Associations Between Pain, Current Tobacco Smoking, Depression, and Fibromyalgia Status Among Treatment-Seeking Chronic Pain Patients.

OBJECTIVE As smoking impacts physiological pathways in the central nervous system, it is important to consider the association between smoking and fibromyalgia, a pain condition caused predominantly by central nervous system dysfunction. The objectives were to assess the prevalence of current smoking among treatment-seeking chronic pain patients with (FM+) and without (FM-) a fibromyalgia-like phenotype; test the individual and combined influence of smoking and fibromyalgia on pain severity and interference; and examine depression as a mediator of these processes. METHODS Questionnaire data from 1566 patients evaluated for a range of conditions at an outpatient pain clinic were used. The 2011 Survey Criteria for Fibromyalgia were used to assess the presence of symptoms associated with fibromyalgia. RESULTS Current smoking was reported by 38.7% of FM+ patients compared to 24.7% of FM- patients. FM+ smokers reported higher pain and greater interference compared to FM+ nonsmokers, FM- smokers, and FM- nonsmokers. There was no interaction between smoking and fibromyalgia. Significant indirect effects of fibromyalgia and smoking via greater depression were observed for pain severity and interference. CONCLUSIONS Current smoking and positive fibromyalgia status were associated with greater pain and impairment among chronic pain patients, possibly as a function of depression. Although FM+ smokers report the most negative clinical symptomatology (i.e., high pain, greater interference) smoking does not appear to have a unique association with pain or functioning in FM+ patients, rather the effect is additive. The 38.7% smoking rate in FM+ patients is high, suggesting FM+ smokers present a significant clinical challenge.