Brief summary of evidence supporting the efficacy of biofeedback for Raynaud's Syndrome:
Freedman and his co-workers (Freedman et al 1970, 1981, 1985) did a series of studies showing that people with Raynaud's syndrome could learn to warm their hands, keep them at nearly normal temperatures for years, and keep them warm against cooling stresses. Their long term follow-up studies showed that people could help themselves avoid vasospastic attacks (and thus the symptoms of Raynaud's) for years.
Much of the information which follows is from Carolyn Yucha and Christopher Gilbert's 2004 book "Evidence Based Practice in Biofeedback Neurofeedback" AAPB, Wheat Ridge, CO.
Several brief, relatively uncontrolled studies seem to confirm the rationale underlying biofeedback treatment of Raynaud's disease. Peterson and Vorhies (1983) studied thermal biofeedback-trained Raynaud's patients, observing the speed of hand temperature return to baseline after hand immersion in ice water, which was six to seven times as fast after biofeedback training (6 minutes average after training vs. 40 minutes before). Jobe, Sampson, Roberts, and Kelly (1986) compared hand temperature responses to whole-body chilling before and after either classical or standard biofeedback ("operant") biofeedback training, and found that both approaches were effective. When Guglielmi, Roberts, and Patterson (1982) compared thermal biofeedback with EMG biofeedback and controls, with a double-blind procedure, all three groups had comparable improvements, suggesting a role of non-specific factors. Keefe, Surwit, and Pilon (1980) found similar results, in which other behavioral control methods performed as well as thermal biofeedback. However, Freedman et al (1988) compared simple thermal biofeedback with autogenic training and found the former more effective.
The largest study to date of Raynaud's involving biofeedback compared use of a calcium-channel blocker (nifedipine) with thermal biofeedback, EMG feedback, and a placebo (Raynaud's Treatment Study Investigators, 2000). In this study of 313 subjects with primary Raynaud's disease, nifedipine seemed to be the superior agent for reducing symptoms. Problems with training the thermal biofeedback subjects to an adequate level of skill, however, (Middaugh et al., 2001) mitigated the final results.