Postpartum depression (PPD) affects at least 10% to 15% of postpartum women, including more than 600,000 American mothers in 2003 alone. Dramatic changes in the hypothalamic-pituitary-adrenal (HPA) system in the transition from pregnancy to postpartum coupled with research on the psychobiology of depression provided the foundation for this study. The purpose of this study was to compare the reactivity and regulation of the HPA axis components, adrenocorticotropic hormone (ACTH) and cortisol, in depressed and nondepressed postpartum women. A comparative, longitudinal study design was used with 22 normal, healthy, nondepressed pregnant women. Physiologic and postpartum depression data were collected at 6 and 12 weeks postpartum at a university clinical research center. Maximal treadmill exercise stimulated plasma ACTH and serum cortisol levels which were measured before, during, and after 20 min of exercise. Postpartum depression was measured with the Postpartum Depression Screening Scale. Lag within-subject ACTH levels predicting cortisol regression slopes were significantly different between the depressed and nondepressed groups at both 6 and 12 weeks. The depressed group showed no relationship between their ACTH and cortisol levels, with higher ACTH and lower cortisol levels when compared with the nondepressed group. The expected regulated relationship with cortisol levels rising in response to rising ACTH levels was found in the non-depressed group. These findings indicate that the HPA axis was dysregulated in the depressed group, but regulated in the nondepressed group at 6 and 12 weeks postpartum. This pattern of higher ACTH levels to stimulate less cortisol is similar to patterns found in women with early life stresses.

Depression is the mental health disorder most commonly seen in the primary health care setting. Estimates of the prevalence of people who are depressed but are seeking treatment for physical disorders in the primary care setting range from 12% to 55% of total patients. We conducted a study to determine the number of women with high depressive symptoms who were seeking treatment for physical disorders and compared this group with women with no depressive symptoms who were also seeking physical health care. The women with high depressive symptoms (n = 122) and the women with no depressive symptoms (n = 115) were similar in age, economic status, occupation status, and lifestyle. The depressed women reported significantly more physical complaints, increased disability, increased functional limitations, and increased use of health care services than did the nondepressed women. They disclosed a variety of physical complaints in all organ systems, had had more life events, and had a diminished belief in their ability to control their environments. The results of this study support the view that large numbers of women with depression that is unrecognized present themselves to the health care system for physical complaints. Health care providers need to extend their view of women as whole beings, instead of as a somatic complaint.

The availability of sufficient zeitgebers is essential for entrainment of circadian rhythms. Bright light is an important human zeitgeber. However, social cues acting through the sleep-wake cycle may also be important in the entrainment of human rhythms. Current research suggests that humans receive inadequate and sporadic exposure to bright light. Social cues, although less powerful, may be an important form of entrainment for contemporary humans, and also serve to augment the effects of available bright light. Both light and social zeitgebers should be investigated for their roles in the genesis, prevention, and treatment of alterations in health.

Body temperature rhythms and diurnal type were explored in female controls and women with seasonal affective disorder (SAD) before and after phototherapy. Women with SAD reported being more like evening types than did controls. Morning phototherapy advanced the body temperature rhythms of women with SAD, and shifted their morningness/eveningness scores toward the morning end of the continuum. The implications of these results for our understanding of both SAD and depression in women are discussed.

The role circadian rhythms play in mental health, sleep, human development and aging, pharmacologic efficacy, immune function, and cardiovascular health makes them a natural focus of nursing research. Integration of chronobiologic concepts into nursing care demands sound empirical support. Nevertheless, issues such as detection of linear trends, the fit of circadian data to a cosinor model and circular distributions, add complexity to the collection, analysis and interpretation of circadian rhythm data. The purpose of this paper is to convey an informed understanding of ways in which to deal with this intricate assembly of issues.