Olfactory Training and Aromatherapy for Treating Depressive Symptomatology: A Scoping Review

BackgroundRepeated exposure to odorants through olfactory training (OT) and aromatherapy (AT) represents a noninvasive approach for psychological well-being.ObjectiveThis scoping review investigated how OT/AT can be used to reduce depressive symptoms, summarized intervention characteristics reported in the literature, and pointed out gaps in the literature.MethodsA scoping review of the literature published between 2000 and 2026 was conducted using a broad search across PubMed, CINAHL, Scopus, and PsycINFO based on inclusion/exclusion criteria on June 17, 2025, and April 13, 2026. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews guidelines, 29 peer-reviewed interventional studies examining depressive symptomatology outcomes were synthesized.ResultsMost studies (e.g., 22/29) demonstrated improvements in depressive symptomatology (Cohen's d = -0.90 to 1.56; mean Cohen's d = 0.41); however, these effects were not consistently greater than control conditions, as several studies reported only within-group improvements. Results varied likely due to protocol differences (i.e., OT/AT sessions per day/week, odorant types, total intervention durations, measurement tools). Assessing adherence to OT/AT was challenging due to incomplete reporting across studies.ConclusionsThe OT/AT are simple, noninvasive, and relatively affordable interventions for reducing depressive symptoms in several vulnerable populations, except in clinically diagnosed depressive outpatients with moderate symptom severity. The OT/AT aligns with holistic nursing principles by integrating the sensory and emotional components to improve mental health and overall well-being. There is a lack of methodological standardization and inconsistency in monitoring adherence to OT/AT; thus, more rigorous randomized controlled trials are needed to examine its therapeutic benefit.ImpactThis scoping review contributes to future nursing research priorities and provides evidence for integrating OT/AT into holistic nursing practice.