Randomized controlled trial of a sibling support group: Mental health outcomes for siblings of children with autism

Abstract

Typically developing siblings of a child with autism spectrum disorder may be at increased risk of mental health difficulties. A support group is one approach to improve mental health outcomes for typically developing siblings. During support groups, typically developing siblings discuss their feelings, learn coping strategies and problem-solving skills, and develop a peer network. We conducted a randomized controlled trial comparing a support group to an attention-only social control group. Some areas of mental health improved. Autism spectrum disorder symptom severity in the sibling with autism spectrum disorder moderated effects. Findings suggest continuing to examine what areas of mental health and adjustment are improved with support groups and subgroups of typically developing siblings for whom support groups might be particularly effective.

Lay abstract

Typically developing siblings of a child with autism spectrum disorder may show mental health difficulties. A support group is one approach to help typically developing siblings. During support groups, typically developing siblings discuss their feelings, learn coping strategies and problem-solving skills, and develop a peer network. We compared a support group to participation in a similar group without a focus on the sibling with autism spectrum disorder. Some areas of mental health improved. Improvements were also impacted by autism spectrum disorder symptom severity in the sibling with autism spectrum disorder. Findings suggest continuing to examine how support groups can help typically developing siblings and for which siblings support groups might be particularly effective.

Keywords

autism spectrum disorder mental health sibling adjustment support group typically developing siblings

The presence of a child with autism spectrum disorder (ASD) in a family may affect the mental health and adjustment of all family members, including typically developing (TD) siblings. A number of studies find that TD siblings of a brother/sister with ASD are at increased risk of mental health difficulties compared with siblings in general (Griffith et al., 2014; Hastings, 2003; K. A. Meyer et al., 2011; Shivers et al., 2013) though not necessarily showing clinically significant levels of maladjustment (Hastings, 2003; Jones et al., 2019; Ross & Cuskelly, 2006). TD siblings may be especially at risk for internalizing difficulties including symptoms of depression and anxiety (Lovell & Wetherell, 2016; Macks & Reeve, 2007; Petalas et al., 2009). However, findings are equivocal (Meadan et al., 2010). Some studies find TD siblings of children with ASD show similar adjustment compared with siblings of TD children (Hastings, 2007; Kaminsky & Dewey, 2002; Tomeny et al., 2012; Walton & Ingersoll, 2015). Some studies even find positive outcomes such as more positive self-concept and greater empathy and patience compared with siblings of TD children (Macks & Reeve, 2007; Verté et al., 2003).

Factors that may relate to TD sibling mental health outcomes include sibling with ASD autism severity and problem behavior. Behavior problems in the sibling with ASD negatively impact TD sibling adjustment (Benson & Karlof, 2008; Hastings, 2003, 2007; Jones et al., 2019; Orsmond & Seltzer, 2009; Petalas et al., 2012), including self-reported depression (Lovell & Wetherell, 2016) and anxiety (Shivers et al., 2013). In some studies, more severe ASD symptomatology is also related to TD sibling maladjustment (e.g. Benson & Karlof, 2008; K. A. Meyer et al., 2011), though not in others (Shivers et al., 2013). Witnessing or experiencing aggression from their sibling with ASD is likely a scary situation for TD siblings. TD siblings may even imitate behaviors in which their siblings with ASD engage and react to parent stresses handling challenging behavior in their siblings with ASD.

The effect of having a sibling with ASD on TD sibling mental health is important to the lifelong sibling relationship and affects the entire family system. As children, TD siblings provide opportunities for social, communication, and play development. As they grow into adulthood, TD siblings take on support and caregiving roles (Dew et al., 2004; Holmes & Carr, 1991; Rossetti et al., 2018).

A support group is one approach to improving mental health in TD siblings. Support groups are generally led by an adult who engages siblings in carefully planned activities to discuss issues and emotions, build a support network, and learn about coping strategies and their sibling’s disability. A small literature suggests improvements associated with support group participation for TD siblings who have a sibling with a range of diagnoses (e.g. D’Arcy et al., 2005; Evans et al., 2001; McLinden et al., 1991; for review, see Tudor & Lerner, 2015). For example, D’Arcy et al. (2005) examined the effects of a 4-month long support group based on Sibshops (Meyer & Vadasy, 1994) for siblings of a brother/sister with physical and/or intellectual disabilities. TD siblings showed no significant improvement in self-esteem, but did report that they enjoyed the meetings and talked more with their families about having a sibling with a disability. McLinden et al. (1991) examined the effects of six weekly 1-h meetings of a support group for siblings of brothers and sisters with special needs. The group focused on peer support, and discussing feelings and coping strategies. Compared with siblings who did not participate in the support group (not randomly assigned to groups), siblings in the group showed improvements in their perception of support, but not behavior problems, self-concept, or knowledge about special needs.

Studies of support groups tend to include heterogeneous groups of TD siblings of children with developmental disabilities, a broad category reflecting children with a range of needs. Some of the concerns and challenges faced by a TD sibling of a child with cancer or a TD sibling of a child with a learning disability are different than those faced by a TD sibling of a child with ASD. For example, TD siblings of a child with ASD may witness or be the recipient of severe aggression from their sibling with ASD and struggle to communicate with their sibling with ASD who may show limited language skills, issues that are less likely to be the primary concerns of TD siblings of a child with a medical illness. Such heterogeneous groups may not meet the needs of all the TD siblings because of differences in their siblings’ diagnoses (Kryzak et al., 2015; Smith & Perry, 2005).

There are a few studies of support groups involving homogeneous groups of TD siblings who have a brother/sister with ASD (Cooke & Semmens, 2010; Kryzak et al., 2015; Smith & Perry, 2005). In addition to the topics in other support groups, these groups also focus specifically on knowledge about ASD. The groups were similar in duration and frequency with TD sibling groups meeting for 1–2 h weekly for 7–8 weeks. Overall TD siblings of a child with ASD showed some improvements. As highlighted by Tudor and Lerner’s (2015) review of interventions for TD siblings of children with developmental disabilities, a variety of measures were used and different outcomes emerged across the studies. Kryzak et al. (2015) found improvements in peer network, depressive symptomology, and anxiety with significant decreases in physiological anxiety. Improvements in knowledge about ASD approached significance. Smith and Perry (2005) found improvements in sibling self-concept and knowledge about ASD, but no change in anger and resentment toward the sibling with ASD. Cooke and Semmens (2010) found improvements in knowledge about ASD. These findings suggest continuing to explore support groups, but the pre-post designs with no control group do not provide a rigorous demonstration of the effects of a support group.

Recently, Brouzos et al. (2017) examined the effects of a psychoeducational group compared with a no treatment control group (it is not clear how siblings were assigned to groups). TD siblings of children with ASD who participated in the psychoeducational group for 90 min per week for 8 weeks showed improvements in their knowledge about ASD along with decreases in self-reported coping/adjustment difficulties and emotional/behavioral problems.

Building on our previous study (Kryzak et al., 2015) of a support group for TD siblings of children with ASD, in this study we conducted a randomized controlled trial. The support group curriculum was designed for siblings of children with ASD and compared with a similar curriculum that specifically did not include a discussion of feelings related to the sibling with ASD and family, problem-solving and coping skills, peer network, or information about ASD (attention-only control group). This provided a comparison of the support group to a group without the presumably active ingredients, a comparison not made in previous studies. We examined the effects of the support group with measures from multiple informants (both parents and TD siblings) and in relation to characteristics of the sibling with ASD. Specific research questions are:

What are the effects of the support group on TD sibling and parent report measures of mental health?

Does sibling with ASD symptomatology or externalizing behavior moderate the effects of the support group?

We hypothesized that the support group would be associated with improvements in TD sibling mental health. In addition, we hypothesized that more severe symptomatology and/or problem behavior in the sibling with ASD would moderate the effects of the support group such that TD siblings of children with ASD showing more severe symptomatology or problem behavior would benefit more from the support group.

Method

Six cohorts of participants (total of 98) who attended a program for children with ASD and their siblings at Queens College, from 2014 to 2016, participated. Children participated in the program for 2 h a week for 10 weeks. During the 2 h, siblings with ASD received individualized instruction in social, communication, and skills for the first hour while their TD siblings participated in either the support group or attention-only control group. During the second hour, all children came together for inclusive recreation activities (e.g. stretches, relay races). Undergraduate and graduate students participating in experiential learning, practicum, and independent research courses staffed the program.

To be eligible for the program, a family needed to have a child with ASD (diagnosis reported by parents from an outside source) and a TD sibling (i.e. with no known ASD diagnosis). The program did not exclude families with TD siblings who may have had other disorders (e.g. language disorder or attention-deficit hyperactivity disorder).

Information about the program was distributed via mailed fliers and emails to schools and agencies/professionals providing direct services to children with ASD as well as posted on list serves supporting families with an individual with ASD. Once a family inquired about the program, a parent completed screening questionnaires to determine eligibility. Since the program included novice undergraduate student interventionists, children with a history of severe self-injury or aggressive behavior were not included in the program. Participants for this research were recruited from those who attended the program.

Sample

The flow chart in Figure 1 shows enrollment, randomization, and allocation numbers. A total of 44 families (35 families with two siblings, 8 families with 1 sibling with ASD and 2 TD siblings, and 1 family with 1 sibling with ASD and 3 TD siblings) participated in this study, resulting in a total of 54 TD siblings and their 44 siblings with ASD participating. Mean age for TD siblings was 8.31 years (SD = 3.52) and siblings with ASD was 7.43 years (SD = 3.37). Although the TD siblings in the attention-only control group were slightly older (M = 8.62 years, SD = 3.75, range = 4–15 years) than those in the support group (M = 7.92 years, SD = 3.25, rage = 3.5–18 years), their ages were not significantly different (χ²(14) = 22.85, p = .06). The ages of the siblings with ASD also did not differ between the groups (χ²(13) = 15.87, p = .26). In the control group, 15 TD siblings were older than their siblings with ASD, 13 were younger, and 2 were of the same age. In comparison, in the support group, 12 TD siblings were older than their siblings with ASD, 9 were younger, and 3 were of the same age. Characteristics of the sample are summarized in Table 1. Information about some of the siblings prior to participation in the support group or attention-only control condition was published in (Kryzak et al., 2015).

Figure 1.

Eligibility, randomization, and allocation of participants to the support and attention-only control groups.

Table 1.

Sibling and family characteristics.

	Support group n = 24	Control group n = 30	Tests for difference between group
	n	n	Tests for difference between group
TD sibling sex			χ²(1) = 3.38, p = .06
Sisters	10	20
Brothers	14	10
Sibling with ASD
Sisters	3	5
Brothers	18	18
TD sibling race/ethnicity (n = 2 missing)			χ²(5) = 3.16, p = .68
White	4	6
Mixed race/ethnicity	3	6
Asian	13	10
Hispanic/Latina/o/x	2	6
Guyanese	1	1
CARS—Sibling with ASD (n = 1 missing)			χ²(2) = 2.09, p = .35
Minimal to no symptoms	6	6
Mild to moderate symptoms	4	10
Severe symptoms	10	9
TD internalizing range (n = 3 missing)			χ²(2) = 4.27, p = .12
Clinical	0	2
Borderline clinical	2	0
Normal	19	28
TD externalizing range (n = 3 missing)			χ²(1) = .86, p = .36
Clinical	2	1
Borderline clinical	0	0
Normal	19	29
Parent marital status (n = 5 missing)			χ²(3) = 3.21, p = .36
Married	18	25
Divorced	3	1
Domestic partners	0	1
Never married	0	1

TD: typically developing sibling; CARS: Childhood Autism Rating Scale; CBCL: Child Behavior Check List; ASD: autism spectrum disorder. CBCL Internalizing and Externalizing T scores > 69 fall in the clinical range, T scores between 65 and 69 fall in the borderline clinical range, and T scores < 65 fall in the normal range.

Design and assignment

A randomized controlled trial was used to compare the support group to an attention-only control group. Once accepted into the program, the coordinator of the program, independent of the researchers, randomly assigned families to either the support group or attention-only control group using a random number generator. Families rather than siblings were randomly assigned so that all TD siblings in a family were assigned to the same condition.

Procedure

Upon acceptance to the sibling program, families received registration packets and were randomly assigned to either the support group or attention-only control group. Registration packets contained required forms for the program (e.g. emergency contact information), TD sibling and parent report questionnaires described shortly, and consent forms requesting the use of this information for research. Packets were sent to families approximately 2–3 weeks before the onset of the program to be completed and returned prior to or on the first day of the program. This study was approved by the Queens College institutional review board and performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Families provided informed consent to participate in this research. Families received packets containing post-intervention measures on the ninth week of the program to return at the last session.

Siblings attended the program for 2 h on 10 Saturday or Sunday mornings. The program ran during each fall and spring semester. Regardless of the group to which the TD sibling was randomly assigned, all siblings with ASD received 1 h of individualized instruction while their TD sibling participated in one of the sibling groups (in separate classrooms). During the second hour all children attended an inclusive recreation time (in a large open classroom).

The support group and attention-only control group were led by a graduate student with the assistance of another graduate or advanced undergraduate student (trained and supervised by the first and last authors). Graduate students were enrolled in PhD and Master’s level graduate programs in psychology. They had backgrounds in implementing social skills group interventions for children with a variety of needs, interventions for children with ASD, and group interventions. Undergraduate students were psychology majors who had excelled during their participation in the sibling program.

Sibling support group

The support group followed a manualized treatment that drew from other sibling support group curricula such as SibShops (Meyer & Vadasy, 1994) and our own experiences and previous studies (Kryzak et al., 2015). Lessons and activities focused specifically on characteristics of ASD. Weekly topics and activities are outlined in Table 2. The group of TD siblings met together with the leaders. For some activities and discussions, the leaders split the larger group into two smaller groups to create groups with more homogeneous ages. This was done to facilitate discussions appropriate for children’s ages.

Table 2.

Outline of support group curriculum.

Week	Topic	Support group	Attention-only control group
1	Learn about the group	Share about themselves to help siblings become comfortable with one another and familiar with the other children in the group.	Share about themselves to help siblings become comfortable with one another and familiar with the other children in the group.
2	Learn about each other	Share about themselves and their families with the group.	Share about themselves and their friends with the group.
3	Share feelings	Share family situations and their feelings about their siblings with ASD.	Share feelings about friends.
4	Sibling similarities and feelings	Share similarities about their siblings with ASD and feelings, both good and bad ones. Discuss and brainstorm coping strategies.	Share similarities about friends, both good and bad ones.
5	Education	Read a book about ASD. Create a definition of ASD. Identify to whom siblings can turn for help, advice, or just to talk.	Read a book (not about autism). Participate in a craft challenge (e.g., Kiragami).
6	Education	Ask and answer questions about ASD during jeopardy style game.	Ask and answer questions about popular children’s topics during jeopardy style game.
7	Education and games	Review autism definition and identify questions for the following week’s meeting with an adult guest who has a sibling with autism.	Play name game making up poems about friends for each letter of the alphabet.
8	Guest visitor	Listen to and ask questions of an adult who also has a sibling with ASD who visits the group.	Create an art project with a guest visitor to the group (no discussion from visitor about sibling with ASD).
9	Helping siblings/friends	Discuss and identify positive characteristics of sibling with ASD and problem solve situations when their sibling with ASD may not be able to stand up for him/herself.	Play various games about friends from earlier in the program.
10	Reflection	Reflect on the group activities and discussions and make cupcakes.	Reflect on the group activities and discussions and make cupcakes.

ASD: autism spectrum disorder.

In the first week, the siblings created their group name sign to hang on their door. During the first few weeks, activities and discussions focused on learning about other group members to develop group rapport and a peer network and learn about group members’ similarities and differences. For example, siblings played the “Sit down if . . .” game in which the leader read statements such as, “Sit down if your favorite color is blue,” and, “Sit down if you like to play sports.” Following each statement, siblings sat down if the statement applied to them. Siblings played several versions of a candy game in which they drew different colored candies from a bag. Each color corresponded with something to share with the group. The game began with sharing about themselves (e.g. if the sibling drew a pink candy, the sibling named his or her favorite food) and progressed to sharing about their brother/sister (e.g. if the sibling drew a red candy, the sibling shared something about his or her brother/sister that makes him or her mad).

Discussions and activities also focused on different ways to cope with frustrations with siblings (e.g. take a deep breath, tell a parent) and who to go to for help. As a group the siblings read a book about ASD, created a definition of ASD, asked the leader and each other questions about ASD, and learned from an adult who has a sibling with ASD. On several weeks, the siblings took home weekly challenges to practice something at home or talk to their parents about something they had discussed. This helped inform parents of the activities in the support group and encouraged siblings to engage in activities with their sibling with ASD at home.

Attention-only social control group

In this group, TD siblings participated in similar activities as the siblings in the support group, but without leaders focusing discussion on ASD and feelings, or teaching coping and problem-solving skills. For example, when the support group played a jeopardy style trivia game about ASD, in the attention-only control group TD siblings played a jeopardy game about popular children’s topics such as movies, books, and games. When the TD siblings in the support group played the candy game sharing their feelings about their siblings with ASD, in the attention-only control group TD siblings played the candy game about their friends. TD siblings may have brought up having a sibling with ASD; however, this was at their discretion and not emphasized by the group leaders.

Measures of mental health and adjustment

Parents and TD siblings completed measures we mailed 2–3 weeks prior to the start of the program and families returned either by mail prior to the start of the program or on the first meeting date. On the ninth week of the 10-week program, families received the measures again to complete and return on the last meeting of the program. All measures were not fully sampled because some TD siblings were outside of the age range appropriate for the measure.

Depression

TD siblings completed the Children’s Depression Inventory—2nd Edition (CDI-2; Kovacs, 2011) by rating each of 28 items describing depressive symptoms on a 3-point ordinal scale. The measure is designed for children ages 7–17. Higher total scores indicate greater depressive symptomatology. Psychometric analyses show acceptable to high levels of internal consistency (α = .67 to .91 for all subscales including the total score; Bae, 2012). The CDI-2 also shows good construct, discriminate, and convergent validity (Bae, 2012). In the current sample, the CDI showed good internal consistency, α = .87.

Anxiety

TD siblings 6 years of age and older completed the Revised Children’s Manifest Anxiety Scale–Second Edition (RCMAS-2; Reynolds & Richmond, 2008) by rating each of 37 items either yes or no. The RCMAS-2 yields an overall score and subscale scores for defensiveness, physiological anxiety, worry, and social anxiety with higher scores indicating greater symptoms of anxiety. Psychometric analyses provide support for construct validity (Lowe, 2014). Internal consistency ranges from .77 to .87 (Lowe, 2014). In the current sample, the RCMAS appeared to have good internal consistency, α = .89.

Support

TD siblings responded yes or no to five questions about their support network such as whether the TD sibling knows any other children who have brothers/sisters with ASD and who they talk to about their sibling with ASD and their feelings. Total number of yes responses provides a support score, with higher values indicating more support. In the current sample, the support measure showed good internal consistency, α = .72.

Coping

TD siblings between 9 and 13 years completed the 62-item self-report Children’s Coping Strategies Checklist (Ayers et al., 1996). TD siblings rated the frequency of the strategies described in each statement on a 4-point scale (1 = Never, 2 = Sometimes, 3 = Often, and 4 = Most of the time). Higher total scores indicate better coping skills. Cronbach’s alpha scores ranged from .52 to .83 across scales and subscales (Camisasca et al., 2012). In the current sample, the coping measure showed good internal consistency, α = .93.

Internalizing and externalizing behaviors

Parents completed either the preschool (1.5–5 years) or school age (6–18 years) version of the Child Behavior Checklist (Achenbach and Rescorla, 2000, 2001) for each sibling (TD and sibling with ASD) separately about recent difficulties. Parents rated statements about the child’s behavior on a 3-point scale (0 = Not True, 1 = Somewhat or Sometimes True, and 2 = Often or Very True). Higher scores indicate greater levels of maladjustment.

The Child Behavior Check List (CBCL) has extensive normative data with reported high validity and reliability (Achenbach & Rescorla, 2000, 2001); Achenbach and Rescorla report high (most correlations in the .90s) test–retest correlations for the internalizing, externalizing, and total scores over a week to 2 week period. The CBCL also discriminated children who have been referred for treatment or special education services and those who have not. In the current sample, the CBCL showed good internal consistencies for both the preschool and school age versions for TD siblings (α = .99 and α = .96, respectively) and siblings with ASD (α = .97 and α = .96, respectively).

ASD severity

On the third week of the program (after two 2 hour sessions of the program), advanced graduate students in PhD and MA programs at Queens College (overseen by the first author) and the last author evaluated each sibling with ASD using the Childhood Autism Rating Scale^TM, 2^nd edition (Schopler & Van Bourgondien, 2010). Staff completed the CARS during observations of children’s individualized instruction sessions without the TD siblings present. The CARS is a behavior rating scale for children 2 + years used to aid in ASD diagnosis. Ratings are summed to produce a total score with higher values indicating more severe autism symptomatology. Schopler et al. (2010) reported good reliability and validity and good internal consistency (α= .73 to .94). Interrater reliability was also high for the Total score (r = .95). Lord et al. (1999) reported that using a Total raw score cutoff of 30 correctly identified 87% of their sample as having ASD or not and total scores correlated with Autism Diagnostic Observation Schedule total scores (r = .77). In the current sample, the CARS showed very good internal consistency,α = .95.

Data analysis

Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 24.0 (Armonk, NY). Table 3 provides information about missing data for each measure. Little’s Missing Completely at Random (MCAR) test demonstrated that missing data points were indeed a random subset of the data, χ²(246) = 225.70, p = .82. Consistent with recommendations in the literature (e.g. Schlomer et al., 2010), we then used multiple imputation procedures for support and control group data separately prior to further analysis.

Table 3.

Missing measures for control and support groups.

Measures	Control		Support
Measures	n	Missing	n	Missing
TD sibling
Depression pre	17	2	13	4
Depression post	11	8	5	12
Anxiety pre	16	5	15	2
Anxiety post	11	10	6	11
Support pre	20	10	18	6
Support post	16	14	8	16
Coping pre	21	9	11	13
Coping post	16	14	7	17
Internalizing pre	25	5	17	7
Internalizing post	20	10	10	14
Externalizing pre	25	5	17	7
Externalizing post	20	10	10	14
Sibling with ASD
ASD symptomatology	22	2	19	3
ASD Internalizing pre	17	7	14	8
ASD Internalizing post	16	8	9	13
ASD Externalizing pre	17	7	14	8
ASD Externalizing post	16	8	9	13

TD: typically developing siblings; ASD: autism spectrum disorder. Some measures had limited age ranges and were not applicable for some children who fell outside that age range. n and missing numbers refer to the number of children for whom the measure was applicable.

For some measures, some children were not within the age range for which the measure was designed, resulting in different sample sizes across some measures. Each analysis involved only those participants with values for all variables in the analysis.

Group and time analysis

Mixed analysis of variance (ANOVA) analyses with one between-subjects factor (group: support vs control) and one within-subjects factor (pre- vs post-intervention) were computed separately for each of the following variables: (1) depression; (2) anxiety; (3) support; (4) coping skills (5) TD sibling internalizing behaviors; and (7) TD sibling externalizing behaviors. Significant main effects and interactions were followed up by post hoc examination of pairwise comparisons. The homogeneity of variance assumption was assessed by Levene’s test. Effect sizes were calculated using the ANOVA function in IBM SPSS Statistics yielding partial eta-squared for each main effect and interaction.

Moderation analysis

We conducted moderator analyses of sibling ASD severity and sibling ASD externalizing behavior separately to test the hypothesis that TD sibling adjustment is a function of multiple risk factors (ASD sibling symptomatology and externalizing behavior) using PROCESS v. 3.0 (Hayes, 2018), recommended by Field (2018). We normalized variables before creating the interaction term to avoid collinearity between the interaction and the individual predictors (Field, 2013). The first set of moderation analyses focused on ASD sibling symptom severity as indexed by the CARS score. The following predictors were entered in the same block: (1) z-scored group variable (control = 0; support = 1); (2) z-scored pre-intervention CARS scores of the sibling with ASD; and (3) their interaction. Pre-intervention scores of the respective post-intervention scores were entered as covariates to control the effects of pre-intervention scores. This regression was computed separately for each of four post-intervention z-scored variables: (1) depression; (2) anxiety; and (3) coping.

The second set of moderation analyses focused on ASD externalizing behavior as indexed by the CBCL-E score. The following predictors were entered in the same block: (1) z-scored group variable (control = 0; support = 1); (2) z-scored pre-intervention CBCL-E scores of the sibling with ASD; and (3) their interaction. Pre-intervention scores of the respective post-intervention scores were entered as covariates to control the effects of pre-intervention scores. This regression was computed for post-intervention z-scored depression.

Results

Treatment fidelity and attendance

The assistant leader in each group rated treatment fidelity for 73% of weekly sessions of the support group and 68% of weekly sessions of the attention-only control group. The assistant leader completed a checklist of the steps of the curriculum noting whether each step was completed, not completed, or not applicable (e.g. if the group ran out of time). Fidelity ranged from 71% to 100% for both groups with a mean of 95% for the support group and a mean of 96% for the attention-only control group (fidelity median and mode were 100% for both groups). For the support group, 88% of the TD siblings attended seven or more of the sessions; for the control group, 96% of TD siblings attend seven or more of the sessions.

Group analysis

Table 4 illustrates descriptive statistics for pre- and post-intervention scores as a function of group membership and ANOVA main effect, interaction results, and effect sizes. There were no significant differences in scores between groups on any of the measures at pre-intervention assessments, except for TD sibling’s coping skills. There were no significant differences between groups on any of the post-intervention measures.

Table 4.

Descriptive statistics pre- and post-intervention as a function of group and mixed ANOVA.

	Pre-intervention		Post-intervention		Group main effect	Time main effect	Group × time interaction
	Support	Control	Support	Control
	M (SD) [n]	M (SD) [n]	M (SD) [n]	M (SD) [n]
Depression	6.83 (5.69) [16]	9.52 (6.40) [20]	4.42 (1.90) [16]	6.82 (4.64) [20]	F(1, 34) = 3.17p = .08.	F (1, 34) = 7.97 p = .008, $η_{p}^{2}$ = .19	F(1, 34) = .025p = .88.
Anxiety	11.27 (9.46) [15]	12.13 (8.07) [20]	15.19 (5.26) [15]	16.70 (8.46) [20]	F(1, 33) = . 24p = .63	F (1, 33) = 10.96 p = .002, $η_{p}^{2}$ = .25	F(1, 33) = .062p = .80
Support	1.82 (1.67) [22]	1.58 (1.27) [29]	1.95 (.84) [22]	2.19 (1.26) [29]	F(1, 49) = .00p = .99	F(1, 49) = 2.26p = .14	F(1, 49) = .92,p = .34
Coping	124.80 (32.79) [22]	146.25 (29.55) [29]	163.99 (28.79) [22]	150.51 (34.87) [29]	F(1, 49) = .28p = .60	F (1, 49) = 20.97 p < .001, $η_{p}^{2}$ = .30	F (1,49) = 13.5 p = .001, $η_{p}^{2}$ = .22
TD Internalizing	6.69 (4.61) [20]	6.47 (6.58) [29]	7.16 (7.62) [20]	5.38 (7.04) [29]	F(1, 47) = .32p = .57	F(1, 47) = .17p = .69	F(1, 47) = 1.06p = .31
TD Externalizing	8.76 (7.70) [20]	6.35 (6.52) [29]	4.25 (6.47) [20]	5.58 (6.97) [29]	F(1, 49) = .50p = .48	F (1, 47) = .7.99 p = .007, $η_{p}^{2}$ = .15	F (1, 47) = 4.02 p = .051, $η_{p}^{2}$ = .08

ANOVA: analysis of variance; TD: typically developing siblings; SD: standard deviation. The Levene’s Test for Homogeneity of Variance assumption was met for all variables. Eta squared ⩾ .01 is small effect, ⩾ .09 is moderate effect, and ⩾ .25 is large effect.

Across all TD siblings (in both the support and attention-only control groups), self-reported depressive symptoms decreased and coping skills increased. However, self-reported anxiety symptoms increased. In addition, parents reported lower externalizing behavior.

The group × time interaction was significant (to marginally significant) with moderate effect sizes for two measures: coping skills and TD externalizing behavior (Figures 2 and 3). Pairwise comparisons indicated that (1) the support group reported higher coping skills at post- than pre-intervention (p = .01), whereas the control group did not differ as a function of time (p = .50) and at pre-intervention, the support group endorsed significantly lower coping skills than the control group (p = . 02), whereas at post-intervention, there were no group differences (p = .15); and (2) parents reported lower TD sibling externalizing behavior problems in the support group post- than pre-intervention (p = .003), whereas parents of TD siblings in the control group did not report any difference as a function of time (p = .52).

Figure 2.

Significant group × time effects on coping skills.

Figure 3.

Significant group × time effects on TD sibling’s externalizing behaviors.

Moderation analysis —ASD symptom severity

Table 5 shows correlations between each measure.

Table 5.

Correlations between pre- and post-TD sibling measures and symptom severity and externalizing behavior of the sibling with ASD.

Measure	ASD externalizing	Pre-TD depression	Post-TD depression	Pre-TD anxiety	Post-TD anxiety	Pre-TD coping	Post-TD coping
ASD symptom severity	.028	−.087	.28	.36	.17	−.22	−.03
ASD externalizing		.58**	.29	.31	.28	−.12	−.02
Pre-TD depression			.34*	.15	1.6	−.22	−.02
Post-TD depression				.09	.37*	−.07	−.03
Pre-TD anxiety					.58**	.03	.22
Post-TD anxiety						−.11	.26
Pre-TD coping							.45**
Post-TD coping

TD: typically developing; ASD: autism spectrum disorder.

p < .05. **p < .001.

Depression

The ANOVA model was significant, F(4, 23) = 10.59, p < .001, with group, sibling ASD severity pre-intervention, and their interaction sharing 43.36% of the variance in post-intervention depression scores. With respect to the covariate pre-intervention depression scores (p = .34), and individual predictors: group alone (p = .78) and ASD severity pre-intervention (p = .13) did not share significant variance with post-intervention depression scores. Moreover, sibling ASD severity pre-intervention significantly moderated the relationship between group and post-intervention depression scores, β = 1.40, t = 3.28, p = .003. Figure 4 illustrates that although post-intervention depression scores for TD siblings in the support group were not affected by sibling ASD severity, TD siblings in the control group whose sibling experienced more severe symptoms of ASD endorsed higher post-intervention depression scores than those whose sibling exhibited less severe ASD symptoms, β = 1.04, 95% CI [.27, 1.81], t = 2.81, p = .01.

Figure 4.

Sibling with ASD symptom severity (CARS) moderated the relationship between group (Control, Support) and depression (z-scored depression scores) at post-intervention.

Anxiety

The overall ANOVA model was significant, F(4, 22) = 9.34, p < .001, with group, sibling ASD severity pre-intervention, and their interaction sharing 42.4% of the variance in post-intervention anxiety scores. With respect to the covariate pre-intervention anxiety scores (p = .06), and individual predictors: group alone (p = .98) and ASD severity pre-intervention (p = .14) did not share significant variance with post-intervention anxiety scores. Moreover, sibling ASD severity pre-intervention significantly moderated the relationship between group and post-intervention anxiety scores, β = .74, t = 2.21, p = .04. Figure 5 illustrates that although post-intervention anxiety scores for TD siblings in the support group were not affected by sibling ASD severity, TD siblings in the control group whose sibling experienced more severe symptoms of ASD endorsed higher post-intervention anxiety scores than those whose sibling exhibited less severe ASD symptoms, β = .62, 95% CI [.12, 1.11], t = 2.57, p = .02.

Figure 5.

Sibling with ASD symptom severity (CARS) moderated the relationship between group (Control, Support) and anxiety (z-scored anxiety scores) at post-intervention.

Coping

The overall ANOVA model was significant, F(4, 35) = 2.77, p = .04, with group, sibling ASD severity pre-intervention, and their interaction sharing 19.75% of the variance in post-intervention coping scores. The covariate variable pre-intervention coping skills significantly predicted post-intervention coping scores, β = .41, t = 3.24, p = .003. Group, ASD severity pre-intervention, and their interaction did not predict coping (all p > .64).

Moderation analysis —ASD externalizing

Depression

The overall ANOVA model was not significant, p = .06, with group, pre-intervention ASD sibling externalizing behavior, and their interaction sharing 30.4% of the variance in post-intervention depression scores. The covariate variable pre-intervention depression scores significantly predicted post-intervention depression scores, β = .53, t = 2.31, p = .04. Group, pre-intervention ASD sibling externalizing behavior, and their interaction did not predict depression scores (all p > .25).

Anxiety

The overall ANOVA model was not significant, p = .06, with group, pre-intervention ASD sibling externalizing behavior, and their interaction sharing 35.2% of the variance in post-intervention anxiety scores. The covariate variable pre-intervention anxiety scores significantly predicted post-intervention anxiety scores, β = .91, t = 3.14, p = .006. Group, pre-intervention ASD sibling externalizing behavior, and their interaction did not predict anxiety scores (all p > .19).

Coping

The overall ANOVA model was not significant, p = .17, with group, pre-intervention ASD sibling externalizing behavior, and their interaction sharing 18.1% of the variance in post-intervention coping scores. The covariate variable pre-intervention coping scores significantly predicted post-intervention coping scores, β = .45, t = 2.38, p = .03. Group, pre-intervention ASD sibling externalizing behavior, and their interaction did not predict coping (all p > .57).

Discussion

To the authors’ knowledge, this is the first randomized controlled trial comparing a support group to an attention-only control group for TD siblings with a brother/sister with ASD. TD siblings who participated in the support group showed significant improvements in externalizing behavior and coping skills compared with those in the attention-only control group. When the siblings with ASD showed more severe ASD symptomatology, the support group seemed to provide a buffer against TD sibling symptoms of both anxiety and depression. Our positive outcomes on select measures are consistent with some studies of support groups (e.g. Brouzos et al., 2017; Cooke & Semmens, 2010; Kryzak et al., 2015; Smith & Perry, 2005).

On several measures, siblings in both groups showed improvements (not necessarily significant). But siblings in the support group improved more than those in the control group in coping skills and parent reported externalizing behavior suggesting there is something about the active ingredients in the support group that improves mental health in TD siblings. The magnitude of the effect may be greater in comparison with a no treatment control group rather than an attention-only condition, supporting the value of support groups for improving TD sibling mental health.

Not all measures were returned from families resulting in some measures with a high percentage of missing data (e.g. coping). This may have created a self-selected sample. Fortunately, data were missing at completely random. Especially for measures with a higher percentage of missing data (e.g. coping), results must be viewed with caution. Future research must address this limitation ensuring completion of measures to have more confidence in all analyses and replicate these findings.

Both the descriptive (see Meadan et al., 2010, for a review) and intervention (see Tudor & Lerner, 2015, for a review) literatures include a variety of measures of different aspects of TD sibling mental health from different informants with inconsistent findings on those measures. We did not find any effects related to parent reported internalizing behavior, but did find the support group may have provided a buffer against increased TD sibling self-reported depression and anxiety when siblings with ASD show more severe symptomatology. Which measures and areas of mental health to examine from which informants remain questions for continued research.

The use of multiple informants to complete the measures is positive, but all measures in this study were report measures with no direct observation and completed by parents and TD siblings not blind to treatment group. For parents, the fact that both the TD sibling and sibling with ASD were attending a program that also provided individualized instruction to the sibling with ASD and inclusive recreation opportunities for the siblings may have positively impacted their reports about the effects of the program, regardless of whether the TD siblings participated in the support group or attention-only control condition. In addition, the individualized instruction and opportunities for siblings to play together during recreation activities could have influenced sibling interactions. Individualized instruction and inclusive recreation opportunities clearly were not enough to improve TD sibling adjustment as these components of the program would likely have influenced siblings in both groups similarly.

We also found no changes on several measures, such as support network, that are part of the focus of the support group curriculum. Inconsistent and lack of change on some measures may relate to the duration of the program which is very short in comparison with the lifetime siblings have to impact each other’s mental health. Increasing the duration of each weekly meeting (from 1 to 2 h) and/or the total number of weekly meetings (from 10 weeks to 15 or 20) could improve immediate and longitudinal outcomes, though this warrants future investigation.

In this study, we examined the effects of a support group on mental health in TD siblings who have a sibling with ASD, a question that presumes TD siblings, just because they have a sibling with ASD, need some sort of intervention. Our sample did not score in the clinically significant range. This is consistent with a number of studies describing mental health in TD siblings (Hastings, 2003; Jones et al., 2019; Ross & Cuskelly, 2006). Thus, intervention may not be warranted for every TD sibling. There are likely TD siblings who do not need any sort of intervention, those for whom a support group is just the right intervention, and those who may need something different than a support group. But parents brought their children to the program presumably because of parents’ perceptions of some need for their TD children. Perhaps parents’ concerns suggest still different approaches to intervention. Intervention that involved parents and both the TD siblings and siblings with ASD may address parent concerns as well as sibling needs; for example, teaching parents strategies to facilitate interactions between their children and in doing so improve sibling and parent–child interactions (Sheikh et al., 2019).

We also examined ASD symptomatology and externalizing behavior as moderators. For those TD siblings who have a brother/sister showing more severe ASD symptomatology, we found that support groups may be a buffer against increased self-reported depression and anxiety in TD siblings. This is consistent with some literature showing a relationship between ASD symptomatology (Benson & Karlof, 2008; K. A. Meyer et al., 2011) and ASD problem behavior (Benson & Karlof, 2008; Hastings, 2003, 2007; Jones et al., 2019; Lovell & Wetherell, 2016; Petalas et al., 2012; Shivers et al., 2013) and mental health. Interestingly, we did not find that problem behavior (if indexed by TD externalizing behavior) moderated the effects of intervention on TD sibling mental health. The support group may act as a buffer or alternatively, mental health of TD siblings in the control group may have gotten worse over the course of the 10-week program. There are many characteristics of TD siblings, siblings with ASD, and their families that may impact mental health and response to interventions such as support groups, and worsening of mental health over time. Despite random assignment, the groups could have differed on unmeasured characteristics that negatively impact mental health. For example, the control group had a higher percentage of TD sisters than the support group (though not significantly different). Although some studies do suggest that TD sisters show greater mental health difficulties than brothers (Orsmond & Seltzer, 2009; Tomeny et al., 2016), there are also a number of studies that suggest TD brothers are more at risk than sisters (e.g. Hastings, 2003; Kaminsky & Dewey, 2002; Macks & Reeve, 2007; Shivers et al., 2013; Verté et al., 2003; Walton, 2016) and even studies reporting no impact of gender on TD sibling adjustment (e.g. (Kaminsky & Dewey, 2002; Pilowsky et al., 2004; Verté et al., 2003). In fact, Tomeny et al. found that more severe ASD symptomatology was associated with TD sister maladjustment. Orsmond and Seltzer suggested that the gender differences in depressive symptoms may reflect factors that account for gender differences in the general population, but could also reflect some unique impact on TD sisters of having a sibling with ASD. Greater negative effects on sisters may relate to more caregiving responsibilities and other tasks than brothers (Diener et al., 2015). Additional responsibilities have been associated with more emotional distress (Barak-Levy et al., 2010), though some have questioned this explanation for higher rates of difficulties in TD sisters (Hastings, 2003).

Although this sample was large relative to other support group studies, the present study is underpowered to examine subgroups of TD siblings for whom support groups or other interventions may be particularly important. TD siblings who show clinically significant levels of mental health difficulties may actually benefit more from individual therapy. Not only do TD sisters and brothers show some differences in mental health, but those differences may interact with the gender of the sibling with ASD and the resulting gender makeup of the sibling dyad. For example, in a study of adolescents and adults with siblings with ASD, Orsmond et al. (2009) found TD adult sisters with a sister with ASD reported the most positive sibling relationships, while TD brothers of a sister with ASD reported the least positive relationship. To further complicate matters, birth order may impact TD sibling mental health. Studies show mixed findings with some suggesting TD siblings who are older than their sibling with ASD may show poorer mental health and adjustment outcomes than younger TD siblings (e.g. Rodrigue et al., 1993) and others the opposite (e.g. Tomeny et al., 2014), with relationships also moderated by behavior problems and other sibling characteristics. There may still be other characteristics to consider such as each sibling’s developmental level, TD sibling broad autism phenotype (e.g. Petalas et al., 2012; Walton, 2016), and family characteristics such as family income, parent stress, and mental health (e.g. Tomeny et al., 2016). Future research with a large enough sample and collection of information relevant to various sibling and family characteristics may help identify other moderators or factors to consider in deciding a TD sibling should attend a support group, or another intervention.

Future research should also examine the effects of other interventions with TD siblings on mental health. In addition, other interventions may be better suited to TD siblings showing certain characteristics. Support groups seem to address some of the needs of those TD siblings who have a sibling showing more severe symptomatology. But, in sibling training, TD siblings learn specific strategies to facilitate interactions with their sibling with ASD (e.g. Celiberti & Harris, 1993; Schreibman et al., 1983; Shivers & Plavnick, 2015). Continued investigation of the effects of each approach to intervention on TD sibling mental health, direct comparisons of the relative effects of each approach and combinations of approaches, and moderators of the effects of each approach may shed light on which intervention for whom provides the most benefit to mental health.

Future research may also investigate characteristics of the support group. In addition to examining the duration of the program, creating even more homogeneous groups than just siblings who have a brother/sister with ASD may be important. For example, TD siblings at a more similar age level may benefit more from discussions that are at an age-appropriate level (Cooke & Semmens, 2010; Smith & Perry, 2005). We did divide the groups when there was a wide age range in the TD siblings. This was done to allow for discussions appropriate to the ages of the smaller groups. We did find the older siblings to be helpful during discussions with the younger siblings. In this case, the diversity of ages did not seem to be an issue. However, it is important that the discussions meet the needs of the TD siblings; siblings nearing adolescence may begin to have very different questions about ASD and its impact on their future lives than those of younger elementary age children who are just beginning to understand ASD. The group may benefit from additional topics or presentation of topics in different ways. Additional discussion of advocacy, especially for an older group of TD siblings, may be particularly important.

Conclusion

This study is the first randomized controlled trial demonstrating positive effects of a support group for TD siblings who have a brother/sister with ASD compared with an attention-only social group. Siblings discussed their feelings, learned about autism, and discussed and practiced coping skills and problem-solving, while also developing a network of peers in a similar family situation. Future investigation with a larger group of TD siblings will allow for continued examination of different interventions and for whom to best address the needs of families of children with ASD.

Footnotes

Acknowledgements

We thank the families who participated. We also thank the sibling program and personnel at Queens College that enabled us to conduct this research. We thank the students in Service Corps at City University of New York who participated from 2014 to 2017.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The first and last authors received grants that partially supported this work from the Organization for Autism Research and City University of New York (PSC-CUNY, jointly funded by The Professional Staff Congress and The City University of New York (grant number 69089-00 47), Undergraduate Research and Mentoring Education, Service Corps, and Workforce Development Initiative).

ORCID iDs

Emily A Jones

Nicole Neil

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