Bright Light Intervention to Reduce Students' Stress (BLISS)

Effects of Bright Morning Light Exposure on Students' Stress, Mood, Anxiety, Sleep and, Circadian Rest-activity Cycle

Increased stress levels are a significant problem for many students and represent a risk factor for impaired mental and physical health as well as academic performance. Stress levels are particularly high during the preparation phase for major exams.

There is good evidence that light therapy is an effective treatment option to improve mood in affective disorders.

The present study aims at investigating the psychophysiological effects of a 3-week morning bright light exposure in reducing stress and stress-related problems in students preparing for major exams.

Study Overview

• Status: Recruiting
• Conditions: Psychological Stress; Sleep Disorders, Circadian Rhythm; Physiological Stress
• Intervention / Treatment: Other: Bright light intervention; Other: Reddish placebo light

Detailed Description

Increased students' stress represents a significant risk factor for impaired mental and physical health as well as academic performance. The World Mental Health Survey (WHO) reports a 12-month prevalence of mental illness of 20.3% among students, with anxiety disorders (14.7%), affective disorders (9.9%), and substance abuse (6.7%) being particularly prominent. Moreover, six out of 10 students suffer from impaired sleep quality.

Offering an effective treatment for stress-related symptoms in students is a challenge. In situations of intense stress, conventional methods such as relaxation and mindfulness-based programs often fail because of poor prior practice. Only a few students apply cognitive behavioral interventions. Although medication might decrease stress symptoms within days, the side effects of drugs cannot be ignored. Therefore, there is a need for effective and efficient treatment of acute stress symptoms in students.

Bright light therapy is an effective treatment for several mental disorders, e.g. affective disorders and sleep disorders. There is some evidence, that exposure to bright light may even reduce stress in patients with burnout symptoms. Thus, exposure to bright light may be a promising new option to reduce academic stress and improve mood and sleep parameters.

In the present study, a large-area desk lamp, which emits diffuse light and is controllable in its luminance and correlated color temperature is used. Study participants are randomly assigned to one of three study arms: (i) exposure to polychromatic light of 5,000 lux and 5,300 Kelvin, (ii) exposure to polychromatic light of 50 lux and 2,200 Kelvin, or (iii) no light intervention. Data collection takes place in winter periods.

• Study Type: Interventional
• Enrollment (Estimated): 125
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Markus Canazei, PhD; Phone Number: 56060 0043-512-507; Email: markus.canazei@uibk.ac.at

Study Locations

• Austria
  • Tyrol
    • Innsbruck, Tyrol, Austria, 6020
      • Recruiting
      • University of Innsbruck
      • Contact: Markus Canazei, PhD; Phone Number: 56060 0043-512-507; Email: markus.canazei@uibk.ac.at
      • Contact: Inge Pfanzelt; Phone Number: 56005 0043-512-507; Email: Inge.Pfanzelt@uibk.ac.at

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• students from the faculty of medicine, pharmacy, and law
• major exam at least 5 weeks ahead
• possession of smartphone and data plan

Exclusion Criteria:

• major depressive disorder (PHQ-9): Score > 4
• suicidal ideation (BDI, Item i): Rating > 1
• seasonal affective disorder (PIDS-A): Score > 11
• taking medication which increases photo-sensitivity
• taking medication to increase cognitive performance
• starting or changing pharmacotherapy for affective disorders and anxiety disorders within the last two weeks
• changing of all kinds of medication within the last two weeks
• headache (PHQ-D, Item f): Rating "severly impaired"
• increased light sensitivity: Item "Wearing sunglasses outside on sunny days" is answered with 'often' or 'very often'
• currently undergoing psychotherapeutic treatment
• the presence of an eye disease for which light therapy is contraindicated

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: bright white light intervention; exposure to 5,000 lux with polychromatic white light with 5,300 Kelvin at eye level; light exposure starts immediately after awakening; light exposure takes place on weekdays (Monday till Friday) over a period of 3 weeks	Other: Bright light intervention; Exposure with 5,000 lux at eye level for one hour and a Correlated Color Temperature of 5,300 Kelvin every morning for three weeks.
Placebo Comparator: dim reddish light intervention; exposure to 50 lux with polychromatic reddish light with 2,200 Kelvin at eye level; light exposure starts immediately after awakening; light exposure takes place on weekdays (Monday till Friday) over a period of 3 weeks	Other: Reddish placebo light; Exposure with 50 lux at eye level for one hour and a Correlated Color Temperature of 2,200 Kelvin every morning for three weeks.
No Intervention: no light intervention; no light intervention takes place in the morning; the study participants follow their natural rhythm of life

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
subjective stress level - baseline/post	Perceived Stress Scale (PSS-10); scale: PSS-10 sum score; range:0 - 40; higher scores mean a higher subjective stress level	Change from baseline PSS-10 sum score at the end of week 3
subjective stress level - baseline/post	Perceived Stress Questionnaire (PSQ-20); scale: PSQ-20 sum score; range: 20 - 80; higher scores mean a higher subjective stress level	Change from baseline PSQ-20 sum score at the end of week 3
subjective stress level - on weekdays	Perceived Stress Questionnaire (PSQ-20); scale: PSQ-20 sum score; range: 20 - 80; higher scores mean a higher subjective stress level	Change of daily PSQ-20 sum score at each weekday during the light intervention period up to 3 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
anxiety	State-Trait Anxiety Inventory (STAI - form Y) - 20 trait items; scale: STAI-trait sum score; range: 20 - 80; higher scores mean a higher subjective anxiety level	Change from baseline STAI-trait sum score at the end of week 3
mood	Center for Epidemiologic Studies Depression Scale (CES--D); scale: CES-D sum score; range: 0 - 60; higher scores mean a higher subjective depression level	Change from baseline CES-D sum score at the end of week 3
sleep quality	Pittsburgh Sleep Quality Index (PSQI); scale: global PSQI score; range: 0 - 21; higher scores mean a lower subjective sleep quality	Change from baseline global PSQI score at the end of week 3
sleep quality - total sleep time	Wrist actimetry to measure daily total sleep time (TST); scale: sleep duration; range: >0 (minutes); higher TST means longer sleep period	Change of TST at each night during the light intervention period up to 3 weeks
sleep quality - sleep onset latency	Wrist actimetry to measure daily sleep onset latency (SOL); scale: duration to fall asleep; range: >0 (minutes); higher SOL means longer period to fall asleep	change of SOL at each night during the light intervention period up to 3 weeks
sleep quality - wake after sleep onset	Wrist actimetry to measure daily wake after sleep onset (WASO); scale: duration of being awake during sleep period; range: greater than or equal to 0 (minutes); higher WASO means longer wake periods after sleep onset	change of WASO at each night during the light intervention period up to 3 weeks
sleep quality - sleep efficiency	Wrist actimetry to measure daily sleep efficiency (SE); scale: percentage; range: 0 - 100; higher SE means a higher undisturbed sleep	change of SE at each night during the light intervention period up to 3 weeks
circadian rest/activity rhythm - interdaily stability	Circadian rest-activity cycle parameter interdaily stability (IS) derived from weekly wrist actimetry data; scale: real number; range: 0 -1; higher IS means a higher stability in daily rest-activity cycles	change of IV at each of the three light intervention weeks up to 3 weeks
circadian rest/activity rhythm - intradaily variability	Circadian rest-activity cycle parameter intradaily variability (IV) derived from averaged wrist actimetry data over a period of 1 week; scale: real number; range: 0 - 2; higher IV means a higher variability in 24-h rest-activity cycle	change of IS at each of the three light intervention weeks up to 3 weeks
physiological stress reaction	cortisol level measured from hair sample; scale: real number (pg/mg); range: >0; higher hair cortisol level means higher physiological stress	Change from baseline hair cortisol level at the end of week 3
adverse effects - short-term	astenopic complaints measured with 12 items; scale: sum score; range: 10 - 60; higher sum score means more astenopic complaints	day 5
adverse effects - long-term	astenopic complaints scale measured with 12 items: sum score; range: 10 - 60; higher sum score means more astenopic complaints	day 15

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
resilience	Resilience Scale (RS-11); scale: RS-11 sum score; range: 11 - 77; higher RS-11 sum score means more perceived resilience	Change from baseline RS-11 sum score at the end of week 3
stress coping	Coping Inventory for Stressful Situations (CISS) - 24 items; three-dimensional CISS scale: (a) task-oriented coping; (b) emotion-oriented coping, and (c) avoidance-oriented coping; range for each dimension: 8 - 40; higher score in each dimension means higher preference for particular stress coping style	Change from baseline multidimensional CISS scale at the end of week 3
learning strategies	Learning Strategies of University Students (LIST-K) - 36 items; multidimensional LIST-K scale: 13 subscales; range for each dimension: 3 - 15; higher score in each dimension means higher preference for particular learning strategy	Change from baseline multidimensional LIST-K scale at the end of week 3
psychological distress	Brief Symptom Inventory (BSI-18); scale: BSI-18 sum score; range: 18 - 90; higher BSI-18 sum score means higher psychological distress	Change from baseline BSI-18 overall score at the end of week 3
somatic symptoms	The somatic symptom scale (SSS-8); scale: SSS-8 sum score; range: 0 - 32; higher SSS-8 sum score means higher somatic complaints	Change from baseline SSS-8 sum score at the end of week 3
satisfaction with light intervention - short-term	2 items: (a) recommendation of light intervention to a friend and (b) follow-up usage of light intervention for own purposes; scale: binary score ('yes', 'no'); range: 0 - 1; higher binary scores indicate recommendation and follow-up usage of the light intervention	day 5
satisfaction with light intervention - long-term	2 items: (a) recommendation of light intervention to a friend and (b) follow-up usage of light intervention for own purposes; scale: binary score ('yes', 'no'); range: 0 - 1; higher binary scores indicate recommendation and follow-up usage of the light intervention	day 15
daily mood state	Positive and Negative Affect Schedule (PANAS); two-dimensional PANAS scale: sum score for positive and negative mood state; range for each dimension: 10 - 50; higher PANAS scores mean higher positive and negative mood state, respectively	changes from before the light intervention of the two-dimensional PANAS scale at the end of light intervention at each weekday during the light intervention period up to 3 weeks
weekly social rhythms	The Social Rhythm Metric (SRM) measures the regularity in the occurance of 17 daily events; scale: SRM score; range: 0 - 7; higher SRM scores mean more regular occurance of daily events	changes in SRM scores in week 1, week 2, and week 3
anxiety state	State-Trait Anxiety Inventory (STAI - form Y) - 20 state items; scale: STAI-state sum score; range: 20 - 80; higher scores mean a higher subjective current anxiety level	changes from before the light intervention STAI-state sum score at the end of light intervention in week 1, week 2, and week 3
cognitive performance	The Number Letter Task (NLT) measures task switching performance; scale: number of correct answers; range: integer greater than or equal to 0; higher NLT scores means a better task switching performance	changes from before the light intervention NLT number of correct answers at the end of light intervention in week 1, week 2, and week 3
exam anxiety	German Test Anxiety Inventory (PAF); four-dimensional PAF scale: (a) excitement, (b) concern, (c) interference, and (d) lack of confidence; range for each dimension: 5 - 20; higher scale means higher test anxiety in the corresponding dimension	changes of multidimensional PAF scale at week 1, week 2, and week 3

Collaborators and Investigators

• Sponsor: Universitaet Innsbruck
• Collaborators: Bartenbach GmbH
• Investigators: Principal Investigator: Markus Canazei, PhD, University of Innsbruck

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2020
• Primary Completion (Estimated): March 31, 2024
• Study Completion (Estimated): October 31, 2024

Study Registration Dates

• First Submitted: April 29, 2021
• First Submitted That Met QC Criteria: May 19, 2021
• First Posted (Actual): May 25, 2021

Study Record Updates

• Last Update Posted (Actual): September 18, 2023
• Last Update Submitted That Met QC Criteria: September 14, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Keywords: stress; light therapy
• Additional Relevant MeSH Terms: Behavioral Symptoms; Mental Disorders; Nervous System Diseases; Dyssomnias; Neurologic Manifestations; Occupational Diseases; Chronobiology Disorders; Sleep Wake Disorders; Stress, Psychological; Sleep Disorders, Circadian Rhythm
• Other Study ID Numbers: 878649

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No