We examined, in a within-group analysis of mothers of adults with DS, whether artifactual or valid factors account for advantages in well-being. Our findings suggest that it may be problematic to infer, from between-group comparisons, explanations for why a particular group of mothers of individuals with IDD manifest their distinctive profiles of well-being, without checking whether these explanations hold up in within-group studies. Pairing between-group comparative analyses with within-group investigations may yield a stronger understanding of the factors that account for well-being profiles in mothers of individuals with different types of IDD than either analytic approach alone. For the most part, we found that, among mothers of adults with DS, older maternal age and access to social supports were not related to three of our four measures of maternal well-being, even though these factors differentiated such mothers from their counterparts whose children have other types of IDD in past research. However, we found a different pattern of predictors for one measure of maternal well-being, implicating both factors that have been portrayed as artifactual as well as those that are considered to be valid.
Specifically, for the outcomes of life satisfaction, quality of the mother's relationship with her son or daughter with DS, and pessimism, maternal age at birth of her child with DS and social supports were not significant predictors. Instead, the DS behavioral phenotype of having fewer behavior problems was found to contribute the most to better outcomes, net of all other variables. This finding suggests that the DS advantage found for these three maternal outcomes may be valid, not artifactual. It is noteworthy that the aspect of the DS behavioral phenotype that most strongly predicts maternal well-being is not functional abilities, but rather behavior problems. This finding points to the importance of treating behavior problems in adulthood, even among adults with DS.
A different pattern was found with respect to maternal subjective burden. Both variables conceptualized by others as artifacts (older maternal age and greater social support) as well as the DS behavioral phenotype were found to contribute to maternal subjective burden, suggesting that accounting for the DS advantage with respect to subjective burden is more complex than with the other measures of maternal well-being we examined. In addition, several other maternal and child characteristics also had a significant role in predicting this outcome, including maternal marital status, and child age and gender. Widows, mothers of daughters, and mothers of younger adult children felt more burdened. As child and maternal age are strongly correlated in our sample, our findings are consistent with the literature that older mothers commonly report better maternal well-being than younger mothers (Esbensen, Seltzer & Abbeduto, 2008
; Krauss & Seltzer, 1995
). Our finding that mothers of daughters report more burden is novel. A closer examination on an item-level of gender differences in perceived caregiving burden suggests that this finding is driven by maternal feelings of not receiving needed support from family and having to manage multiple roles (family, work). The impact of the gender of the child with DS on maternal well-being warrants further examination. Maternal burden is a role-specific measure of well-being, and thus the specific circumstances of the caregiving context may be more significant than with more general measures.
Our findings also have implications for service provision for adults with DS and their mothers. One of the maternal characteristics that consistently played a role in the present analysis in predicting maternal well-being was maternal health. Sample mothers were in their late 60s, so naturally their own health problems would play a large role in predicting their psychological well-being (life satisfaction and subjective burden). This pattern persisted even when we substituted maternal age for child age in the regression model (data available from the first author). However, maternal health did not play a significant role in predicting the quality of the relationship with her son or daughter. Instead, child health influenced the quality of the mother-child relationship. This finding further underscores the importance of providing quality health care to individuals with DS as they age, as well as to their mothers, as our past research has documented the health declines that accompany advancing age in adults with DS (Esbensen, Seltzer & Krauss, 2008
One limitation of this analysis is that is it based on a sample of mothers of adult
children with DS, taking advantage of a previously collected dataset. We do not know if the same pattern of findings would be observed among mothers of at earlier stages of the life course. It may be that maternal age at the time of her child's birth is a more salient protective factor for mothers of young children than for mothers of adults. On the other hand, theories of cumulative advantage across the life course (Ryff, Singer, Love & Essex, 1998
) would suggest that if maternal age confers an early advantage to mothers of children with DS, this advantage should become magnified over time. Given the longer lifespan of adults with DS and, for many, the concomitant longer period of coresidence with the mother, the persistence of patterns across the full life course is a highly salient issue for research, policy, and provision of services to these families.
In our sample, social support did not contribute to several measures of maternal psychological well-being. However, there are other methods of measuring social support, indicating that our findings warrant replication before the contribution of social support is discounted as being a contributor to the DS advantage (Cohen, Underwood & Gottlieb, 2000
). Other limitations include that the current sample was based on a volunteer, largely Caucasian sample. The current sample also relies on only maternal informants and concurrent measures, which introduces shared method variance to the analyses possibly masking other significant findings. Further, the models accounted for only a portion of the variance in maternal well-being (ranging from 22% to 30%), suggesting that there is much additional research to be conducted to fully understand maternal well-being in the later years of the life course among mothers of individuals with DS.
An additional explanation for the DS advantage is that some of the groups to which mothers of individuals with DS have been compared may themselves bear biological vulnerability to poor well-being outcomes, separate from any reactive effects of parenting. Whereas DS is a sporadic condition, not passed on from the parent to the child, this is not the case for all other IDD conditions. For example, some mothers of individuals with autism spectrum disorders (ASD) are believed to have the broader autism phenotype (Piven, Palmer, Jacobi, Childress & Arndt, 1997
), which may predispose them to higher levels of depression, anxiety, and other indicators of poorer psychological functioning independent of the stressful behaviors of their child with ASD. Similarly, mothers of children with Fragile X Syndrome (FXS) have either the full mutation of FXS or the premutation, both of which have been shown to have mental health comorbidities independent of parenting stress (Seltzer, Abbeduto, Greenberg, Almeida, Hong & Witt, 2009
). It is possible that, as a group, mothers of individuals with DS may have better well-being profiles than mothers of individuals with ASD or FXS in part because of differential biological vulnerability as well as differential levels of parenting stress.
This study contributes to the understanding of the DS advantage. Our findings suggest that a diagnosis of DS confers an “advantage” with respect to maternal well-being, and that this advantage is not merely an artifact. However, depending on the measure of maternal well-being of interest, understanding the DS advantage can be complex, with multiple family and child characteristics also contributing to enhanced maternal well-being. The next step in this line of investigation is to examine what accounts for the DS advantage among mothers of younger children and adolescents. The better we understand what accounts for the DS advantage, the better we will be able to inform and support families of individuals with DS.