Emotional and behavioral functioning of typically-developing sisters of children with autism spectrum disorder: The roles of ASD severity, parental stress, and marital status

Research in Autism Spectrum Disorders 32 (2016) 130–142

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Emotional and behavioral functioning of typically-developing sisters of children with autism spectrum disorder: The roles of ASD severity, parental stress, and marital status Theodore S. Tomenya[140_TD$IF] ,* , Lorien K. Bakera , Tammy D. Barryb , Sophia W. Eldreda , James A. Rankina a b

The University of Alabama, Department of Psychology, Box 870348, Tuscaloosa, AL, 35487, USA Washington State University, Department of Psychology, Pullman, WA, 99164, USA

A R T I C L E I N F O

A B S T R A C T

Article history: Received 9 April 2016 Received in revised form 25 September 2016 Accepted 26 September 2016 Number of reviews completed is 2 Available online xxx

Background: Research has shown varied outcomes for typically-developing (TD) siblings of children with autism spectrum disorder (ASD), suggesting that some emotional and behavioral difficulties may occur only under specific conditions. In addition to characteristics of the children with ASD, family contextual factors may also predict sibling adjustment. Method: This study examined parent marital status and parental stress as moderators of the relation between ASD siblings’ symptom severity and emotional and behavioral adjustment in 56 TD sisters via self- and parent-report. Results: At moderate and high levels of parental stress, TD sisters with siblings with relatively severe ASD symptomatology and with unmarried parents reported the highest levels of emotional and behavioral difficulties. Yet, TD sisters with siblings with relatively less severe ASD symptomatology and with unmarried parents reported the lowest levels of challenging behaviors and emotional symptoms. Conclusions: These findings indicate that clinicians treating families of children with relatively severe ASD and unmarried parents should be particularly cognizant of the functioning of TD sisters. ã 2016 Elsevier Ltd. All rights reserved.

Keywords: Autism spectrum disorder Sisters Siblings Marital status Parental stress

1. Introduction Because of the unique social and behavioral symptoms of autism spectrum disorder (ASD), the effects of ASD are thought to extend beyond those diagnosed to also impact their family members. Researchers have found that ASD’s challenges result in higher levels of stress and more psychological difficulties among family members of children with ASD compared to families with children who have other disabilities (e.g., Constantino et al., 2006; Fisman, Wolf, Ellison, & Freeman, 2000). Additionally, although genetic and environmental influences are important parts of any child’s development, these factors may be of particular importance in typically-developing (TD) siblings of individuals with ASD. Researchers have found that genetic factors are important contributors to the development of ASD (e.g., Tick, Bolton, Happé, Rutter, & Rijsdijk, 2016), as

* Corresponding author. E-mail addresses: [email protected] (T.S. Tomeny), [email protected] (L.K. Baker), [email protected] (T.D. Barry), [email protected] (S.W. Eldred), [email protected] (J.A. Rankin). http://dx.doi.org/10.1016/j.rasd.2016.09.008 1750-9467/ã 2016 Elsevier Ltd. All rights reserved.

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well as the development of more mild, subclinical traits and behaviors consistent with ASD known as the broader autism phenotype (BAP; Bolton et al., 1994). These subclinical traits, which are significantly more common among first-degree relatives of individuals with ASD (e.g., Kadak, Demirl, Yavuz & Demir, 2014; Kose et al., 2013), can include language and communication impairments (Losh & Piven, 2007; Whitehouse, Coon, Miller, Salisbury & Bishop, 2010), difficulties with facial recognition and emotion recognition (Dawson et al., 2005; Ingersoll, 2010), and social difficulties and rigidity (Losh & Piven, 2007; Wainer, Block, Donnellan, & Ingersoll, 2013). These genetic factors, coupled with environmental influences such as altered family functioning and parental mental health challenges, may relate to emotional and behavioral difficulties among TD siblings of individuals with ASD (e.g., Davis & Carter, 2008; Lardieri, Blacher, & Swanson, 2000). However, research has found that outcomes for these TD siblings are highly variable (e.g., Meadan, Stoner, & Angell, 2010; Orsmond & Seltzer, 2007). 2. Sibling relationships, outcomes, and gender differences As the prevalence of ASD has increased, more research has examined the emotional and psychosocial adjustment of their typically-developing (TD) siblings. Some studies have reported that TD siblings of children with ASD experience more emotional and behavioral problems compared to siblings of TD children or children with other disabilities (e.g., Griffith, Hastings, & Petalas, 2014; Ross & Cuskelly, 2006), whereas others have reported no evidence of higher levels of emotional and behavioral difficulties in TD siblings of children with ASD (e.g., Hastings, 2003; Hastings & Petalas, 2014; Tomeny, Barry, & Bader, 2012; Walton & Ingersoll, 2015) or even positive outcomes, such as a more positive self-concept, among TD siblings of children with ASD (e.g., Macks & Reeve, 2007). Recognizing the variability in outcomes of TD siblings of children with ASD, researchers have called for studies focused on identifying risk and protective factors that may influence sibling adjustment (Meadan et al., 2010; Orsmond & Seltzer, 2007). Research indicates that demographic factors such as gender and birth order, as well as diagnostic factors such as symptom severity of the sibling with ASD, may influence the emotional and psychosocial adjustment of TD siblings (Macks & Reeve, 2007; Meyer, Ingersoll, & Hambrick, 2011; Orsmond & Seltzer, 2009; Tomeny, Barry, & Bader, 2014). Although, studies examining these demographic correlates remain mixed and inconclusive, several studies have found that outcomes for TD sisters differ from those for TD brothers. For example, in a 2009 study, Orsmond and Seltzer examined a diathesis-stress model of well-being for TD brothers and sisters of individuals with ASD. This diathesis-stress model accounted for both the genetic vulnerabilities (i.e., BAP characteristics in TD siblings; family history of ASD), and the family and environmental stress to siblings (i.e., behavioral problems in siblings with ASD; sibling life events; maternal depressive symptoms). Similar to previous research showing increased rates among females in general (e.g., Parker & Brotchie, 2004), Orsmond and Seltzer (2009) found that TD sisters of individuals with ASD reported higher levels of depressive and anxiety symptoms than TD brothers. The majority of siblings who plan to co-reside with and care for their siblings with developmental disabilities later in life tend to be sisters (Krauss, Seltzer, Gordon, & Friedman, 1996). Moreover, other research indicates that, on average, TD sisters feel they assume more caregiving responsibilities (Cridland, Jones, Caputi, & Magee, 2015), provide higher levels of support (Orsmond & Seltzer, 2000), and expect to be the primary sources of future care and support for their sibling with a disability (Burke, Taylor, Urbano, & Hodapp, 2012). Some suggest that this imbalance in care provision may be due, at least in part, to sociocultural pressures for women to care for family members in need (McGraw & Walker, 2007). It has been suggested that this increased caregiving responsibility placed on sisters compared to brothers likely begins at an early age (Floyd, Purcell, Richardson, & Kupersmidt, 2009). Despite this caregiving role and the assumed burden, many adult sisters report positive feelings and close relationships with their sibling with a disability (Orsmond & Seltzer, 2000). Taken together, these results suggest that the experience of TD sisters of individuals with disabilities may differ from that of TD brothers. Furthermore, the wide variability in sibling research findings indicates a need to identify the circumstances that predict different outcomes, and this need is particularly important for sisters given their complex roles within families. In addition, symptom severity in the sibling with ASD has been found to be positively related to adjustment difficulties in the TD siblings (Meyer et al., 2011), indicating that symptom severity in siblings with ASD may be another important factor to consider when examining the outcomes of TD sisters. As such, a goal of the current study was to identify demographic and diagnostic conditions under which TD sisters of children with ASD may experience better or worse emotional and behavioral adjustment. Although most studies examining sibling risk and protective factors have used parent report (e.g., [142_TD$IF]Hastings, 2003; Meyer et al., 2011;[143_TD$IF] Shivers, Deisenroth, & Taylor, 2013), others have used sibling self-reports (e.g., Hastings & Petalas, 2014) to examine factors such as TD siblings’ emotional and behavioral problems or their relationships with their siblings with ASD. However, limited studies examining TD siblings’ psychological functioning have utilized multi-informant reports (e.g., [14_TD$IF] Meadan et al., 2010; Rodgers et al., 2016), despite urges from experts to utilize this methodology when assessing youth behavior (De Los Reyes & Kazdin, 2004; Kraemer et al., 2003; Stratis & Lecavalier, 2015). By using multiple reports, researchers achieve better specificity—as well as sensitivity—leading to a more accurate assessment of an individual’s behavior (Goodman, Ford, Simmons, Gatward, & Meltzer, 2000). Thus, we contend that sole reliance on parent report provides an incomplete view of sibling experiences and may add to the variability of research outcomes. We hope to expand upon past findings by examining sibling functioning within the family context that considers the influence of parental marital status and parental stress levels from both parent and TD sister perspectives.

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3. Parental stress Many studies illustrate that parents of youth with ASD experience substantial stress levels (Davis & Carter, 2008; Fisman et al., 2000; Guralnick, Hammond, Neville, & Connor, 2008), even when compared to parents of youth with other conditions (e.g., Hayes & Watson, 2013; Mugno, Ruta, D’Arrigo, & Mazzone, 2007; Olsson & Hwang, 2001). Close to forty percent of mothers and close to thirty percent of fathers of children with ASD may experience clinically significant stress (Davis & Carter, 2008). Parental stress in this population may be related to children’s ASD symptoms (Davis & Carter, 2008), behavior problems (Hastings & Brown 2002), and concerns over the child’s future (Meirsschaut, Roeyers, & Warreyn 2010). Generally, parenting stress is related to numerous adverse physical (e.g., heart attack risk) and psychological (e.g., depression) outcomes for parents (Johnson, Frenn, Feetham, & Simpson, 2011) and may impact the parents’ marital relationships (Hartley, Mihaila, Otalora-Fadner, & Bussanich, 2014). Also, it has been posited that stressed parents are, on average, less able to regulate their emotions and model appropriate behavior, and any negative effects of these less than ideal parenting practices may be felt by TD siblings (Fisman et al., 2000; Pilowsky, Yirmiya, Doppelt, Gross-Tsur, & Shalev, 2004). For instance, TD siblings of youth with ASD who have highly stressed parents are more likely to show delays in the development of their socialization skills (Pilowsky et al., 2004) and may exhibit greater behavior problems (Fisman et al., 2000). Thus, parental stress is likely an important predictor of TD sibling adjustment and outcomes. 4. Marital status As previously mentioned, the quality of marital relationships of parents of youth with ASD may be affected by parental stress (e.g., Hartley et al., 2014). Saini et al. (2015) concluded that parenting stress among parents of children with ASD was a contributing factor in the development and maintenance of poorer marital relationships, similar to that also found in the general population (e.g., Neff & Karney, 2009). One theory is that the psychological and physical fatigue associated with parental stress greatly diminishes parents’ cognitive resources to effectively mitigate negative perceptions of their marital relationship (Baumeister, 2002) and to cope with hardships faced in this relationship (Neff & Karney, 2009). Likewise, marital quality and marital conflict have been associated with poorer adjustment in TD siblings of children with ASD (Dyson, Edgar, & Crnic, 1989). Wieland and Baker (2010) suggest that TD youth may be more attentive to the emotional climate of the home setting and may notice social cues indicative of marital conflict and dissatisfaction better than youth with developmental disabilities. Thus, marital status may hold relatively greater effects on the outcomes of TD siblings. Whereas marital satisfaction, conflict, and quality have been explored in relation to family functioning and child psychosocial outcomes in families affected by ASD (Gau et al., 2012; Hartley, Barker, Baker, Seltzer, & Greenberg, 2012), less attention has been geared toward marital status as a predictor of child outcomes. Because spouses are the primary source of support for each other (Belsky, 1984), the availability of support in caregiving may be significantly reduced in single-parent families. Moreover, findings throughout the ASD literature suggest fathers and mothers of children with ASD have differing impacts on each child’s development (e.g., Davis & Carter, 2008; Hartley, Barker, Seltzer, Greenberg, & Floyd, 2011; Kayfitz, Gragg, & Orr, 2010). Flippin and Crais (2011) illustrated how mothers and fathers’ unique interaction styles with TD siblings contributed to their language and symbolic play. Furthermore, greater involvement of a second parent is related to better outcomes in the primary caregiving parent as well as reductions in the impact of illnesses or disability on family functioning (Gavin & Wysocki, 2006). Thus, it follows that TD siblings within single-parent households may be deprived of the benefits associated with having multiple parents present. Generally speaking, children with divorced parents score lower on measures of academic achievement, appropriate conduct, psychological adjustment, self-concept, and social relations (Amato, 2001). Taken together, these findings suggest that examination of the role of marital status in TD siblings’ emotional and behavioral adjustment may be of particular salience in this population. 5. Purpose and hypotheses Due to inconclusive findings and the need to further address possible risk/protective factors for TD sisters of siblings with ASD (e.g., Meadan et al., 2010; Orsmond & Seltzer, 2007), the purpose of the current study was to examine parental stress levels and marital status as moderators of the relation between ASD siblings’ symptom severity and TD sisters’ emotional and behavioral functioning. Based on previous literature, it was thought that the combination of specific family factors (i.e., having a single parent with higher stress levels and a sibling with more severe ASD symptoms) may be particularly predictive of negative outcomes in TD sisters. It was hypothesized that parental stress and marital status would separately moderate the relations between ASD siblings’ symptom severity and both parent- and self-reported TD sisters’ psychological adjustment. Specifically, we expected that the relation between symptom severity and greater emotional and behavioral difficulties among TD sisters would be strengthened under conditions of higher parental stress. Likewise, we predicted that the unmarried condition would also strengthen the relation between symptom severity and poorer adjustment among TD sisters. As a research question, we also examined whether a three-way interaction between symptom severity, marital status, and parental stress would account for significant variance in TD sisters’ emotional and behavioral adjustment.

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6. Method 6.1. Participants The current study’s participants were drawn from a larger sample of families that included both TD sisters and TD brothers of children with ASD. This sample included 56 TD sisters (ages 11–17 years; M = 13.21, SD = 1.93) of children with ASD (ages 5–17 years; M = 12.09, SD = 3.16; 71% male) and one parent of each sibling dyad (ages 31–60 years; M = 44.63, SD = 5.53; 98% female). The average age difference between siblings was 2.4 years, and 69.6% of TD sisters were older than their sibling with ASD. Each child with ASD was independently diagnosed with autism spectrum disorder as confirmed by parents on the demographic and diagnostic questionnaire (51.8% autistic disorder, 21.4% Asperger’s disorder, and 26.8% pervasive developmental disorder, not otherwise specified). TD sisters were required to be fully-biologically related and living in the same household. Sibling dyads were 84% Caucasian, 3.6% African-American, 3.6% Hispanic, and 8.9% other. Thirty four percent of parents reported a total family income over $100,000, and 64% of parents reported having at least a college degree. Parents were 67.9% married, 26.8% divorced, 3.6% separated, and 1.8% never married/living alone. Marital status was treated as a dichotomous variable (coded 0 = separated, divorced or never married/living alone, 1 = married). 6.2. Measures 6.2.1. Demographic and diagnostic questionnaire Parents completed a questionnaire that included extensive information to confirm a diagnosis of ASD for one child in the family, including diagnostic classification, age of diagnosis, profession and affiliation of person making diagnosis (i.e., to ruleout parents merely self-reporting that they think the child has the diagnosis). The questionnaire also included demographic information about themselves, the child with ASD, and the TD sister. In particular, parents reported their marital status (e.g., married, separated, divorced, never married/living alone) via this questionnaire. 6.2.2. Children’s social behavior questionnaire (CSBQ, Luteijn, Luteijn, Jackson, Volkmar, & Minderaa, 2000) On this 49-item measure of autism symptom severity, parents rated their child with ASD using a 3-point Likert scale with 0 being it does not describe the child, 1 being infrequently describes the child, and 2 being clearly applies to the child (Luteijn et al., 2000). Scores load onto 6 scales: “Behavior/emotions not optimally tuned to the social situation/aggressive behavior” (a = 0.90, ICC = 0.89, r = [145_TD$IF]0.89); “Reduced contact and social interest/withdrawn” (a = 0.85, ICC = 0.79, r = 0.88); “Difficulties in understanding social information” (a = 0.85, ICC = 0.87, r = 0.80); “Orientation problems in time, place, or activity” (a = 0.84, ICC = 0.81, r = 0.82); “Stereotyped behavior” (a = 0.76, ICC = 0.75, r = 0.80); and “Fear of and resistance to changes” (a = 0.85, ICC = 0.80, r = 0.83; Hartman, Luteijn, Serra, & Mideraa, 2006). The CSBQ Total score served as the measure of symptom severity. The CSBQ is a frequently used measure of ASD symptoms (e.g., Kiely, Migdal, Vettam, & Adesman, 2016; Nijmeijer et al., 2014), and it has been well validated against other common ASD assessment tools (e.g., the Autism Diagnostic Observation Schedule, the Autism Diagnostic Interview-Revised, the Autism Behavior Checklist; de Bildt et al., 2009, 2005). Internal consistency was a = 0.91 in the current sample. 6.2.3. Strengths and difficulties questionnaire (SDQ; Goodman, 1997) This 30-item measure assesses child behavioral and emotional functioning. Parents completed an SDQ about the TD sister, and TD sisters completed a self-report version. Respondents rated their agreement with statements as 0-Not True, 1Somewhat True, and 2-Certainly True. Scores load onto five scales: Emotional Symptoms (e.g., often worries, often unhappy), Conduct Problems (loses temper, often fights or bullies), Hyperactivity (e.g., restless, fidgety or squirmy), Peer Problems (e.g., prefers to be alone), and Prosocial (e.g., considerate of others, helpful). Moreover, the sum of the four problems scales generates a Total Problems scale, with total scores ranging from 0 to 40 (a = 0.82; Goodman, 1997). The Total Problems scale from each informant was of interest as general measures of parent- and self-reported behavioral and emotional functioning. The current sample yielded Cronbach’s alphas of 0.85 for parent-report and 0.81 for self-report for the Total Problems scale. 6.2.4. Questionnaire on resources and stress-short form (QRS-F; Friedrich, Greenberg, & Crnic, 1983) This 52-item abbreviated measure assesses self-reported parental stress, adaptation, and coping related to raising a child with developmental delays and other disabilities. Consistent with previous research involving families of children with ASD (Honey, Hastings, & McConachie, 2005), the Parent and Family Problems and Pessimism scales were used to create a composite measure (by summing the z-scores of both scales) of parental stress related to rearing a child with special needs. Internal consistency was a = 0.83 in the current sample. 6.3. Procedure Following approval from the University Institutional Review Board, parents of children with ASD and a TD sibling were recruited via emails to listservs for autism support groups, contacts in research databases, and a referral sampling technique. Parents who agreed to participate were emailed detailed instructions for completing questionnaires and a link to a secure survey website via Qualtrics (Qualtrics, Provo UT, 2005,[146_TD$IF] 2016) through which study questionnaires were completed. As part

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of a larger study, parents who consented completed the demographic and diagnostic questionnaire, the CSBQ on their child with ASD, the SDQ on the TD sister, and the QRS-F on themselves. Following parental consent and their own assent, TD sisters completed the self-report version of the SDQ. Participants could choose to exit the survey and discontinue the study at any time, but only participants who completed all measures remained in the sample. Following study completion, participating families were entered into a random drawing for one of ten $30 gift cards from a national retailer. 7. Results 7.1. Preliminary analyses Less than 0.4% of data were missing at the item level across measures; the relevant scales were prorated and person mean imputation was used per Hawthorne and Elliot (2005) and Roth, Switzer, and Switzer (1999). Descriptive statistics and interrelations of the variables of interest are in Table 1. An examination of the relations of the criterion variables with the predictor and moderator variables shows that siblings’ symptom severity was significantly positively related to parental stress and both parent- and self-reported TD sisters’ emotional and behavioral difficulties (the latter two were also significantly positively correlated). Marital status (coded as 0 = separated, divorced or never married/living alone and 1 = married) was negatively correlated with parental stress such that single parents reported higher levels of parental stress. Parental stress was not significantly related to TD sisters’ emotional and behavioral difficulties (either informant). Correlations between parent-report and TD sister self-report for each of the SDQ subscales suggested moderate congruence: r = 0.52, p <0.001 for Emotional Symptoms, r = 0.42, p = 0.001 for Conduct Problems, r = [147_TD$IF]0.39, p = 0.003 for Hyperactivity, and r = 0.60, p < 0.001 for Peer Problems. Due to concerns about multicollinearity among the predictors, variance inflation factors were examined and determined to be within acceptable limits (i.e., below 2). The relations between demographic variables and the variables of interest are presented in Table 2. Birth order rank of siblings with ASD (higher value representing later birth order) was positively related to siblings’ symptom severity. Moreover, parental stress was positively related to TD sister age. Also, family income was negatively correlated with parentreported TD sister emotional and behavioral difficulties, ASD symptom severity, and parental stress and positively correlated with marital status (married parents reported higher family income). As such, birth order rank and family income were included as covariates in each analysis, and TD sister age was a covariate in analyses examining parental stress. 7.2. Hypothesis testing The moderating effects of parental stress and marital status (as separate moderators) on the relations between siblings’ symptom severity and parent- and self-reported TD sisters’ emotional and behavioral difficulties (as separate criterion variables) were examined via four moderated multiple regression analyses (Table 3). Moderator and predictor variables were centered prior to creating the interaction terms to reduce multicollinearity and aid in interpreting post-hoc plots of significant interactions. When examining parental stress as a potential moderator of the relation between siblings’ ASD symptom severity and TD sisters’ emotional and behavioral difficulties (both informants), Model 1 (control variables) was only significant when predicting parent-reported emotional and behavioral difficulties—with family income accounting for unique variance, B =
1.17, SE = 0.42. p = 0.007. The overall variance increase in Model 2 (main effects) was nonsignificant when predicting self-reported emotional and behavioral problems but was significant when predicting parent-reported emotional and behavioral problems. Specifically, symptom severity accounted for unique variance, B = 0.19, SE = 0.06, p = 0.001. However, parental stress did not emerge as a moderator of the relation between siblings’ symptom severity and TD sister emotional and behavioral difficulties for either informant. Table 1 Intercorrelations and Descriptive Statistics of Variables of Interest.

1. ASD symptom severity 2. Marital statusa 3. Parental stress 4. Parent-report E&B difficulties 5. Sister self-report E&B difficulties Mean SD Skew Minimum Maximum

1.

2.

3.

4.

5.

–


0.26 –

.58***
0.28* –

.45**
0.18 0.12 –

44.27 15.85
0.17 2.00 83.00

0.68 0.47
0.79 0.00 1.00


0.21 1.95
0.26
4.09 3.13

7.12 5.79 0.79 0.00 21.00

.34*
0.05 0.14 0.58*** – 10.60 5.77 0.28 0.00 25.00

Note: ASD = autism spectrum disorder; E&B = emotional and behavioral; SD = standard deviation. a Coded as 0 = separated, divorced or never married/living alone and 1 = married. * p < 0.05. ** p < 0.01. *** p < 0.001.

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Table 2 Correlation between Demographic Variables and Variables of Interest.

Age of Child with ASD Gender of Child with ASDa Birth Order of Child w/ ASD Age of TD Sister Birth Order of TD Sister Race of TD Sisterb Gender Match/Mismatchc Age Discrepancyd Family Income

TD Sister E&B Difficulties (Parentreport)

TD Sister E&B Difficulties (Selfreport)

ASD Symptom Severity

Marital Parental Status Stress

0.18 0.07 0.09

0.23
0.04 0.13

0.03 0.03 .28*


0.07
0.16
0.04

0.11 0.06 0.05

0.18 0.11 0.20 0.07
0.18
0.38**

0.15 0.21 0.13
0.04
0.08
0.20

0.13 0.19 0.04 0.03 0.14
0.39**

0.06
0.11 0.01
0.16 0.13 .53***

0.27*
0.10
0.12 0.06 0.06
0.28*

Note: ASD = autism spectrum disorder; E&B = emotional and behavioral. a Coded 0 = male, 1 = female. b Coded 0 = nonwhite, 1 = white. c Coded 0 = gender mismatch, 1 = gender match. d Absolute value of the age difference between the child with ASD and the TD sister. * p < 0.05. ** p < 0.01. *** p < 0.001.

Table 3 ASD Symptom Severity by Parental Stress and ASD Symptom Severity by Marital Status Predicting Parent- and Self-Reported Typically-Developing Sisters’ Emotional and Behavioral Difficulties. Predictor Variables

Criterion Variables Parent-Reported E&B Difficulties

Self-Reported E&B Difficulties

Parental Stress as a Moderator Model 1 Birth order of child with ASD TD sister age Family income R2


0.25 (0.75) .38 (0.38)
1.17** (0.42) 0.17*

0.39 (0.79) 0.38 (0.41)
0.48 (0.45) 0.06

Model 2 Parental stress ASD symptom severity DR2


0.88y (0.44) .19** (0.06) .16**


0.36 (0.50) 0.13* (0.06) 0.08

Model 3 Parental stress X ASD symptom severity DR2


0.02 (.02) 0.007


0.03 (.03) 0.03

Model 1 Birth order of child with ASD Family income R2


0.28 (0.75)
1.24**(0.42) 0.15*

0.36 (0.79)
0.55 (0.44) 0.04

Model 2 Marital status ASD symptom severity DR2

1.06 (1.78) 0.14** (0.05) 0.12*

1.26 (1.93) 0.11* (0.05) 0.08y

Model 3 Marital status X ASD symptom severity DR2


0.32** (.11) 0.10**


0.30* (0.12) 0.09*

Marital Status as a Moderator

Note: Unstandardized regression coefficients reported for each predictor with standard errors in parentheses; E&B = emotional and behavioral; ASD = autism spectrum disorder; marital status coded, 0 = separated, divorced or never married/living alone, 1 = married. y p < 0.10.

When examining marital status as a potential moderator of the relation between siblings’ symptom severity and TD sisters’ emotional and behavioral difficulties (both informants), Model 1 (control variables) was only significant when predicting parent-reported emotional and behavioral difficulties in TD sisters—again, with family income accounting for

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unique variance, B =
1.24, SE = 0.42, p = 0.004. The variance increase in Model 2 (main effects) was also significant for parentreported emotional and behavioral problems among TD sisters. Specifically, symptom severity accounted for unique variance, B = 0.14, SE = 0.05, p = 0.01. Model 3 (interaction) accounted for a significant amount of additional variance for both parent-reported, B =
0.32, SE = 0.11, p = 0.006, and self-reported, B =
0.30, SE = 0.12, p = 0.02, emotional and behavioral difficulties. In single-parent homes, ASD symptom severity was positively related to TD sister emotional and behavioral difficulties, B = 0.40, SE = 0.10, t(50) = 3.95, p < 0.001 (for parent-report) and B = 0.36, SE = 0.11, t(50) = 3.18, p = 0.003 (for selfreport), whereas, for both informants, these variables did not relate when parents were married. Post-hoc plots of the interactions indicated that emotional and behavioral problems were highest among TD sisters who had a sibling with more severe ASD and who were members of single-parent households (Fig. 1, panels A & B). Additionally, sisters who reported the lowest levels of emotional and behavioral difficulties were also members of single-parent households but had a sibling with milder ASD symptoms. All four moderated multiple regression analyses were repeated without covariates, and the overall pattern of results remained the same. 7.3. Research question testing To test the research question, a three-way interaction term was created (ASD symptom severity X marital status X parental stress) and examined via two moderated multiple regression analyses (one for each informant of TD sisters’ emotional and behavioral difficulties; Table 4). Addition of the three-way interaction term did not account for additional variance in TD sisters’ emotional and behavioral difficulties for parent-report but did for self-report, B =
0.22, SE = 0.09, p = 0.02. Post-hoc plots to interpret the interaction revealed that marital status moderated the relation between symptom severity and TD sisters’ emotional and behavioral problems only under conditions of moderate and high levels of parental stress (Fig. 2). In other words, ASD symptom severity was only related to TD sister emotional and behavioral difficulties in single-parent homes at moderate, B = 0.31, SE = 0.11, t(45) = 2.72, p = 0.01, and high, B = 0.62, SE = 0.18, t(45) = 3.49, p = 0.001, levels of parental stress. A pattern similar to the aforementioned two-way interactions emerged, yet the moderating effects of marital status was most pronounced when parental stress was high (see Fig. 2, panel C). 8. Discussion This study sought to examine family contextual correlates of emotional and psychological adjustment among TD sisters of children with ASD. We predicted that the relations between siblings’ symptom severity and TD sisters’ emotional and behavioral difficulties would be moderated by parental stress and parental marital status, separately. We also explored a three-way interaction between siblings’ ASD symptom severity, parental stress, and parental marital status when predicting

[(Fig._1)TD$IG]

Fig. 1. Interactions between autism spectrum disorder (ASD) symptom severity and marital status predicting parent-reported (panel A) and self-reported (panel B) emotional and behavioral (E&B) difficulties in typically-developing (TD) sisters. Analyses are controlling for birth order of child with ASD and family income. Unstandardized coefficients for the simple slopes for married and single-parent homes are presented within each plot.[136_TD$IF] All values on the yaxis were transformed by adding 3 points to prevent negative values.

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Table 4 ASD Symptom Severity by Marital Status by Parental Stress Predicting Parent- and Self-Reported Typically-Developing Sisters’ Emotional and Behavioral Difficulties. Predictor Variables

Criterion Variables Parent-Reported E&B Difficulties

Self-Reported E&B Difficulties

Model 1 TD sister age Birth order of child with ASD Family income R2

0.38 (0.38)
0.25 (0.75) [138_TD$IF]
0.17** (0.42) 0.17*

0.38 (0.41) 0.39 (0.79)
0.48 (0.45) 0.06

Model 2 Marital status ASD symptom severity Parental stress DR2

0.22 (1.79) 0.19** (0.06)
0.88y (0.45) 0.16*

0.79 (2.02) 0.13* (0.06)
0.32 (.51) 0.08

Model 3 Marital status X ASD symptom severity Parental stress X ASD symptom severity Marital status X Parental stress DR2


0.32* (0.12)
0.03 (0.02) 0.30 (1.26) 0.10y


0.36* (0.14)
0.05y[139_TD$IF] (0.03) 0.51 (1.39) 0.15*

Model 4 ASD SS X Marital status X Parental stress DR2


0.02 (0.08) 0.001


0.22* (0.09) 0.09*

Note: Unstandardized regression coefficients reported for each predictor with standard errors in parentheses; E&B = emotional and behavioral; ASD = autism spectrum disorder; SS = symptom severity; marital status coded 0 = separated, divorced or never married/living alone, 1 = married. y p < 0.10.

TD sisters’ emotional and behavioral problems. Each of these hypotheses was examined with parent- and self-reported measures of TD sisters’ emotional and behavioral difficulties. Relations at the bivariate level were mostly expected: ASD symptoms were associated with difficulties in TD sisters and parental stress, and single parents reported higher levels of stress. These data support previous findings that ASD symptoms can be stressful for both parents and TD siblings (Hastings, 2003; Hastings & Petalas, 2014; Ingersoll & Hambrick, 2011). In addition, increased stress among single parents of those with developmental disabilities is often attributed to the lack of support provided by a spouse that can help to buffer against stressors related to childcare (Upadhyay & Havalappanavar, 2007). Interestingly, parental stress was not related to TD sister functioning when examined in isolation. This was not necessarily unexpected given that parents were asked to focus on stressors related to raising their child with ASD; at the bivariate level, TD sister functioning appears independent of this type of parental distress. Our hypotheses were partially supported. After accounting for relevant demographics, main effects emerged indicating that greater siblings’ symptom severity corresponded to higher emotional and behavioral problems among TD sisters (both parent- and self-report) in each of the models tested. Moreover, marital status moderated the relations between siblings’ symptom severity and TD sisters’ emotional and behavioral difficulties (both informants). However, the direction of the interaction was somewhat unexpected. Specifically, for both parent- and self-report, TD sisters with siblings with relatively severe ASD symptomatology and with unmarried parents displayed the highest levels of emotional and behavioral problems. Yet, TD sisters with siblings with relatively less severe ASD symptomatology and with unmarried parents displayed the lowest levels of emotional and behavioral difficulties. Furthermore, counter to expectations, parental stress did not serve as a moderator when predicting TD sisters’ emotional and behavioral difficulties. ASD symptom severity was related to TD sister functioning irrespective of parental stress. Nevertheless, parental stress appears to be an important variable to consider in the context of parent marital status when examining sister self-report. The three-way interaction between parental stress, marital status, and ASD siblings’ symptom severity was only significant when predicting self-reported TD sisters’ emotional and behavioral problems. The same aforementioned interaction pattern between marital status and ASD symptom severity emerged but was only present under conditions of moderate and high levels of stress, and the pattern was most pronounced when parental stress was relatively high. These results indicate that TD sisters of siblings with less severe ASD symptoms and unmarried parents showed resilience and were the most well-adjusted. The current findings with TD sisters are consistent with previous research showing positive relations between ASD symptom severity and poorer outcomes in TD siblings (Hastings, 2003; Hastings & Petalas, 2014). Given the long-held notion that children within single-parent households are at greater risk for problems (e.g., Amato, 2001), one would expect that sisters of siblings with severe ASD within single-parent households would be at greatest risk for emotional and behavioral difficulties, which was supported by the data. However, our data further suggest that these constructs may relate differently when symptoms among children with ASD are relatively mild.

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[(Fig._2)TD$IG]

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Fig. 2. Interactions between autism spectrum disorder (ASD) symptom severity and marital status predicting self-reported emotional and behavioral (E&B) difficulties in typically-developing (TD) sisters at low (panel A), moderate (panel B), and high (panel C) levels of parental stress. Analyses are controlling for TD sister age, birth order of child with ASD, and family income. Unstandardized coefficients for the simple slopes for married and single-parent homes are presented within each plot. [137_TD$IF]All values on the y-axis were transformed by adding 3 points to prevent negative values.

Because of the increased burden and stress placed on parents of children with ASD (Davis & Carter, 2008; Fisman et al., 2000; Guralnick et al., 2008; Hastings & Brown, 2002), TD sisters may have greater responsibilities for caring for their sibling with ASD, especially when only a single parent is present. The increased responsibility experienced by TD sisters is sometimes described as parentification (when children assume tasks and responsibilities typically reserved for adults; Hooper, Doehler, Wallace, & Hannah, 2011). Whereas parentification is often associated with negative outcomes in children (Hooper et al., 2011), there is recent evidence that parentification directed toward siblings may actually be related to positive outcomes (Cridland et al., 2015; Tomeny, Barry, & Fair, in press). As such, sisters, in particular, may experience some benefits from being charged with these tasks, but only when their sibling’s ASD symptomatology is relatively mild and they are presumably more successful in their caregiving roles. Furthermore, our results indicate that this phenomenon may be most salient when parents are single and highly distressed, as they may be more reliant on TD sisters. Scenarios likely exist in which TD sisters within single-parent homes assume relatively high caregiving responsibilities, particularly when their parents are highly stressed. Despite these extra challenges, many TD sisters may feel more accomplished, develop stronger sibling relationships, and show overall resilience when their siblings with (relatively mild) ASD are responsive to their efforts. Although such roles may be protective in these ways, there will be variability in sibling reactions to increased responsibility. In other words, just as in parents, there is likely a point where this responsibility becomes too burdensome and maladaptive, particularly if siblings with ASD have severe symptoms and are less responsive to caregiving efforts. 8.1. Limitations and directions for future research Several limitations should be considered when interpreting these results. The sample was relatively small and homogenous in many ways (e.g., ethnicity, socioeconomic status), which may limit the generalizability of results. Though

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data were collected nationwide, data were not collected in a systematic way that would allow for examination of possible regional differences. Also, data were collected cross-sectionally via a technique that allows for little control of the environment in which questionnaires are completed and that could be susceptible to sampling bias. Nevertheless, the use of multiple informants should be considered a strength in counterbalancing problems with the sample. Still, future research that replicates these findings with larger, more diverse samples reached via varied sampling procedures may increase the variability of the sample and allow participation among families who are difficult to reach electronically. Studies using a longitudinal design would allow for the examination of developmental factors and whether the interrelations of the variables of interest change over time. Another limitation was that diagnostic classification of siblings with ASD was not independently verified. Future research would benefit from direct assessment of participants to confirm or disconfirm diagnoses. Although the current study utilized report from both parents and TD sisters, future research could also benefit from gathering information from additional reporters (e.g., both mothers and fathers, teachers) to obtain a more global measure of child or parent functioning. Moreover, this study focused primarily on family/contextual variables as predictors of TD sister functioning. Personal characteristics of the TD sisters themselves (e.g., temperament/personality factors, coping practices) likely attribute to substantial variance in their functioning—future research is needed to better understand the contributions of these characteristics. Additionally, given the current results, further examination of parental relationships is warranted. For instance, the quality of these relationships may explain additional variance in child outcomes above and beyond that explained by marital status. This is likely an important variable to consider in future sibling research. Whereas this study was designed to examine sisters specifically, inclusion of only sisters could be viewed as a limitation. Yet, we argue that examination of sisters’ functioning is particularly important for a variety of reasons. Some have suggested that sociocultural influences pressure women more so than men to care for family members in need (McGraw & Walker, 2007). Research indicates that TD sisters expect to assume different and more caregiving roles and responsibilities compared to their male counterparts (Burke et al., 2012; Cridland et al., 2015; Orsmond & Seltzer, 2000), and this mindset likely begins to form at an early age (Floyd et al., 2009). Nevertheless, TD sister outcomes vary greatly and many sisters show strong resilience to these challenges (Orsmond & Seltzer, 2000). Therefore, understanding early predictors of these different outcomes for TD sisters remains a high priority. Notwithstanding the importance of examining TD sisters, TD brothers deserve equal attention. Taken together, this literature suggests that predictors of functioning may differ for a similar sample of TD brothers. For example, given that many parents may have lower caregiving expectations for TD brothers, relations between ASD symptom severity and TD brother functioning may be less dependent on parent marital status. In other words, even if only one parent is present, TD brothers with single parents may have fewer expectations placed on them, relative to TD sisters, to assist with caring for their sibling with ASD. Alternatively, because TD brothers are less likely to expect being placed in a caregiving role, they may be less likely to experience benefits related to caring for their sibling with ASD when given these responsibilities. Finally, this study focused primarily on potentially negative outcomes (i.e., emotional and behavioral difficulties) among TD sisters of children with ASD. However, it is important to recognize that mean SDQ scores fell within the Normal range based on normative data (Goodman, 1997), suggesting that the majority of TD sisters in our sample were functioning well. As such, future research should focus not only on the absence of negative outcomes among siblings of children with ASD, but also on the presence of positive outcomes, such as self-esteem, pro-social behavior, and resilience. Sibling-focused programs, such as SibShops (Meyer & Vadasy, 1994) and other group-based support interventions, typically aim to improve various domains in TD siblings, such as support, emotional and behavioral functioning, and self-esteem. Though the research investigating the effectiveness of these efforts remains unclear (Tudor & Lerner, 2015), anecdotal reports suggest that TD siblings often enjoy these groups and find them to be positive experiences. Examination of functioning among families of children with ASD from a balanced perspective, assessing both risk- and protective-factors, as well as positive and negative outcomes, will provide a more complete picture of these families. These efforts will allow researchers and clinicians to further develop interventions to improve the functioning of TD siblings and their families and enhance the positive qualities already in existence. 8.2. Conclusions and clinical implications Literature examining TD siblings of children with ASD remains somewhat inconclusive with wide variability in sibling outcomes observed (Meadan et al., 2010). Based on our pattern of findings, we suggest that TD sisters may by more likely to assume caregiving roles when parents are unmarried and stressed, and TD sisters may be more successful in these roles when their sibling has relatively mild ASD symptoms, ultimately leading to more positive adjustment and functioning among TD sisters. Our findings indicate that clinicians treating families of children with relatively severe ASD and unmarried parents should be particularly cognizant of the functioning of TD sisters. Alternatively, our data also suggest that TD sisters with unmarried parents and siblings with relatively less severe ASD symptomatology may experience developmental benefits. This study provides additional support for interventions aimed at improving the quality of sibling interactions and TD sibling self-efficacy when faced with responsibilities related to sibling care.

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