Clinical subtypes of core premenstrual disorders: a Delphi survey.

The purpose of this study was to classify the clinical subtypes of core premenstrual disorders during the International Society for Premenstrual Disorders' second consensus meeting. Multiple iterations were used to achieve consensus between a group of experts; these iterations included a two-generational Delphi technique that was preceded and followed by open group discussions. The first round was to generate a list of all potential clinical subtypes, which were subsequently prioritized using a Delphi methodology and then finalised in a final round of open discussion. On a six-point scale, 4 of the 12 potential clinical subtypes had a mean score of ≥5.0 following the second iteration and only 3 of the 4 still had a mean score of ≥5.0 after the third iteration. The final list consisted of these three subtypes and an additional subtype, which was introduced and agreed upon, in the final iteration. There is consensus amongst experts that core premenstrual disorder is divided into three symptom-based subtypes: predominantly physical, predominantly psychological and mixed. A proportion of psychological and mixed subtypes may meet the DSM-IV diagnostic criteria for premenstrual dysphoric disorder.