Up to 46 percent of Australian parents with infants from six to 12 months of age report problems with the infant's sleep, and 10 to 15 percent of Australian mothers with children younger than one year experience significant depression. Infant sleep disorders and maternal depression are linked to long-term adverse effects, such as family disruption, child abuse, childhood behavior problems, and anxiety and depression in family members. Hiscock and Wake studied the efficacy of behavior intervention in reducing infant sleep problems and symptoms of maternal depression.
Infants with sleep problems were identified from May 1998 to April 1999 at community child-health screening clinics in an Australian city. Approximately 80 percent of all children in the community attend these free clinics. Sleep problems were defined as one or more of the following: waking more than five nights per week, waking more than three times per night, needing more than 30 minutes to fall asleep, or requiring a parent's presence to fall asleep. Infants with serious medical or developmental problems were excluded from the study, as were infants who were already receiving help for their sleep problem, mothers who suffered from significant depression, and mothers with insufficient English to complete questionnaires. The researchers randomly assigned 156 mothers to intervention or control groups. The 78 mothers in the control group received only printed information on normal sleep patterns for infants. The 78 mothers in the intervention group each attended three private consultations, during which individualized education and sleep-management plans were developed and reinforced. The principal strategy used was controlled crying, (i.e., parents responded to crying at increasing time intervals, thus allowing the infant to fall asleep). Mothers in the intervention group also received information about normal and abnormal sleeping patterns and were asked to maintain a diary of the infant's sleep. The results of the interventions were assessed at two and four months, using the infant sleep diaries and the Edinburgh postnatal depression scale to assess maternal mood.
At two months, significantly more mothers in the intervention group reported resolution of sleep problems than in the control group (70 percent compared with 47 percent). The remaining sleep problems were less severe in the intervention group, and mothers in this group were less likely to have sought additional help. During the first two months, adjusted depression scores fell significantly lower among mothers in the intervention group than in the control group. In the subgroup of mothers in the intervention group who were initially considered depressed, scores on the Edinburgh depression scale fell by 43 percent during the first two months. After four months, the differences in maternal depression scores between the groups were no longer significant. Sleep disorders had resolved in 64 percent of the intervention group and in 55 percent of the control group by the end of four months, but this difference was not statistically significant.
The authors conclude that controlled crying reduced infant sleep disorders and benefited depressed mothers. The most severely depressed mothers appeared to benefit most from the intervention. The authors encourage other health care providers to introduce similar low-cost interventions for this common problem.