Premenstrual syndrome (PMS) is a common condition affecting many women, characterized by a range of distressing symptoms. In 1999, placebo-controlled, crossover clinical trial conducted by M. J. Walsh and B. I. Polus, the efficacy of chiropractic therapy in treating PMS symptoms was rigorously investigated.

The study enrolled 25 subjects diagnosed with PMS, utilizing the Moos premenstrual syndrome questionnaire along with daily symptom monitoring for confirmation. The research was carried out in multicenter private clinics, and the subjects were randomly assigned to two groups.

One group, consisting of 16 subjects, received high-velocity, low-amplitude spinal manipulation coupled with soft tissue therapy. This intervention was administered 2 to 3 times in the week preceding menstruation for at least 3 cycles. The remaining 9 subjects were administered a placebo treatment, utilizing a spring-loaded adjusting instrument with minimal force. Following a 1-cycle washout period, the two groups switched interventions.

The primary outcome measure was the daily rating of symptom levels, comparing total scores during the premenstrual week with baseline scores for both treatment and placebo phases. Data analysis employed paired Student t tests and Wilcoxon signed rank tests, with statistical significance set at P < .05.

Results revealed a significant decrease in symptom scores after treatment compared to baseline scores (P = .00001). Moreover, a statistically significant reduction in scores during the treatment phase was observed when compared to the placebo phase (P = .006). For the group receiving chiropractic treatment (n = 16), there was a notable decrease in scores after treatment compared to baseline (P = .0001), and a statistically significant difference was observed between treatment and placebo scores (P = .041). In contrast, for the placebo group (n = 9), a significant decrease in scores during treatment compared to baseline was evident (P = .01), but no statistically significant difference was found between treatment and placebo scores at the P = .05 level.

The conclusions drawn within the limitations of the study suggest that chiropractic treatment, comprising adjustments and soft-tissue therapy, may generally reduce symptoms associated with PMS. However, the role of the placebo effect requires further exploration, as the group receiving the placebo first, while improving over the baseline, did not exhibit additional improvement when they subsequently received actual treatment. This study contributes valuable insights into the potential efficacy of chiropractic therapy for managing PMS symptoms, warranting further investigation.

Reference: Walsh, M. J., & Polus, B. I. (1999). A randomized, placebo-controlled clinical trial on the efficacy of chiropractic therapy on premenstrual syndrome. Journal of manipulative and physiological therapeutics, 22(9), 582-585.