Depression
Conditions
Brief summary
The investigators are examining whether the content of a visual scene impacts the antidepressant effects of light or if this impact is solely mediated by the intensity of the light.
Interventions
OTHERLight exposure
Participants will be exposed to 15 minutes of each arm. They will be exposed twice and a randomized order (1/2/1/2 or 2/1/2/1)
Sponsors
Stanford University
VA Palo Alto Health Care System
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Aged 18-60 * Mild depressive symptomatology
Exclusion criteria
* No depressive symptomatology * Severe depressive symptomatology * Active or unstable medical condition * Diabetes
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in mood | 15 minutes | Change in subjective mood as recored by the Positive and Negative Affect Schedule (PANAS). The PANAS ranges 10-50 on a positive mood scale (higher = more positive) and 10-50 on a negative mood scale (higher = more negative) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in fast brain electrical activity | 15 minutes | Change in the beta power spectrum (12.5-30 Hz) of the electroencephalogram (brain waves, measured in microvolts) |
| Change in systolic blood pressure (SBP) | 15 minutes | Change in SBP (mm Hg) as measured by finger plethysmography |
| Change in heart rate variability (HRV) | 15 minutes | Shift in the ratio of the power of low frequency to high frequency components in heart rate variability |
| Change in sympathetic activity | 15 minutes | Sympathetic activity will be imputed through the galvanic skin response (GSR). Change in skin conductance (the electrical activity on the skin) will be measured in microsiemens |
Countries
United States
Outcome results
None listed