• A 30% improvement in reported pain will be considered a treatment "success." As a secondary outcome, we will compare post-treatment pain scores between the UV and non-UV exposures given on the first day the dose is given (A vs. B in table 4).
  
• A treatment "success" in Phase 2 will be defined as a 30% reduction in pain relative to the baseline reported at screening on the 11-point pain scale.
  

• Detailed pain assessment
  
• Mood
  
• Quality of life
  
• Tanning blind
  

Fibromyalgia is a common chronic disorder characterized by widespread pain and fatigue. It occurs primarily in women, especially women of childbearing age. The effectiveness of treatment for this disorder is limited, and alternative medical treatments are commonly used.

Ultraviolet (UV) light exposure gives a sense of relaxation. It is unknown whether UV exposure has any effect on pain, particularly in patients with fibromyalgia. Through studies performed with RO3 funding from the National Institute of Drug Abuse (NIDA), we demonstrated that in frequent tanners, appearance is less important than UV-induced relaxation in motivating tanning behavior. Moreover, we determined that UV light has reinforcing properties apart from any psychosocial benefits of having a tan. One subject in our study reported low back pain relief from the UV exposure condition.

This is a two-year proposal that is the beginning of a long-term plan to assess whether indoor tanning ultraviolet light exposure has a therapeutic effect for patients with chronic pain. To this end, we will determine the effect of UV light on fibromyalgia pain in a controlled, double blind clinical trial of UV exposure. This approach is carefully designed to separate the effects of UV exposure on pain from potential confounds associated with the tanning procedure, including any perceived benefits of having a tan. The results of this study will increase our understanding of the specific influence of UV light on persistence in tanning behavior.