Given the high prevalence of ER difficulties in autistic individuals and their association with mental health challenges, many treatments have been developed to support ER in autistic individuals (31–33). Examples include those that specifically target ER as well as those that support ER skills as part of broader mental health and social skills interventions (22). Interventions designed to support ER skills often aim to increase emotion awareness, distress tolerance, and ER strategy use. Some interventions take a mindfulness-based approach to supporting ER (34, 35), whereas broader mental health and social skills treatments typically include sessions devoted to teaching emotion identification and management strategies alongside other intervention elements (22). In addition to treatments that teach ER skills to support internalizing symptoms, a handful of other studies have targeted the acquisition of ER skills to prevent or reduce child behaviors like hitting others and refusing parental instructions [e.g., (36, 37)].

A growing body of research supports the efficacy of interventions supporting ER in autistic individuals, yet this research has almost exclusively occurred in older autistic youth and adults (34, 38). Moreover, research aimed at supporting ER in younger, school-age children (i.e., ages 5 to 7 years) often uses traditional skills-based programs (e.g., affective education in conjunction with teaching stress management strategies) that have been developed for older youth and adapted for younger populations (39). These studies have had promising results, with participating children showing improvements in ER skills (39). As difficulties with ER emerge early in autistic children (40, 41), more proactive and developmentally appropriate approaches to supporting ER skills are needed during critical periods in which ER is developing.

One means to proactively support the development of effective ER skills in preschool-age autistic children is through parent-mediated interventions. Parent-mediated interventions are a treatment model in which a therapist systematically teaches or coaches a caregiver to implement therapeutic strategies with their child within meaningful home and community routines (42). A growing evidence base suggests parent-mediated approaches are efficacious in reducing challenging behaviors (43) and in improving social communication in young autistic children (44). Parent-mediated interventions may also support family outcomes, including parent-child interactions and caregiver empowerment (45).

Parent-mediated intervention may be particularly well-suited to support ER skills in young children with ASD given the instrumental role that caregivers play in the development of ER for both autistic and non-autistic children (46, 47). For example, caregivers support ER development through reciprocal and transactional interactions, modeling of ER strategies, and scaffolding the use of ER strategies (48). Research has demonstrated that caregivers use a variety of strategies to support their autistic children in regulating their emotions, many of which resemble the strategies used by caregivers of non-autistic children but that are also responsive to their child's developmental needs (46). Although caregivers support ER development in both autistic and non-autistic children, little is known about the extent to which caregivers have been leveraged to bolster ER skill development through participation in parent-mediated interventions.

When considering the extent to which parent-mediated interventions support the development of ER skills, it is also important to include parent-mediated interventions focused on externalized, challenging behavior, as these behaviors may ultimately represent internal ER processes. For example, in autistic individuals, the experience of heightened anxiety (i.e., an internal emotional state) is associated with increased reporting of aggressive behaviors [e.g., (9, 49)]. It is also possible that anxiety (i.e., and internal state rooted in ER processes) may contribute to observable challenging behaviors over time [e.g., a child who engages in aggressive behaviors that result in escape or avoidance of anxiety-provoking contexts (50)]. The co-occurrence between ER processes and external behaviors suggests the need to consider that challenging behaviors may at times represent external cues of dysregulated emotional states or behavioral attempts at regulating emotional states (51).

The inclusion of parent-mediated interventions focused on externalized, challenging behaviors is also important given the historical emphasis of autism early intervention on the reduction of challenging behaviors or the replacement of challenging behaviors with other skills (43). Although a large body of research has examined the impact of early ASD treatment on challenging behavior, it is unclear the extent to which the ER processes underlying these behaviors are also measured as an outcome alongside challenging behavior [e.g., (52)]. The current study aims to address this gap by providing a systematic review of ER and/or challenging behavior as an outcome within parent-mediated interventions. A more inclusive criteria was chosen to capture the overlap between the ER difficulties and challenging behavior, as well as the prevalence of autism intervention literature targeting challenging behavior. Measuring challenging behaviors was made given the overlap between challenging behaviors and ER difficulties [e.g., (21, 50)]. Study aims were to: 1) evaluate the frequency with which ER is assessed in the context of parent-mediated interventions within early childhood, 2) determine the extent to which ER is measured concurrently with or distinctly from challenging behavior; and 3) examine whether the reviewed parent-mediated interventions aim to directly support ER skills.

The present search resulted in 20 peer-reviewed parent-mediated intervention studies for ER and/or challenging behavior (see Table 1). Fifteen studies took place in the United States (U.S.); the remaining five studies took place in Canada (54), China (55), Iran (56), Italy (57), and the Netherlands (58). Of the full sample, 10 studies took place primarily in participants' homes, and 10 took place within clinical centers or university settings. One study took place in a clinical setting that provided early intensive behavioral intervention services in addition to participant homes (57). Six studies were conducted using telehealth; three of these studies took place primarily in participants' homes (59–61), while three other studies were conducted with parent-child dyads attending telehealth sessions at a clinical site near their homes (62–64).

Empirically validated interventions were represented within the pool of reviewed studies, in addition to more novel, pilot intervention programs [e.g., (55, 69)]. The empirically validated interventions included those targeting challenging behaviors such as aggression and property destruction [e.g., Parent-Child Interaction Therapy (PCIT); Functional Communication Training (FCT)], as well as those intended to target social communication and adaptive behaviors. Variability was observed with respect to intervention duration and sample size as well. Although over half of the studies included intervention session lengths of 60- to 120-min, treatment sessions for some studies were as short as 15-min in duration (64). When considering studies that explicitly reported the number of treatment sessions, studies ranged from three to greater than 25 sessions. With respect to study methodology and sample size, 11 studies employed group designs to examine differences in participant behavior from pre- to post-treatment (range: 11–107 participants), and nine studies relied upon visual analysis using single case research designs (range: 2–5 participants).

Two studies (62, 65) used a manualized parent training intervention for challenging behavior with similar structure, intervention duration, and content within the targeted age group. A total of 180 participants participated in the Bearss et al. (65) multi-site trial, with 89 children randomly assigned to the parent training condition. In Bearss et al.'s (62) study, an additional 14 participants completed this manualized intervention with an emphasis instead on intervention feasibility when delivered via telehealth.

Eighteen of 20 studies included stated treatment targets related to challenging behaviors like self-injury, property destruction, and aggression. A total of six studies used FCT (59–61, 63, 64, 68). Of note, one study (63) included a sample that partially overlapped with two other studies (60, 64). A seventh study explicitly integrated FCT within a broader behavior analytic package for behaviors like whining, yelling, aggression, and throwing items (71). Five studies employing behavior analytic methodologies to decrease the rate or frequency of child challenging behaviors also targeted language or social communication (57, 60, 61, 70, 71).

Only two studies assessed ER in young autistic children as part of intervention (46, 69). Gulsrud et al. (46) examined ER as a secondary construct within an existing intervention dataset targeting joint attention within 34 parent-child dyads. Child ER was assessed across the intervention through behavioral coding of child negative affect as well as categorized child self-regulation strategies. In contrast, Rispoli et al. (69) developed the Regulation of Emotional Lability in Autism Spectrum Disorder through Caregiver Supports (RELACS) parent-mediated intervention, which primarily promoted ER skills in autistic preschool-age children. Reductions in child emotion dysregulation in four of five participants using a caregiver report measure at completion of the intervention were reported (69).

Goals of this systematic review were to examine the extent to which ER or challenging behavior is measured within the context of parent-mediated interventions for young autistic children, the extent to which ER is measured alongside or distinct from challenging behavior, and the extent to which ER is specifically targeted within these interventions. Overlap between ER and externalized challenging behaviors [e.g., (9, 51)] guided the decision for inclusion criteria in this review to be intentionally broad to capture studies that assessed either or both constructs. Specifically, this review included any empirical study that evaluated a parent-mediated intervention for autistic children under the age of 6 years and measured either ER or challenging behavior as an outcome using a validated scale or through behavioral observation.

A total of 20 studies met these criteria. Almost every study that met the inclusion criteria targeted challenging behavior using manualized curricula focused on behavior management principles, targeted behavior analytic interventions, or broader behavior analytic treatment packages. Studies targeting challenging behaviors, such as aggression toward others, self-injury, property destruction, and disruptive vocalizations like screaming, measured challenging behavior as a primary outcome through use of caregiver rating scales and behavioral data collection. Only one study included an intervention specifically targeting ER skill development (69). Finally, one additional study measured changes in a child's ER over the course of their participation within a parent-mediated intervention aimed at supporting joint attention skills (46). Overall, the included interventions were conducted both in-person and via telehealth, in-home and clinic-based, and ranged from three to greater than 25 sessions. In addition to the inclusion of large-scale trials that examined manualized parent-mediated interventions for challenging behavior [e.g., (65)], a strength of this review is that it captured nine single case study designs that centered on direct observation of behavior change. Many of these studies used parent-mediated intervention rooted in behavioral principles to support the use of functional communication and behavioral flexibility [e.g., (64, 67)].

To date, systematic reviews and meta-analyses of parent-mediated interventions have examined those that support social communication development as well as interventions that focus on reduction of challenging behaviors (43, 44). The extent to which parent-mediated interventions could also be used to support the development of ER skills remained largely unexamined. This limitation was important to address as high rates of ER difficulties in autistic individuals begin as early as toddlerhood (12, 41) and predict the development of interfering mental health challenges including anxiety and depression in childhood, adolescence, and adulthood (17, 23). Although a number of treatments have been designed to facilitate ER skill development, many of these are designed to support individuals in middle childhood through adulthood—well after the emergence of ER difficulties (22). The essential role of caregivers in ER development for both autistic and non-autistic children (48) as well as the potential for proactively mitigating the impact of ER difficulties over time suggests that parent-mediated interventions in early childhood may represent a natural opportunity to support ER and to examine ER as an intervention outcome.

It was not unexpected that nearly all reviewed interventions emphasized challenging behavior—particularly in the context of operant learning paradigms—when considering the historic emphasis of the field on interventions using behavior analytic principles, the presence of autism insurance mandates that have increased access to behavior analytic treatment and the relatively high co-occurrence of behaviors such as self-injury and aggression in autistic children (73–76). Of the studies targeting challenging behavior, none measured ER as a secondary outcome. This finding indicates that literature on treatments of challenging behavior in young autistic children is not measuring or supporting ER as a core process in parallel to externalizing behaviors that may contribute to these behaviors. The lack of ER measurement within the existing literature was surprising given research suggesting that some challenging behaviors may be rooted in internal ER processes [e.g., (49)].

Of the reviewed studies, only one examined a parent-mediated intervention that explicitly supported ER skills in young autistic children (69). This intervention supported caregivers in modeling ER strategies, using relevant visual supports, and managing other challenging behaviors. Within the multiple-probe single case design, four out of five children demonstrated parent-reported reductions in emotion dysregulation from pre- to post-treatment (69). Although ER was not a core target of the joint attention intervention in Gulsrud et al. (46), this study found that children decreased their expression of negative emotion over the course of treatment, while mothers increased their use of emotional scaffolding (46). Their results may suggest that parent-mediated interventions targeting social communication are able to support ER skill development through supporting caregivers' use of affect to increase social engagement and maintain regulation (77). In doing so, these interventions may support co-regulation, even when not an explicit intervention target.

The limited measurement of ER within the reviewed studies may, in part, be due to difficulty measuring internal ER processes as distinct from more observable behaviors such as aggression or self-injury. Measurement may also be hindered by few ER rating scales that have been validated in autistic toddlers or toddler with other developmental delays (17). Behavioral coding schemes developed to assess observable ER processes in young children used in conjunction with rating scales may strengthen the validity of ER measurement. In future work, behavioral coding schemes may be used to assess ER within this age group (17) and may complement observational coding that is already utilized within parent-mediated intervention [e.g., (46)]. Work is also actively being done to extend indirect ER measures with strong psychometric properties [e.g., (78)] to toddler- and preschool-age autistic populations, creating other avenues for illuminating ER difficulties in young autistic children.

Limitations of this review include the narrow age range considered as studies were included only if they had a sample of children with a mean age of 6 years or younger. This age range was chosen given the early emergence of ER challenges in autistic children and the intention of the review to examine interventions that may support ER skill development prior to the onset of more consequential ER or mental health difficulties. In doing so, this age range excluded parent-mediated interventions targeting challenging behavior in slightly older youth [e.g., (79)]. Moreover, we did not include interventions targeting ER development by teaching skills directly to young autistic children. Studies to date have adapted individual, skill-based programs for young children ages 5–7 years with promising findings (39). The selection of parent-mediated intervention was made in response to evidence demonstrating the role of caregivers in supporting ER development through co-regulation (47, 48), making parent-mediated intervention an appropriate context for supporting ER development. Finally, it is possible that the search string used [e.g., “autism” as opposed to “autis^*”] may have limited the sensitivity of the search. However, the current search strategy was used to align this review with those previously conducted on similar topics (12, 17).

Future directions include improved measurement of ER within the context of parent-mediated interventions. It will be critical to measure ER alongside challenging behavior to help tease apart whether changes in ER skills co-occur with changes in behavior or serve as the foundation by which children replace challenging behaviors with more adaptive skills. Although caregiver rating scales of ER in young autistic children are limited, measurement of ER could include behavioral observation of negative affect and emotional reactivity (17). Consideration of ER could also be given within interventions targeting a wider constellation of social communication skills. Examination of ER alongside social communication outcomes will be particularly important with the overlap in ER and core autistic features (24) and findings that parent scaffolding may change within intervention targeting social communication. Relatedly, it will be important to measure caregiver behaviors that are thought to be related to ER development to better understand whether changes in caregiver responsivity, emotional scaffolding, and/or stress relate to changes in child ER skills. Finally, although there is not yet consensus on factors that moderate outcomes within parent-mediated interventions (80), it may be important to consider ER as a treatment moderator. Its relationship to challenging behaviors and the impact of these types of behaviors on treatment engagement and participation imply relationships to be explored in future studies.

Understanding how evidence-based interventions can proactively support ER skills in young autistic children is integral to enhancing research and practice. There is a growing body of evidence to support the positive impact of parent-mediated interventions on child and family outcomes. Thus, the application of these intervention models in the context of ER may help to build ER skills in very young children while offsetting mental health difficulties. Further, the intertwined relationship between ER, challenging behavior, and social communication provides an opportunity to explore how ER skills may change in response to parent-mediated interventions, the caregiver behaviors that may support these changes (e.g., co-regulation), and the extent to which changes in ER are related to social communication and behavioral outcomes.

Publicly available datasets were analyzed in this study.

NH: coordinated the systematic review, screened and reviewed abstracts and full texts, wrote the results, and edited manuscript. KP: wrote the introduction and discussion, screened and reviewed abstracts and full texts, and edited manuscript. GB: wrote the methods and screened abstracts. EK: conducted reliability for screened abstracts, supported revisions, and supported formatting and references. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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