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

Area of Science:

• Psychology
• Nursing
• Complementary Medicine

Background:

• Olfactory training (OT) and aromatherapy (AT) utilize repeated odorant exposure for psychological well-being.
• These noninvasive methods are explored as potential interventions for managing depressive symptoms.

Purpose of the Study:

• To conduct a scoping review on the use of OT/AT for reducing depressive symptoms.
• To summarize intervention characteristics and identify literature gaps in OT/AT research for depression.

Main Methods:

• A comprehensive literature search was performed across major databases (PubMed, CINAHL, Scopus, PsycINFO) from 2000-2026.
• 29 peer-reviewed interventional studies were synthesized following PRISMA-ScR guidelines, focusing on depressive symptomatology outcomes.

Main Results:

• A majority of studies (22/29) indicated improvements in depressive symptoms (mean Cohen's d = 0.41).
• Effectiveness varied, with some studies showing only within-group improvements, likely due to differences in intervention protocols (e.g., duration, odorants, frequency).
• Inconsistent reporting hindered the assessment of adherence to OT/AT protocols.

Conclusions:

• OT/AT are simple, affordable interventions beneficial for reducing depressive symptoms in vulnerable groups, excluding moderately severe outpatient depression.
• These therapies align with holistic nursing by integrating sensory and emotional aspects for mental health improvement.
• Methodological standardization and adherence monitoring are lacking, underscoring the need for rigorous randomized controlled trials to confirm therapeutic benefits.