A Preliminary Examination of Maternal Depression In Mothers of Infants at Risk for ASD

Background: Mothers of children with autism spectrum disorders (ASD) tend to show higher levels of depression compared to mothers of typically developing children (Montes & Halterman, 2007). However, little attention has been given to the study of depressive symptoms in mothers of infant siblings of children with ASD. Given that maternal depression is associated with negative maternal outcomes and child outcomes (Cummings & Davies, 1994), including language, cognitive, and social deficits (Brennan et al., 2000), this may be an important covariate to consider when exploring the influences on sibling and mother outcomes. The first step in examining this question is to explore if there are differences in depressive symptoms between mothers of infants at risk for ASD versus mothers of low-risk siblings.

Objectives: 1) To compare the levels of depressive symptoms among mothers of infants at risk and mothers of low-risk infants over time; 2) To examine group differences in the amount of mothers meeting clinically significant criteria for depressive symptoms within each group at each time.   

Methods: As part of a longitudinal study of infant siblings of children with ASD, mothers of infants at risk for ASD (n = 59) and mothers of low-risk infants (n = 32) completed the Center for Epidemiologic Studies Depression Scale  (CES-D; Radloff, 1977) at three different times (infants 12 months, 18 months, and 24 months of age).

Results: A mixed ANOVA was conducted to assess group (n_ASD = 19, n_control = 18) and time (12 months, 18 months, and 24 months of age) differences in levels of maternal depression. Results indicate a significant main effect of group, F (1, 35) = 5.476, p =.025, partial eta² = .135, but not of time, F (2, 70) = .727, p = .487, partial eta² = .02. There was no interaction effect of time and group, F (2, 70) = .423, p = .657, partial eta² = .012.  To further examine the clinical significance of these findings, a chi-square test was used to evaluate whether there are more mothers with clinically elevated depressive symptoms among the siblings at risk versus siblings not at risk groups (n_ASD=59; n_Control=32). These results indicate there is no significant relationship between maternal depression at 12 months and group (x²₁ = 3.67, p = .055, phi = .201), nor at 18 months (x²₁ = 2.375, p = .123, phi = .196), but there is a significant relationship at 24 months (x²₁ = 5.021, p = .025, phi = .342). This indicates that mothers of infant siblings at risk for ASD endorse symptoms of depression significantly more than the control group. 

Conclusions: Results suggest that mothers of infants at risk for ASD are more depressed than mothers of low-risk infant siblings, and this difference became clinically significant as the infants aged. Although the sample size for these analyses is small, the moderate effect sizes indicate that maternal depression may be an important covariate to consider in further studies investigating the well-being of infants at risk for ASD and their mothers.