Predicting Effectiveness of Light Treatment for Winter Seasonal Affective Disorder
Condition: Depression
MeSH terms: Depression; Depressive Disorder; Mood Disorders; Seasonal Affective Disorder
Study type: Observational

Summary: 
      This study will evaluate a possible tool for predicting future effectiveness of bright light
      in treating seasonal affective disorder, winter subtype, and will examine secondary effects
      of bright light on cardiovascular risk factors.
    

Detailed description: 
      The winter subtype of seasonal affective disorder (SAD) is characterized by episodes of major
      depression in the fall and winter, with remission of these episodes in the spring and summer.
      SAD disrupts the lives of millions of Americans, who experience symptoms such as restless
      agitation, increased appetite and weight gain, and reduced energy and motivation. Bright
      light treatment, while shown to be effective in improving SAD in 75% of cases, only causes a
      full remission in 50% of cases. If doctors had a diagnostic tool to determine which patients
      would respond to bright light therapy, they could make better decisions about whether to
      prescribe bright light as treatment. This study will examine a possible diagnostic tool-a
      single, 1-hour bright light session-for predicting improvement in SAD symptoms over an
      extended course of bright light treatment. Additionally, because many symptoms of SAD (like
      weight gain and sedentary lifestyle) correspond to cardiovascular risk, this study will
      examine whether bright light treatment correlates with improved cardiovascular health.

      Participants with SAD will be randomly assigned to first receive a 1-hour session of either
      bright light or the placebo, red light. Then all participants will switch and receive a
      1-hour session of the other type of light. Red light has been accepted as a placebo in
      previous SAD studies because it does not suppress melatonin or shift circadian rhythms.
      Before and after each light session, participants will have their SAD symptoms evaluated in a
      clinical interview and self-report measure. After these two light sessions, all participants
      will receive instructions for administering bright light treatment on their own at home. For
      the next 6 weeks, participants will administer the bright light to themselves for 1 hour
      every morning. Every week they will undergo clinical interviews by phone and will mail in
      self-report measures, some completed daily and some weekly, to the researchers. The
      participants will have checkups and interviews in person on Weeks 4 and 6. At the two time
      periods, SAD symptoms and indicators of cardiovascular risk, such as appetite and sleep loss,
      will be evaluated. The participant responses to bright light and red light at the initial
      session will be compared with the participant responses to the subsequent 6-week treatment.
    

Intervention name(s): Bright light; Red light placebo
Intervention type(s): Device; Device
Intervention description(s): One hour of exposure to bright light daily upon awakening for 6 weeks.; One hour of exposure to red light.
Other intervention name(s): Brite light III light box (Apollo) 10,000 lux.; Dim red light box (Apollo) 50 lux.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with history of recurrent winter depression
      
Keywords: Seasonal Affective Disorder; Light Therapy; Seasonal Depression; Psychiatric Disorder; Bright Light; Major Depressive Disorder; Bipolar Disorder