Effects of aromatherapy on depression: A meta-analysis of randomized controlled trials

Non-pharmacological interventions, such as aromatherapy, have been utilized for treating depression. This systematic review and meta-analysis aimed to investigate the effects of aromatherapy on depressive symptoms. The databases of PubMed, MEDLINE, CINAHL, EMBASE, Web of Science, and the Cochrane Library were searched from May 5, 2023, to May 20, 2023. Only randomized controlled trials that implemented aromatherapy in adults aged ≥18 years were included. The standardized mean difference (SMD) was calculated, and subgroup analysis, meta-ANOVA, and meta-regression were performed for the moderator variables. Thirty-two clinical trials (27 studies) were included in the final analysis. Aromatherapy demonstrated a moderate effect size for reducing depressive symptoms (SMD = −0.56, 95% CI: −0.69 to −0.43). Inhalation was the most effective method of delivery and blended essential oils were more effective than lavender or other single essential oils. Aromatherapy demonstrated a moderate effect size for reducing depressive symptoms among menopausal women, patients with heart disease (coronary artery disease or acute coronary syndrome), and psychological illnesses. However, it demonstrated no effect on postpartum or pregnant women. Mean age was a significant moderator variable. Reliable evidence is present for the application of aromatherapy to reduce depressive symptoms, and it can be utilized effectively to decrease depressive symptoms.