Open-label placebos improve premenstrual syndrome

Doctors prescribe various medications and supplements to help alleviate the symptoms, from natural remedies and magnesium right through to antidepressants and hormonal treatments. But these treatments don't always help, and some of them have side effects such as drowsiness, nausea, weight gain, or depression, while hormonal treatments often have a negative impact on patients who want to have children. It's therefore important for every individual to weigh up which PMS treatment method is the most suitable for them.

"Nothing" can help

This premise was the starting point for a study by the Faculty of Psychology at the University of Basel. The team of researchers led by Dr. Cosima Locher, Professor Jens Gaab, and Dr. Antje Frey Nascimento collaborated with researchers from Harvard Medical School to investigate whether open-label placebo preparations could help those affected. The results appeared in the BMJ Evidence-Based Medicine scientific journal.

"Placebos are well researched since they are used in all drug trials. And they don't have any side effects," says Jens Gaab, highlighting some of the benefits. At the same time, the placebo effect shouldn't be underestimated. "Our brain has learned that if we take something regularly, it works -- even if it doesn't contain any active ingredients." Studies show that placebos can alleviate both physical and psychological complaints, even if they are administered as open-label, meaning that patients are aware that they're taking a tablet without any active ingredients. This has been demonstrated by randomized controlled studies relating to irritable bowel syndrome, chronic pain, and hot flashes during menopause, for example.

To find out whether open-label placebos (OLPs) can also help with PMS, the researchers carried out a study of 150 subjects between the ages of 18 and 45 who were moderately to severely affected by PMS. Participants in this study were women who were not taking psychotropics. They were split into three equally sized study groups at random.

The participants in the first group continued their previous treatments. The participants in the other two groups were given an OLP and could decide for themselves whether or not to continue their previous treatments. One of the two placebo groups was given the placebo pills without any additional information, whereas the other placebo group was informed of the reasons for using the placebo treatment during a consultation with the researchers that lasted approximately 20 minutes. The placebo pills were to be taken twice a day for six weeks.

Treatment without side effects

The open-label placebos alleviated the participants' symptoms both with and without the additional explanatory information, but the effect was greatest in women who received the information in addition to the placebo. In these women, the intensity of symptoms was reduced by up to almost 80 percent. "We weren't expecting the effects to be this pronounced," says study leader Dr. Antje Frey Nascimento. There was also a reduction in symptom intensity in the other two study groups, although the lowest effect was seen in women who simply carried on taking their previous medication.

The provision of treatment information, therefore made a significant difference. The study leader explains this as being due to the women feeling like they were being taken more seriously as a result of the treatment consultation, among other factors. The element of interpersonal communication between the attending physician and the patient, therefore seems to play an important role. "This is associated with a feeling of self-efficacy: my body is able to help itself." The study leader believes that this interaction between the body and the mind is an important element in treatment with OLPs.

All these factors make placebos a safe, effective, and patient-accepted intervention for PMS, particularly when combined with the provision of adequate information. The only catch: placebos have so far only been used in research. And even though we now have an initial indication of their effectiveness, we are still lacking important empirical evaluation relating to their use in clinical practice, as well as a clear legal foundation. Nevertheless, research with open-label placebos is on the rise, and researchers in Basel are keen to open up more potential areas of application.