| Premenstrual dysphoric disorder (PMDD) is a menstrual-related condition characterized by affective, behavioral, and physical symptomatology resulting in significant functional impairment during the late-luteal (premenstrual) phase of the female reproductive cycle. Women with PMDD have been found to suffer from pain-related symptoms; however, there has been a paucity of well-controlled research assessing pain responsivity in this group. Further, research investigating sex hormone relationships with experimental pain sensitivity in PMDD has been scant. Therefore, the purpose of the study was to assess the relationship between sex hormones and experimental pain processing in women with PMDD and healthy, normally menstruating women. Participants attended testing sessions during the mid-follicular, ovulatory, and late-luteal phases of the menstrual cycle (with order counterbalanced), and salivary estradiol, progesterone, and testosterone were assessed at each testing session. Pain sensitivity was measured from multiple modalities including electrocutaneous threshold, electrocutaneous tolerance, ischemia threshold, ischemia tolerance, and McGill pain questionnaire (MPQ) sensory and affective ratings of electrocutaneous and ischemic stimuli. The current study also used the nociceptive flexion reflex (NFR) as a physiological measure of spinal nociception. Fourteen women with PMDD and 14 healthy women without PMDD completed the study and were included in the analyses; however, an additional sample of 32 healthy women was used in ancillary analyses. While women with PMDD exhibited higher MPQ sensory ratings for electrocutaneous stimuli relative to healthy controls, results revealed there was a lack of group differences for other measures of experimental pain sensitivity. Levels of testosterone were lower in women with PMDD during ovulation, an effect which may be implicated in the development and maintenance of physical and affective symptomatology for the disorder. Results also revealed significant correlations with estradiol and progesterone with measures of electrocutaneous pain tolerance, ischemia threshold, ischemia tolerance, and MPQ electrocutaneous affective ratings for the PMDD group, suggesting these hormones may be anti-nociceptive in this group. Implications of these findings as well as future directions for research are discussed. |
