Randomised trial, 1999
How many women with severe PMS improve from taking a placebo pill?
About 20% show significant lasting improvement (at least 50% reduction in symptoms), 42% partially improve, and 39% don't improve. If you improve for at least 2 consecutive months, you are likely to keep improving.
What they did
Pooled analysis of 101 women from two randomized controlled trials who met criteria for severe PMS. All remained eligible after 1 month of single-blind placebo lead-in treatment. They then received 3 months of double-blind placebo treatment.
What they found
20% of placebo-treated subjects showed sustained improvement (at least 50% decrease in symptom score), with 18 of these improving for at least 3 of the 4 months of placebo treatment. Another 42% partially improved. 39% were clearly unimproved throughout the study period.
What it means for you
Placebo helps some people significantly, but only about 1 in 5. The results show that non-drug factors and patient expectations matter in treatment. However, these women had already shown some placebo response during the lead-in phase, so results may not apply to all women with PMS.
101
women studied
20%
sustained improvement
50%
symptom reduction threshold
About the study
- Original title
- Characteristics of placebo responses in medical treatment of premenstrual syndrome
- Authors
- Freeman EW, Rickels K
- Journal
- The American journal of psychiatry
- Year
- 1999
- Study design
- Randomised trial
- Participants
- 101
- What was tested
- Placebo pills for 3 months in double-blind format
- Read the paper
- doi.org/10.1176/ajp.156.9.1403
Topics
Related studies
Review, 2015
What treatments work best for PMDD and PMS?
Systematic review, 2007
What treatments work for premenstrual syndrome?
Randomised trial, 2004
What medications work for PMDD when taken only during the second half of the menstrual cycle?
Review, 2003
How do menstrual cycle hormones affect the brain and cause mood disorders like PMDD?
Review, 2002
What treatments work best for PMS and PMDD?
Study, 1997
What medications work best for treating PMS?