05). The mean levels of anxiety and depression, and total IBS symptom severity score showed no significant differences between the two groups at baseline (P > 0.05). After four weeks of treatment, the anxiety score considerably improvement in the treatment group (Cohen's d = -1.19, 95 % confidence intervals [CIs] -4.49 to 2.13), as did the depression score (Cohen's d = -1.93, 95 % CIs -4.32 to 2.79).

Conclusion: MPR considerably improved anxiety and depression in patients with IBS-C compared to the placebo without serious side effects.