The effects of melissa officinalis on depression and anxiety in type 2 diabetes patients with depression: a randomized double-blinded placebo-controlled clinical trial

BACKGROUND: Depression is more common in diabetic patients, with a 1.5-fold increased risk of death.Melissa officinalis (M. officinalis) have anti-diabetic and anti-depression activities. The study aimed to determine the efficacy of M. officinalis extract on depression, anxiety, and sleep quality in patients with type 2 diabetes with depressive symptoms. METHODS: In this double-blind clinical trial, 60 volunteer patients (age range 20–65 years) with type 2 diabetes mellitus with symptoms of depression were randomized into the intervention (received 700 mg/day hydroalcoholic extract; n = 30) or control group (received 700 mg/day toasted flour; n = 30). Dietary intake, physical activity, anthropometric indices, FBS (Fasting blood sugar), hs-CRP(High-sensitivity C-reactiveprotein), depression, anxiety, and sleep quality were determined at the beginning and end of the study. Depression and anxiety were assessed by Beck Depression Inventory-II (BDI-II) and Beck Anxiety Inventory (BAI), respectively; sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). RESULTS: Sixty participants received M. officinalis extract or placebo, of which 44 patients completed the 12-week double-blind clinical trial. After 12-week the mean change of depression and anxiety scores were statistically significant between the two groups (p < 0.001 and p = 0.04, respectively), but no significant differences were observed in FBS, hs-CRP, anthropometric indices, sleep quality, and blood pressure.In the intervention group, there was a significant decrease in depression and anxiety severity(p < 0.001 and p = 0.01, respectively) at the end of the study compared to the baseline. TRIAL REGISTRATION: All protocols in this study were followed in accordance with the Helsinki Declaration (1989 revision). Ethical approval for this study was obtained from the Iran University of Medical Sciences Ethics committee (IR.IUMS.FMD.REC 1396.9413468004; research.iums.ac.ir). The study was registered at the Iranian Registry of Clinical Trials (IRCT201709239472N16); Registration date: 09/10/2017. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12906-023-03978-x.