For women suffering from premenstrual dysphoric disorder (PMDD) — a debilitating form of PMS that affects between 3 and 6 percent of women — and from negative side effects of their anti-depressant medication, Yale Psychiatry professor Kimberly Yonkers is searching for a way to ease their monthly pain.

In a current study run by the Yale PMS, Perinatal and Postpartum Research Program, principal investigator Yonkers is examining the success of a new treatment method for women with PMDD that will only require medication during the symptomatic period each month.

Currently, women who suffer from PMDD typically take daily seratonin inhibitors — such as sertraline, commonly known as Zoloft — to combat the monthly effects of PMDD.

The study, which is currently recruiting participants, aims to determine whether patients experience positive results from the treatment even if they do not take it daily.

In the randomized clinical trial, participants have a 50 percent chance of receiving an active medication and a 50 percent chance of receiving a placebo sugar pill, program coordinator Joanne Cunningham said. It will then track these women for six months to determine whether they experience symptom relief with the new treatment method.

If the alternative plan proves successful, researchers said, the advantages would include lower medication costs for the patient and fewer side effects, which can include dry mouth, sweating, difficulty sleeping, tremor and fatigue.

Obstetrics and gynecology professor Joshua Copel said he thinks the study will be useful in improving understanding of PMDD.

“The hormonal levels in women fluctuate through their cycles,” he said. “Since we don’t know exactly what causes PMDD in individual women, it’s hard to know if it’s sufficient to treat them only when they have symptoms.”

PMDD symptoms include depression, mood swings, irritability, anxiety and suicidal feelings — 15 percent of women with PMDD try to kill themselves at some point. Women with PMDD may also experience physical symptoms like sleep, appetite and energy changes, breast pain and bloating.

Prior work by Yonkers has indicated that treatment for half of the menstrual cycle — about 16 to 18 days — showed results, and that every-day treatment is not the only viable option.

“Recently, people have been trying to push the envelope farther to reduce the amount of time patients need to take medication,” she said. “It hasn’t yet been empirically studied, and doctors like to practice treatments with good proof that they work. It’s our job to find something that women can tolerate and that helps them and that minimizes side effects.”

Participants in the study will be recruited through public postings at places like women’s health fairs, as well as through radio and television, Cunningham said. Active recruiting will continue for four years, and the study is expected to last for five years.

The first group of subjects — currently charting their symptoms — is expected to begin treatment in early to mid-December, Cunningham said.

Yonkers said the primary benefit of the study is that, if results are positive and indicate treatment efficacy, women can minimize their medication intake, which she said is a goal for many patients.

But Dr. Margaret Altemus, a co-principal investigator for this study at Cornell University, said the study might also have larger implications than simply improving treatment for women with PMDD.

“It’s very interesting that women can respond so quickly to the [medication], which indicates that the drug might be working in a different way than our current model,” she said. “Maybe people with other subtypes of depression might respond more quickly to medication, too.”

Although Yonkers was hopeful about the study’s clinical results and possible applications, she did not offer any guesses about the outcome. She said she was wary of predicting results.

“We have to approach these things with a certain degree of skepticism,” she said. “And without having done the research, we can’t say for certain what will happen.”

The center is hoping to enroll 300 women in the study from three sites — Yale, Cornell and Virginia Commonwealth University. Participants must be female, between the ages of 18 and 48, have regular menstrual cycles and suffer from severe clinical PMDD, and they must not currently be on anti-depressants or anti-anxiety medication.