The Effects of Smell on Mood and Physical Responses

National Institutes of Health (NIH)

Status and phase: Completed; Phase 1

Conditions: Depression; Anxiety; Stress

Treatments: Behavioral: Exposure to relaxant and stimulant odors

Study type: Interventional

Funder types: NIH

Identifiers

NCT00097253

R21AT002122-01

Details and patient eligibility

About

The purpose of this study is to examine the body's response to relaxing and stimulating fragrances commonly used in aromatherapy.

Full description

Despite aromatherapy's popularity, efficacy data are scant, and potential mechanisms are controversial. This randomized controlled trial examined the psychological, autonomic, endocrine, and immune consequences of one purported relaxant odor (lavender), one stimulant odor (lemon), and a no-odor control (water), before and after a stressor (cold pressor); 56 healthy men and women were exposed to each of the odors during three separate visits. To assess the effects of expectancies, participants randomized to the "blind" condition were given no information about the odors they would smell; "primed" individuals were told what odors they would smell during the session, and what changes to expect. Experimenters were blind.

In each case we measured several different aspects of the cellular immune response, as well as skin barrier repair following tape stripping. This design allowed us to examine the ability of the odors to modulate endocrine and immune function, and health-relevant cutaneous responses.

Enrollment: 56 patients

Sex: All

Ages: 18 to 44 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy adults with a normal sense of smell

Exclusion criteria

• Treatment with medication that has immunological or endocrinological consequences
• Chronic health problems that affect immune or endocrine systems
• Allergy to perfume or cosmetics
• Problems with sense of smell
• Respiratory problems
• Smoker
• Current active asthma
• Use of psychoactive drugs or mood-altering medication
• History of anxiety disorder, major depression, bipolar disorder, schizophrenia, or other psychotic disorders
• History of chest pain or ventricular fibrillation

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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56 participants in 3 patient groups, including a placebo group

Lavender

Experimental group

Treatment:

Behavioral: Exposure to relaxant and stimulant odors

Citrus

Experimental group

Treatment:

Behavioral: Exposure to relaxant and stimulant odors

Water

Placebo Comparator group

Treatment:

Behavioral: Exposure to relaxant and stimulant odors