It has previously been demonstrated that a single consultation provided in a primary health-care setting can improve infant sleep by up to 14.6 h/week.14
The application of this strategy to families with established sleep problems has demonstrated a clear improvement in infant sleep and importantly, significant improvement in the psychological well-being of mothers. There was a significant reduction in maternal depression, anxiety and stress scores (all p<0.003) following one single sleep behaviour consultation. Importantly, the changes observed reflect a clinically and socially significant improvement in outcome scores. A third of mothers (32.5%) reported at least mild levels of depression at baseline, and at follow-up this figure had decreased to 5%, with similar results for anxiety and stress. Most importantly, the numbers of women in the severe/extremely severe categories at baseline were all reduced at the post-intervention assessment.
Our findings add support to previous studies. Three randomised controlled trials have demonstrated that sleep management programmes can have a beneficial effect on reducing depression prevalence, and improve sleep performance.15–17
Armstrong et al15
implemented an outpatient-based sleep management programme conducted over a longer time frame, and with older children than in the present study. Depression was reduced from 40% of the sample at baseline, to 4.3% at an average of 2 months later. Similarly, this study sample consisted of parents presenting to a sleep clinic and the intervention was the provision of ‘controlled crying’ and ‘cold turkey’ techniques. Significant improvements in sleep parameters also occurred. Controlled crying techniques require the parent to put the baby down awake at sleep times, and allow him to go to sleep with minimal intervention. The infant may cry for a certain time, and if not settled to sleep by this time, parental reassurance is required. This response may involve a check of the infant, a rewrap, or perhaps a short top-up feed, and then returning the infant to attempt to sleep again. This parental response to crying occurs at increasing time intervals.
A larger randomised trial by Hiscock et al16
involved over 300 mothers reporting an infant sleep problem at 7 months of age. The intervention comprised consultations regarding behavioural strategies, the formation of a sleep management plan and handouts on normal sleep patterns. The behavioural intervention consisted of two options: (1) ‘controlled crying’ whereby the parent responded to infant crying at increasing intervals, or (2) ‘camping out’ whereby the parent sat with the infant until they fell asleep, gradually removing their presence over 3 weeks.16
Depression was significantly lower at both 10 and 12 months for the intervention mothers compared with controls, as was the reporting of sleep problems. These improvements appear to have been maintained at 2 years, with intervention mothers having 59% lower odds of reporting depressive symptoms at this time.17
The significant morbidities associated with problems of infant sleep have been reported extensively, particularly postnatal depression. A large meta-analysis of 59 studies, including over 12 000 women and using a range of different assessment methods, estimated that overall prevalence of postpartum depression was 13%.3
Australian studies have reported figures ranging from 6.2%21
with figures increasing to 22.6% when a lower cut-off (for minor depression) is used.23
These studies were all conducted within the first 2 months of the infant's life. Prevalence at longer follow-ups between 5 and 9 months postpartum have shown higher prevalence's of between 13.9% and 16.9% for major depression,24
and 18.2% for minor depression.25
Maternal anxiety, given much less attention than postnatal depression, may also be experienced by a large number of women. Panic attacks or intense anxiety has been reported by up to 15.7% in the first 3 months postpartum, and 8.5% from 6 to 9 months postpartum in Australian mothers.25
Based on the number of registered births in Australia in 2010 (nearly 300 000), and using a prevalence estimate of 15%, a possible 45 000 women per year may experience some degree of postnatal depression, clearly an enormous public health problem. The high rates of maternal anxiety and depression in mothers of infants with sleep problems have been previously demonstrated.2
Assisting these mothers to improve their infant's sleep is therefore a very important factor in reducing depression. An effective behavioural strategy, such as the one presented, implemented by parents in the home environment to significantly improve infant sleep could potentially have a significant impact on reducing the rates of postnatal depression in Australian mothers.
It is well established that the detrimental impacts of postpartum depression extend beyond the parent to the child. Deficits in early interactions and cognitive functioning, insecure infant attachment and behavioural disturbances have been associated with postpartum depression.8
Second, the lack of prolonged sleep itself, can have detrimental effects on child development, including behavioural, cognitive and physical parameters.5
An effective intervention, which can improve sleep behaviour in infants, and subsequently symptoms of depression in mothers, may therefore benefit the mother and the child. This is a simple consultation-based strategy, that is, time effective, and can be readily taught to a healthcare professional in a primary care setting. It has the potential to be an extremely cost-effective means of improving infant sleep and maternal mental health.
Some limitations must be acknowledged. Our recruitment methods relied upon women presenting to a local medical practitioner for assistance. These women had therefore identified a problem and been willing to seek help. Women aged under 20, and of non-English-speaking background were likely to have been unrepresented in the study. Data were not collected on other socio-demographic determinants such as family income, education or relationship status. Without this information or comparative population data, the representativeness of the sample cannot be concluded.
The definition of a sleep problem, in the absence of an accepted form of measurement, was defined according to parental report. However, the collection of the number of nocturnal awakenings confirmed that these infants did have broken sleep. We are unable to define the direction of causality between sleep problems and maternal mental health. The intervention employed in the current study, effective in improving infant sleep behaviour, is concurrently targeting psychological well-being.
Information regarding the number of nocturnal awakenings was not obtained from those women who completed the follow-up by telephone (n=28), which is a shortcoming of the study. Measures of maternal sleep quality and quantity, or other measures of maternal health apart from the psychological measures were not obtained. It also must be acknowledged that it is possible that participants were receiving other treatment or assistance for either their depression or their infant's sleep problems during the study period. A major limitation of the before-and-after study design is the inability to control for other external factors that may impact upon the outcomes. Other external factors that may have impacted upon the results, and that were not measured, include family or social stressors. Subsequently, any cause-and-effect conclusions cannot be drawn. Finally, we cannot determine whether non-respondents to the second questionnaire did not have intervention success and therefore were not willing to complete the questionnaire. Despite these limitations, the findings are suggestive that this behavioural technique may be of benefit to mothers experiencing some degree of postnatal depression, anxiety or stress. The intervention may be quite easily replicated by trained physicians or nurses in other primary healthcare settings, particularly in clinical practices that specialise in infant and maternal health.
Our findings indicate that effectively managing infant sleep problems may be a key component of treating postnatal depression. The intervention promotes the development of good sleep habits by putting the infant to sleep awake and without parental intervention. This behavioural intervention may potentially present as a timely and effective technique for reducing postnatal depression, anxiety and stress in mothers. With the adverse impact that both depression and sleep deprivation have on mother and child, the beneficial implications of this intervention for families are immense. Randomised controlled trials are needed to confirm these positive findings, and to examine the impact of the behavioural intervention on infant sleep performance and maternal health, including psychological outcomes and sleep, in the long term.