The Effects of Smell on Mood and Physical Responses

Phase 1

Completed

Conditions: Anxiety
Depression
Stress

Interventions: Behavioral: Exposure to relaxant and stimulant odors

Registration Number: NCT00097253

Lead Sponsor: National Center for Complementary and Integrative Health (NCCIH)

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

Detailed 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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 56

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Water	Exposure to relaxant and stimulant odors	-
Lavender	Exposure to relaxant and stimulant odors	-
Citrus	Exposure to relaxant and stimulant odors	-

Primary Outcome Measures

Name	Time	Method
Immune Function: Delayed Hypersensitivity to Candida(DTH)	Day 1 11:45, Day 2 (24h) 11:45, Day 3 (48h) 11:45, Day 4 (72h) 11:45.	DTH memory responses to a common infectious agent provided a measure of T-cell immunity. Nurses inoculated subject's arm with 0.1ml Candida (stock solution diluted 1:20 in saline, Greer Labs, NC) intradermally, after the cold pressor stressor. The wheal diameter (2 dimensions) was self-assessed at 24, 48, and 72 hours by participants given detailed instructions and templates for measurement.
Cortisol and Catecholamine Production	3 Visits with at least 2 weeks between each. Average time to complete all visits was 64.46 days (SD 48.4). Cortisol: 9:05, 10:05, 10:55, 11:45, 12:15, 13:00. Nor/Epi: 9:05, 10:05, 10:55, 11:05, 11:45, 12:15	Cortisol, norepinephrine, epinephrine measured before and after physical (cold pressor) stressor, which occurred at 11:00.
Skin Barrier Repair	3 Visits with at least 2 weeks between each. Average time to complete all visits was 64.46 days (SD 48.4).10:05, 11:45, 13:15	TEWL (Transepidermal Water Loss, via tape stripping procedure)measured before and after cold pressor stressor (11:00). After obtaining baseline measurements on volar forearm, cellophane tape(3M Scotch-type; St. Paul, MN) was applied repeatedly (6-50 times) to remove superficial layer of cornified skin cells. Tape stripping stopped when TEWL was elevated from the basal level of 5-7 g/h/m2 to at least 20 g/h/m2. The number of strips required to reach TEWL X20 g/m2/h was the measure of barrier. TEWL was measured with a computerized evaporimetry instrument, the DermaLabs (CyberDERM, Media, PA).
Immune Function	3 Visits with at least 2 weeks between each. Average time to complete all visits was 64.46 days (SD 48.4). 9:05, 10:05, 11:45	Stimulated Cytokine Production (Interleukin-6 (IL-6), Interleukin-10 (IL-10)) measured before and after cold pressor stressor, which occurred at 11:00.