El que ya no está y ahora es el río

In one of the few studies that have explored the link between insomnia and depression in postpartum women, Dørheim et al. (2009), recruited a sample of 2,830 women who had delivered at Stavanger University Hospital in Norway. At seven weeks postpartum, questionnaires were mailed to women living within the hospital’s

catchment area. Depressive symptoms were measured with the EPDS (Cox et al., 1987) while the PSQI (Buysse et al., 1988) was used to measure maternal global sleep quality. Findings indicated that 17% of women had EPDS scores ≥ 10 (M = 5.30) while 58% (M = 6.30) reported experiencing poor quality sleep (PSQI > 5). A forward multiple logistic regression analysis was conducted to explore factors associated with maternal sleep quality. The analysis indicated that the following factors were significant predictors of maternal sleep problems: depressive symptoms, previous sleep problems, being

primiparious, breastfeeding with supplement and having a male infant. Of these factors, depression, was the most strongly associated with maternal sleep problems (OR = 7.4, 95% CI 5.5-10.0, p < .001). In addition, Dørheim et al. asked participants four questions concerning their sleep history prior to pregnancy, previous difficulty falling asleep, multiple awakenings at night, early morning awakenings and sleep problems affecting daytime functioning. Results indicated that previous sleep problems were associated with poor global sleep quality (OR = 3.4, 95% CI 2.8-4.2, p < .001). The researchers suggested that mothers, with a history of sleep problems, may have more difficulty adjusting to sleep disruption during the postpartum period.

Bei et al. (2010), in a previously described study, also examined the link between sleep quality and mood. Depression was measured subjectively using both the Hospital and Depression Scale (HADS) (Zigmond & Snaith, 1983) and the Depression and Anxiety Stress Scale (DASS) (Lovibond & Lovibond, 1995). Multiple regression analysis indicated that the perception of night sleep, as measured by the PSI (Buysse et al., 1988) during the third trimester was a significant predictor of depression and anxiety (as measured by the HADS) accounting for 27% of the variance in the total HADS score. Third trimester subjective sleep scores were also significantly associated with lower postpartum HADS scores (R2 = .25, p < .05). In contrast, objective measures of night time sleep were not significantly associated with either depression or anxiety during the third trimester or postpartum. The authors suggested that the perception of poor sleep may have a greater impact on mood than actual sleep quality and quantity.

As noted previously the authors of an Australian community study Hiscock & Wake (2001) reported that current maternal sleep quality (assessed by one unidentified item from the PSIQ (Buysse et al., 1988) was predictive of depression according to community (>10) or clinical (>12) cut off scores on the EPDS (Cox et al., 1987). However it is important to note that sleep quality data was only available for 42% of mothers.

The findings from these studies, suggest that mothers who perceived that they had good sleep quality were less likely to report depressive symptoms and that the presence of sleep problems prior to pregnancy, may influence maternal sleep quality during postpartum. It is also possible that postnatal depression may aggravate an already

impaired sleep quality in those women who have a history of unrecognised sleep problems.

Research has linked insomnia and anxiety via a number of different associations (2008). Individuals with insomnia are at increased risk of developing an anxiety

disorder (Neckelmann et al., 2007). The first research to highlight this link was the National Institute of Mental Health Epidemiological Catchment Area study (Ford & Kamerow, 1989). In this population based study, 7,954 adults were interviewed on two occasions one year apart. Results indicated a significant association between insomnia symptoms and anxiety. In a survey of 1,200 adults aged 21 to 30 years, Breslau, Roth, Rosenthal and Andreski (1997) found that the risk of developing an anxiety disorder showed a two-fold increase in individuals who had insomnia three years earlier

compared with those who were good sleepers. In another study, Morphy, Dunn, Lewis, Boardman & Croft (2007) conducted a questionnaire survey in the United Kingdom, using a random sample of 2,662 adults above 18 years of age. Results indicated that participants had a two-fold risk of developing an anxiety disorder if they had reported one sleep problem occurring ‘on most nights’ a year earlier. Other demonstrated links between insomnia and anxiety include higher ratings of trait anxiety in individuals with insomnia than in ‘good’ sleepers. For instance, Fichten, Creti, Amsel, Weinstein and Libman (1995) explored the link between anxiety and sleep in a sample of 634 older adults living in the community. The researchers compared ‘poor’ sleepers who experienced distress and those with similar reported ‘poor’ sleep who experienced no distress. Using the Penn State Worry Questionnaire (PSWQ) (Meyer, Miller, Metzger, & Borkovec, 1990) Fichten et al. reported a significant group difference between poor sleepers with high and low distress with the most distressed poor sleepers being the

most anxious (M = 43.80 vs. M = 56.60, p < .001). Fichten and colleagues claimed that the scores of highly distressed ‘poor’ sleepers reflected an “anxious, depressed,

worrying and negative cognitive-affective set” (p. 214).

Despite these various relationships, the only study found that had examined the link between insomnia and anxiety in postpartum women was the previously described study by Swanson, Pickett, Flynn and Armitage (2011). At intake to the psychiatric outpatient clinic the 114 pregnant and 113 postpartum women (N = 257) completed the following measures: ISI (Bastien et al., 2001), EPDS (Cox et al., 1987), PSWQ (Meyer et al., 1990). The results indicated that, after controlling for depression, there was a significant relationship between generalized anxiety and insomnia for pregnant women, but not for postpartum women. The authors also reported that although the ISI total score was associated with anxiety scores only the ‘difficulty falling asleep’ item of the ISI was a significant predictor of anxiety scores. Limitations of the study acknowledged by the authors were that the PSWQ only measures symptoms of generalised anxiety and neither the ISI nor the PSWQ have been validated in childbearing samples.