Bright Light Intervention to Reduce Students' Stress

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.

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.

Eligibility Criteria:
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