New research found that taking a placebo pill, knowing that it contains no active ingredients, reduced the intensity of premenstrual syndrome (PMS) symptoms by a whopping 79%, substantially more than taking the usual side-effect-causing medications.
We've covered a few studies into the seemingly miraculous effects of open-label placebos or OLPs, which people take for medical conditions, knowing full well that they contain zero active ingredients.
A recently published study led by researchers from the Faculty of Psychology at the University of Basel in Switzerland compared the effectiveness of OLPs and the usual treatment for premenstrual syndrome, commonly known as PMS.
“We conducted a randomized controlled trial to investigate the efficacy and safety of a six-week OLP intervention in women with moderate to severe PMS in comparison to treatment as usual for effects on symptom intensity and interference,” said the researchers.
PMS is characterized by physical (somatic) and psychological symptoms and affects, on average, 48% of women of reproductive age. Common psychological symptoms include irritability, depressed mood and mood swings; physical symptoms include breast tenderness, bloating, and joint pain. These symptoms can interfere with a woman’s ability to function socially, at school, and at work.
Treatments for PMS are varied, but first-line therapies include selective serotonin reuptake inhibitors (SSRIs) and hormonal agents like oral contraceptives and danazol. These treatments aim to address what is thought to be the condition’s underlying cause: an inadequate physiological response to hormone fluctuations. However, the side effects of these medications – dizziness, weight gain, nausea, and depression – cause many women to stop taking them.
For the recent study, 150 Swiss women with an average age of 25 were recruited from gynecologists’ practices and the University Hospital Basel’s gynecology outpatient clinic between March 2018 and December 2020. The women were eligible if they suffered from moderate to severe PMS or a severe form of PMS called premenstrual dysphoric disorder (PMDD), had a regular menstrual cycle, and had at least one psychological or somatic PMS symptom that impaired function and warranted treatment. The women were randomized into one of three groups: OLP with an explanation, OLP without an explanation, or treatment as usual, which meant continuing to take the PMS medication they were already taking. Here, the explanation given was of placebo effects and how placebos may decrease PMS symptoms. Both placebo-taking groups took two pink pills a day for six weeks.
The study’s primary outcome was changes from baseline in PMS symptom intensity and in how much PMS interfered with functioning at work, school, or socially across three menstrual cycles. To assess this, the researchers relied on participants’ self-reports, which included using a validated PMS Symptom Diary and scoring symptom intensity and interference on a Likert-type scale.
Receiving a placebo with an explanation reduced women’s symptom intensity by 79.3% and reduced symptom interference in their lives by 82.5%. Women who received a placebo without an explanation reported a 50.4% reduction in symptom intensity and a 50.3% reduction in interference. Those who continued treatment as usual fared the worst, with a 33% reduction in symptom intensity and a 45.7% reduction in interference caused by symptoms.
When the researchers looked at the effect of placebos on the intensity of psychological symptoms specifically, they found that women who received a placebo with an explanation saw a mean reduction of 70.66%; those who received a placebo without an explanation, a 42.60% reduction; and those maintaining treatment-as-usual had a 29.14% reduction. Participants in the placebo plus explanation group also had the greatest mean decrease in specific somatic symptom intensity (82.5%), followed by placebo without explanation (50.3%) and treatment as usual (45.7%).
“When examining psychological and somatic symptom intensity separately, our results indicated that both were improved by OLP with treatment rationale,” the researchers said. “This finding suggests a broad clinical applicability of OLP interventions with the potential to improve psychological and somatic symptom constellations.”
Four women in the placebo intervention groups reported non-serious adverse events three weeks after starting treatment that consisted of headache and gastrointestinal discomfort. No adverse events were reported after six weeks of treatment.
The researchers note that one of the study’s limitations is its reliance on self-report, which may have introduced social desirability bias. However, they still consider their findings important as they highlight the potential use of OLPs as a safe alternative PMS treatment.
“Administering OLPs with a treatment rationale to women with PMS can decrease symptom intensity and interference considerably in the absence of substantial side effects and with full transparency,” they concluded. “Considering our results as much as the individual and societal burden of PMS, OLP treatment could serve as an acceptable, efficacious, and safe intervention for PMS.”
The study was published in the journal BMJ Evidence-Based Medicine.
