Long-term Follow-Up: We have included a separate consent form to allow us to follow subjects over time. A main goal of the study is to better understand pain mechanics. Research has linked pro-inflammatory cytokines to the development and progression of pain. Research has also linked female gender with increases in pro-inflammatory cytokines (relative to males) following psychological stress. Therefore, we hypothesize that women in the study who evidence significantly increased pro-inflammatory cytokines following pain catastrophizing may be at risk for the progression of their pain condition. We expect that if we follow our sample over time, we will see a trend that will serve as preliminary data to allow us to investigate this further. While the catastrophizing experiment will provide us with meaningful data, this longitudinal sub study will allow us to define the clinical and functional relevance of our findings. For those who consent to this related study, subjects will be contacted every 6 months for up to 10 years and asked several questions about their pain, mood, function, and stress levels. They will also be asked to complete 4 questionnaires including: the Oswestry Disability Index, The CES-D form, and the Perceived Stress Scale. These questionnaires can be read to the subject over the phone or completed on paper. If the subject would like to complete them on paper, an address, stamped return envelope will be provided. They will also be asked if we can contact them again in 6 months.