The concept of stress, or the general response o f the body to demands made upon it (Selye, 1956), is a complex one. It is possible that the environment may effect
the experience o f the menstrual cycle in a variety o f ways: F or example, Golub (1992) observes that stressful events, by eliciting a change in hypothalamic functioning, can disrupt the course of the menstrual cycle. U ssher (1987) points out that the precise rela tionship between stress and m e n stru a tio n , w hether menstruation acts as a stressor or whether women are more vulnerable to stress at p articu la r points in the ir menstrual cycle, is far from clear. Sommer (1978) suggests that stress may be conceptualised as both a response and a stimulus in m enstru al cycle research, m enstrual cycle related sym ptom s proving to be internal sources o f stress, and en v ironm ental stresses (s tim u li) and phasic re s p o n se ex tern al.
The cognitive appraisal o f the stressor is, as noted previously, important in d eterm ining the response given. K o e s k e ’s (1977) research on attitudes and expectations towards the menstrual cycle suggests that women with PMS have m ore negative attitudes to menstruation, and may evaluate their premenstrual ex p e rien ce differe n tly from n on-sufferers.
Beck et al (1990) recruited a sample of 25 women seeking help for PMS, to investigate the predictive role of psychosocial stress on symptom severity. All participants had prospectively confirm ed PMS, and were from a self-selected (volunteer) sample. Participants were studied prospectively for three consecutive m enstrual cycles. Inform ation was collected on daily stress, mood (using the Bond-Lader mood scale: Bond & Lader, 1974), and physical symptoms. Stress was found to account for only 6% and 10% o f the unique variance in mood and physical symptoms across the menstrual cycle. Furtherm ore, no association was found between the severity o f symptoms and daily stress. The authors conclude that for this sample of women, psychosocial stress could not be used as a predictor for PMS symptom severity.
T he relationship between stress and PMS is not, then, clear. Koeske (1977) rep o rte d an in c re a s e in n eg ativ e moods and p re m e n stru a l sym ptom s with increased stress. Woods (1985) found that exposure to a stressful environm ent helped to explain cyclical symptoms of negative affect, but had no effect on
physiological premenstrual symptoms.
If we conceptualise menstruation as a stressor (Jensen, 1982) , then coping and coping strategies become a central concern. Coping strategies may be defined as any cognitive response that reduces arousal (Lazarus, 1978), and obviously social factors such as learned behaviour and expectations may play a significant part in a w om an’s coping ability. Choi & Salmon’s (1995) study o f how women cope with menstrual cycle changes suggests that not only do most women employ an active cognitive style of coping, but that this is most effective. It would be interesting to follow up this study by examining differences in coping skills employed by PMS sufferers compared to a group of non-PMS women, using the same checklist.
Certainly, there is evidence that w om en’s responses to the menstrual cyele, and the menstrual cycle itself, may be affected by changes in environm ental stress (see Ussher, 1987 for a review). For example, Marinari et al (1976) found elevated levels of plasma cortisol in women who were exposed to a stressor premenstrually, com pared to m id-cycle readings, and these d ifferences were not observed in contraceptive pill users, suggesting an hormonal cause. However, Abplanalp et al (1977) failed to replicate these findings.
It is possible that w om en’s vulnerability, or responsivity, to stress varies across the menstrual cycle. Strauss et al (1983), however, found no menstrual cycle effect on stress reactivity measured by electroderm al responses and self report. Hastrup & Light (1984) reported that subjects tested in the follicular phase of the cycle showed less of a stress response, measured by heart rate and blood pressure, than subjects tested in the luteal phase.
U ssher (1992a) suggests that one explanation for the relationship between stress and the menstrual cycle to be that some additive effect exists, where external stressors (such as negative life events) lead to negative affect when combined with an u n d erly in g increased sensitivity. In o th e r words, that physiological arousal may change across the menstrual cycle, and that this may mediate stress response and prem enstrual experience.
Ussher & Wilding (1992) employed a battery o f measures to asses and manipulate stress levels, arousal and activation, personality and perform ance in a group of
self-reported PMS sufferers, and a group of non-PMS controls, at discrete points in the menstrual cycle. No differences were found between the PMS and non-PMS particip a n ts in reactions to stress, how ever all p articipants reported increased levels o f stress and arousal premenstrually, with this increase being significantly greater in the PMS group. The PMS group did, however, have a significantly higher score on the neuroticism scale of the EPI than the control, suggesting that perhaps trait factors may be significant in determining a w o m an ’s experience of her menstrual cycle, as well as external events, and subsequent coping skills.
Jensen (1982) and Ussher & Wilding (1991) have suggested that the menstrual c y cle be investigated from within a stress-rese arch fram ew ork, which would predict that any variations in performance over the menstrual cycle would be task and metric specific, because of the non-uniform relationship between state and perform ance (Ussher and Wilding, 1991, 1992). Some research has found differences in response to stress across the menstrual cycle (see Marinari et al,
1976; Hastrup & Light, 1984), and it has been suggested that some women may be m ore vulnerable to p articular stressors prem enstrually (Asso, 1987; U ssher & Wilding, 1992). Therefore baseline measures of stress and arousal are of interest, as well as a stress-research type paradigm, looking for differences in stress and arousal after completion of a stressful task.
It is feasible then that measures of stress, and reaction to stressors, may be used to attempt to distinguish between PMS and non-PMS women. It is also possible that the finding of a relationship between stress and PMS may depend upon the sample under investigation, and the measures used. The relationship between stress and arousal needs further investigation within this context.