Sage Journals: Discover world-class research

Abstract

The objective of this research was to assess the efficacy of behavioral therapy interventions in the treatment of autism spectrum disorders (ASD). The study utilized the PubMed and Embase databases to locate randomized controlled trials, quasi-experimental treatment studies, and randomized clinical trial comparisons. The experimental group received treatment based on an applied behavioral approach, such as PECS, DTT, PRT, TEACCH, ESDM, and EIBI. After examining seventeen studies, the researchers found that each type of behavioral intervention had a positive impact. Naturalistic protocols that employed PRT and PECS improved ASD symptoms in general, despite their targeting of particular cognitive domains such as language. ESDM enhanced receptive language, particularly in preschool-aged children. Structured and integrated interventions, like EIBI and TEACCH, improved overall adaptive functioning. Combining DTT with a TEACCH program produced greater benefits in linguistic, affective-social, and personal autonomy domains. However, there is a scarcity of high-quality research available on behavioral interventions for ASD. Further comparative studies are necessary to identify cost-efficient interventions. For example, PRT and PECS significantly improved social communication skills in only 15–40 hours over six months. The authors emphasized the need for continued research and the application of evidence-based interventions in specialized settings.

Keywords

Effectiveness behavioral interventions autism spectrum disorder systematic review randomized controlled trials

Introduction

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by persistent deficits in social communication and interpersonal interaction in multiple contexts. Common signs of ASD are having a deficit of social-emotional reciprocity, use of non-verbal communication behaviors for social interaction, and insufficiency in the development, management, and understanding of relationships (APA, 2022).

Autism spectrum disorders is a significant public health concern due to its early onset, prolonged duration, and numerous associated impairments (Yu et al., 2020). As a result, various treatments from different theoretical perspectives have been suggested (Howard et al., 2014). In current clinical practice, promising interventions are based on the principles of the behavioral approach (Lovaas, 1987). All forms of behavioral treatment come from the experimental analysis of behavior. This area of science studies the laws that influence people’s behavior in the environment. The continued study and application of these laws to socially significant problems is known as applied behavioral analysis (ABA) (Pervin et al., 2022). In summary, ABA involves the systematic teaching of small measurable units of behavior. The task chosen to be learned is identified based on the development profile, individual choices, and preferences depending on the person. These units are divided into small stages, each of which is taught in repeated and close teaching sessions, according to specific instructions. The student is guided to give simple answers, systematically incorporated into age-appropriate repertoires (learning without errors) through prompts and consequences that function effectively as reinforcement. Therefore, when applied to ASD, ABA focuses on treating the problems of the disorder by altering social environments, identifying the factors that favor preservation over time, and favoring the learning of adaptive and functional behaviors (Pervin et al., 2022). ABA is included among a series of approaches, known as behavioral interventions, which are placed along a continuum that goes from highly structured approaches to environmental ones. The environmental and social approaches are focused on the interests of children and integrated into the children’s daily activities (Howard et al., 2014).

One structured approach is discrete trial training (DTT; Werts et al., 2003). DTT is very popular and a type of behavioral intervention in which skills are taught through a procedure that includes three elements. The first component is the instruction given to the child, also known as the discriminating stimulus (= DS), which constitutes the antecedent stimulus that will lead to the control of behavior. The second component is the child’s response (= R) and the third one is the consequence of the child’s response (reinforcement stimulus = SR) (Leaf et al., 2016).

In the current clinical practice, promising interventions are based on the principles of ABA and developmental strategies – such as naturalistic developmental behavioral interventions (NDBI; Schreibman & Stahmer, 2014). A prominent NDBI with emerging evidence is pivotal response treatment (PRT; Koegel & Koegel, 2006). PRT strategies are child-focused and have a natural rewarding approach to strengthen the child’s motivation for social contact. Implementation procedures include: following the child’s interests, gaining the child’s attention, using clear instructions (prompts), providing immediate and contingent reinforcement in response to a child’s initiation or good attempt, and interspersing maintenance and acquisition tasks. In addition, caregivers are actively involved in the PRT program (de Korte et al., 2021).

Other researchers have emphasized the use of intrinsic motivation as a positive drive for learning. There are two key models utilizing this method. These models are known as the treatment and education of autism and communication handicapped children (TEACCH; Venter et al., 1992) and the early start Denver model (ESDM; Rogers et al., 2012). The TEACCH program stands out for its comprehensive and multidisciplinary approach compared to other treatments. Its goal is to promote independence and social inclusion through structured teaching, as described by Vivanti et al. (2016). On the other hand, the ESDM program is designed specifically for preschool children with ASD, in agreement with Colombi et al. (2018) because it mainly focuses on the development of communication skills and mutual social interaction. This approach involves structured sessions based on DTT, where a specialized operator leads intensive activities according to rigorous procedures (Wong et al., 2015).

Finally, there are competency-based methods that concentrate on particular cognitive fields and functional capabilities. The Picture Exchange Communication System (PECS; Bondy & Frost, 1998) is a prime example of this and can be incorporated into integrated techniques or used alone to improve communication abilities (Lerna et al., 2012, 2014).

Despite this knowledge, scientific evidence is not always consistent in describing the effectiveness of these treatments and requires further supporting evidence. For instance, the most recent meta-analysis (Yu et al., 2020) analyzing 14 randomized control trials in which 555 participants were included revealed significant outcomes on socialization, communication, and expressive language due to the adoption of ABA-based interventions (i.e., ESDM, PECS, and DTT). Nonetheless, significant effects for the outcomes of autism general symptoms, receptive language, adaptive behavior, daily living skills, verbal and non-verbal intelligence quotient, restricted and repetitive behavior, and motor and cognition were not reported by Yu and colleagues. Our study aimed to replicate the systematic literature review including the most recent studies. Furthermore, another goal was to highlight whether there were different outcomes between various behavioral interventions compared to each other.

Methods

Information sources and search strategy

The following databases were searched: Pubmed, Medline, Embase, and PsycInfo. The main keywords utilized in the article searches included the following: autism spectrum disorder, autism, autistic disorder, ASD; behavioral interventions, behavior therapy; applied behavior analysis, ABA; picture exchange communication system, PECS; discrete trial teaching, DTT; pivotal response treatment, PRT; treatment and education of autistic and communication handicapped children, TEACCH; early start Denver model, ESDM; early intensive behavioral intervention, EIBI. The search considered the title and abstract or topic and included only journals in English. Finally, the search was limited by date: the databases were searched considering the last 10 years.

Eligibility criteria and study selection

Studies were included if they met the following criteria: (1) the study should be a randomized controlled trial (RCT), a quasi-experimental treatment study, or a randomized clinical trial comparison; (2) participants were between the ages of 0 and 18 years old; (3) participants were diagnosed with ASD and their symptomatology was measured by a recognized scale (i.e., ADOS: Autism Diagnostic Observation Scale); (4) the treatment used in the experimental group was part of the behavioral interventions (ABA, PECS, DTT, PRT, TEACCH, ESDM, EIBI); (5) the treatment used in the control group was traditional intervention (i.e., conventional language therapy, parental guidance, intensive family therapy, and social skill training); (6) the study included at least one standardized continuous outcome measure related to autistic manifestations. Studies were excluded if they (1) were qualitative, reviews, meta-analyses, case studies, theses, dissertations, or conference presentations; (2) did not specifically measure the symptomatology of ASD; (3) did not administer a form of behavioral intervention (ABA, PECS, DTT, PRT, TEACCH, ESDM, EIBI).

Selection of outcome measures

The general symptomatic outcomes of ASD, including socialization outcomes, communication outcomes, expressive language outcomes, receptive language outcomes, adaptive behavior outcomes, daily living skills outcomes, and intelligence quotient outcomes, were selected in this study.

Results

Study selection

Figure 1 presents the PRISMA chart that shows the results of the search. The search across databases produced 1,478 records. After removing 698 duplicates, 789 records were screened based on the title and abstract, 673 of which were excluded. 116 full-text articles were assessed for eligibility and 99 of them were excluded. The reasons were: 63 were excluded because of the absence of a control group; 1 study could not provide full text after contacting the author; 9 studies did not meet the requirement for participants; 25 studies did not include relevant outcomes; and 1 study did not adequately describe the procedure of the implemented treatments. Finally, 17 randomized controlled trials, quasi-experimental treatment studies, and randomized clinical trial comparison studies were included in this review.

Figure 1.

Flow diagram of study selection.

Among these, a distinction was made considering the type of condition of the control group from study to study. Table 1 summarizes the studies that evaluate an experimental group (behavioral intervention) compared to a control group (subjected to a traditional intervention or on a waitlist). Instead, Table 2 encapsulates grouped research that compared the effectiveness of several types of behavioral intervention.

Table 1.

A summary of controlled studies characteristics.

Authors	Experimental design	Exp. (n = )	Cont. (n = )	Age (range)	Intervention	Exp. dosage	Location	Measurement	Outcome
Lerna et al. (2012), (2014)	Quasi-experimental	7	7	18–60 months old	PECS	72 30-min sessions in 6 months	Center-based	GMDS, ADOS, VABS II	Time × group effect in the VABS social area (F (1, 16) = 10.519, p = .005), during free-play (cooperative play (F (1, 16) = 7.648, p = .014); joint attention (F (1, 16) = 7.993, p = .012); requests (F (1, 16) = 4.797, p = .044); initiation (F (1, 16) = 7.562, p = .014)) in the 2012 study. Time × group effects in the ADOS test (Communication: F (1, 36) = 15.34, p = .0001; social: F (1, 36) = 8.41, p = .006; Total score: F (1, 36) = 14.59, p = .001) and the personal-social score of GMDS test (F (1, 36) = 9.95, p = .003) in the 2014 study (follow-up).
Duifhuis et al. (2017)	Quasi-experimental	11	13	3–8 years old	PRT	20 45-min sessions in 6 months	Centre-based	ADOS, SRS, CBCL, NOSI‐K, WPPSI or WISC	Time per group effect revealed that PRT group improved ADOS scores (F = 3.974, p = .059).
Vernon et al. (2019)	RCT	16	12	18–56 months	PRISM	10 hrs per week for 6 months	Preschool- and community-based	ADOS-2, MSEL, PLS-5, PPVT-4, EVT-2, VABS-II	Time effect for the severity of symptoms (ADOS-2-Calibrated severity score, t = −4.31, p = .001) and the impairment of language skills (MSEL-expressive language, t = 4.97, p = .000; PLS-5-total score, t = 2.56, p = .026; PPVT-4-standard score, t = 3.51, p = .006) for the PRISM group. In addition, time effect was observed in the PRISM group on the MSEL of visual reception (t = 2.29, p = .042), fine motor (t = 3.16, p = .009), and receptive language (t = 3.42, p = .006), as well as the VABS-II communication subdomain (t = 2.57, p = .028).
de Korte et al. (2021)	RCT	22	22	9–15 years old	PRT	7 parent–child sessions, 3 parent-only sessions, and 2 teacher-child in 12 months	Multiple setting	SRS, CGI-I, BPM-P, OBVL, ADOS-2, VABS-II	Time × group effect on SRS-Total score (F (1, 34) = 9.62, p = .004). Significant group differences in the VABS-II-socialization sub-scale (U = 99.500, p = .002) and in the BPM-P (U = 125.000, p = .042) post-intervention.
Ichikawa et al., (2013)	RCT	5	6	5-6 years old	TEACCH	2 hrs per week for 6 months	Community-based (group)	SDQ, PSI, BDI-II, IRS	Group effect in SDQ (−3.12, effect size = .71), PSI (−18.12, effect size = .58, BDI-II (−2.77, effect size = .40) at the endpoint.
D’Elia et al. (2014)	Quasi-experimental	15	15	2.0–6.11 years old	TEACCH	2 hrs at home + 2 hrs at school per week for 24 months	Home-school based	ADOS, CDI, VABS, CBCL, PSI, PEP-3	Significant effects in the CBCL for withdrawal (time: p = .002, group: p = .001), pervasive developmental (time: p = .044, group: p = .025), attention Deficit/hyperactivity (group: p = .010), internalizing problems (time: p = .003, group: p = .046), and Total problems (time: p = .001, group: p = .045) and in the PSI (time: p = .005, group = .009) after the intervention.
Nowell et al. (2019)	Quasi-experimental	8	10	6–8 years old	TEACCH	90 minutes per week for 2.5 months	Community-based	COP, PROGO, 3-Box task	Time × group effect in the COP scales of social Thinking (F (1, 15) = 4.78, p = .05) and total score (F (1, 15) = 6.90, p = .02) and at the follow-up at 3-months (F (2, 13) = 4.81, p ≤ .03) as well as at 6 months (F (3, 10) = 3.40, p ≤ .04). Time × group effect also for the PROGO total scale (F (1, 15) = 7.06, p ≤ .02) and the self-regulation (F (1, 15) = 6.10, p ≤ .03) and parent detachment (F (1, 15) = 4.85, p ≤ .04) sub scales.
Vivanti et al. (2014)	Quasi-experimental	27	30	2.5–6 years old	ESDM	15–25 hrs per week for 12 months	Community-based (Group)	MSEL, VABS-II, ADOS	Time × group effect in developmental rates and receptive language development (F (1, 55) = 4.48, p < .05).
Colombi et al. (2018)	Quasi-experimental	22	70	18–48 months old	ESDM	2 hrs per week for 6 months	Community-based	GMDS, VABS-II	Time × group effect on the GMDS-total score at 3 months (F = 2.0, p = .03) and at 6 months (F = 2.3, p = .02). Group difference on the GMDS-personal social sub scale at 3 months (F = 2.0, p = .04) and at 6 months (F = 4.0, p < .01), and on the GMDS-hearing and speech sub scale at 3 months (F = 22.4, p = .01) and at 6 months (F = 2.1, p = .03). Group differences also found in the VABS composite at the 3-months period (ESDM group showed an improvement of 7.9 points in comparison to baseline, whereas the TAU group showed an improvement of 3.5 points (F = 2.1, p = .03). Group difference for the VABS communication subscale (F = 2.8, p < .01) at 3 months.
Waters et al. (2020)	Quasi-experimental	48	46	18–75 months	EIBI	35–40 hr per week for 36 months	Community-based	WPPSI-R/WPPSI-III or WISC-III/WISC-IV, VABS	Time effect on the NVIQ with an increase in .234 points in the EIBI group per month with a group effect after treatment (EIBI vs. SAU, p < .05). Time-by-treatment interaction significant for all VABS scales (composite VABS score increases .454 points per month, p < .01; communication levels increase .511 points per month, p < .01; daily living increases .384 points per month, p < .01; and socialization increases .276 points per month, p < .01).

Notes: ADOS = Autism Diagnostic Observation Scale; ADOS-2 = Autism Diagnostic Observation Schedule‐Second Edition; BDI-II = Beck Depression Inventory-II; BPM-P = Brief Problem Monitor‐Parents; CBCL1.5–5 = Child Behavior Checklist; CDI = MacArthur Communication Developmental Inventories; CGI-I = Clinical Global Impression‐Improvement; Cont. = Control; COP: Child Observation Protocol; EIBI = Early Intensive Behavioral Intervention; ESDM = Early Start Denver Model; EVT-2: Expressive Vocabulary Test; Exp. = Experimental; GMDS: Griffiths Mental Development Scales; IRS: Interaction Rating Scale; MSEL: Mullen Scales of Early Learning; NOSI‐K: Nijmegen Parental Stress Index-Short Version; OBVL: Parenting Stress Questionnaire; PECS = Picture Exchange Communication System; PEP-3: Psychoeducational Profile-Third Edition; PLS-5: Preschool Language Scales, 5th Edition; PPVT-4: Peabody Picture Vocabulary Test; PRISM = PRT for Social Motivation; PRT = Pivotal Response Treatment; PROGO: Parent Report of Group Outcomes; PSI: Parenting Stress Index; PSI-SF: Parenting Stress Index-Short Form; SDQ: Strengths and Difficulties Questionnaire; RCT = Randomized Controlled Trial; SRS: Social Responsiveness Scale; TEACCH = Treatment and Education of Autistic and Communication Handicapped Children; VABS-II: Vineland Adaptive Behavior Scales, Second Edition; WISC-III: Wechsler Intelligence Scales for Children Third Edition; WISC-IV: Wechsler Intelligence Scales for Children Fourth Edition; WPPSI-R: Wechsler Preschool and Primary Scale of Intelligence Revised; WPPSI-III: Wechsler Preschool and Primary Scale of Intelligence-Third Edition.

Table 2.

A summary of comparative studies characteristics.

Authors	Experimental design	Group 1 (n = , type, dosage)	Group 2 (n = , type, dosage)	Group 3 (n = , type, dosage)	Age (range)	Location	Measurement	Outcome
Stanislaw et al. (2020)	Quasi-experimental	50 ABA (25–40 hrs per week for 50 months)	32 Eclectic treatment (10 hrs ABA + speech therapy and/or occupational therapy)	—	11–90 months	Multiple setting	BSID, RDLS, VABS, WISC/WIPPSI, ROWPVT or EOWPVT	Time effect observed only for the ABA group on the VABS (cognitive: p = .008; expressive: p = .001; receptive: p = .015; adaptive composite: p = .009; self-help: p = .007; and communication: p = .048).
Mohammadzaheri et al. (2014)	RCT Comparison	15 ABA (60 min twice a week for 3 month)	15 PRT (60 min twice a week for 3 month)	—	6–11 years old	School-based	CCC	Time x group effect (PRT>ABA) on the MLU (F (1,27) = 6.97, p = .01) and on the CCC (F (1, 26) = 6.38, p = .01) after 3 months.
Schreibman & Stahmer (2014)	RCT Comparison	19 PECS (181–263 hrs in total in 6 months)	20 PRT (181–263 hrs in total in 6 months)	—	20–45 months old	Home-based	MSEL, EOWPVT, CDI, VABS	Time effect within each treatment on MSEL-expressive communication (F (1,28) = 9.95, p = <.001), CDI-Words pronounced index (F (1,28) = 31.26, p = .000), VABS-Communication sub-scale (F (1,28) = 4.09, p = .037).
Sinai-Gavrilov et al. (2020)	Quasi-experimental	26 ESDM (44 hrs per week for 8 months)	25 Multidisciplinary developmental intervention (ABA/DIR/TEACCH/psychodynamic) (44 hrs per week for 8 months)	—	33–57 months old	Preschool-based	MSEL, VABS-2	Time x group effect (ESDM > MDI) on the MSEL-Cognitive functioning (F (1,45) = 7.52, p < .01), MSEL-receptive language (F (1,45) = 9.68, p < .01), and MSEL-expressive language (F (1,45) = 4.55, p < .05). Time x group effect (ESDM > MDI) observed also on the parent-reported VABS-II-socialization domain (F (1,45) = 5.72, p < .05) and on the teacher-reported VABS-II-Communication domain (F (1,45) = 5.47, p < .05).
Zeng et al. (2021)	RCT Comparison	30 DTT (30-min session, 5 days a week, for 6 months)	30 DTT + TEACCH (the same as the DTT group + 30-min session, 5 days a week, for 6 months of TEACCH)	—	36–90 months old	Community-based	CPEP-3	Time x group effects (DTT + TEACCH > DTT) on the CPEP-3 expressive language (F = 4.546, p < .05), receptive language (F = 3.979, p < .05), fine motor (F = 7.122, p < .01), affective expression (F = 6.407, p < .01), social reciprocity (F = 4.906, p < .05), problem behavior (F = 6.786, p < .01), and personal self-care (F = 7.636, p < .01) sub scales. Group differences confirmed at the six-month follow-up on the CPEP-3 expressive language (t = 2.180, p < .05), affective expression (t = 2.549,p < .05), social reciprocity (t = 2.065, p < .05), problem behavior (t = 2.860, p < .01), and personal self-care (t = 2.897, p < .01) sub scales.
Mazza et al. (2021)	Quasi-experimental	31 ABA (4 hrs daily for 5 days a week for 5-6 months)	37 TEACCH (4 hrs daily for 5 days a week for 5–6 months)	26 BEI (4 hrs daily for 5 days a week for 5–6 months)	12–18 years old	ABA: Home + school; TEACCH: Semi-residential rehabilitation centre; BEI: Semi-residential rehabilitation centre + active life context	ADOS-2, VABS-II, CPM, TROG-2	Time effect for all participants on ADOS-2-social affect (F (2,92) = 105.12, p < .01), restricted and repetitive Behaviour (F (2,92) = 20.73, p < .001), and Total score (F (2,92) = 84.36, p < .01). Time effect for all the participants on VABS-II sub scales: Receptive (F (2,91) = 12.14, p < .01); Community (F (2,91) = 7.01, p < .01); daily living skills (F (2,91) = 18.23, p < .01); and social rules (F (2,91) = 41.36, p < .01) without interaction effect. Group effect at the end of treatment for interpersonal relationship (F (2,91) = 6.50, p < .01; post hoc: TEACCH > ABA: M_dif = −.99, SE = .34, p = .01), expressive (F (2,91) = 5.06, p < .01; post hoc BEI > ABA: M_dif = −1.69, SE = .54, p < .01), writing (F (2,91) = 3.22, p = .04; post hoc BEI > ABA: M_dif = −1.69, SE = .68, p = .04), person (F (2,91) = 7.73, p < .01; post hoc BEI > ABA: M_dif = −2.05, SE = .57, p < .01; BEI > TEACCH: M_dif = −1.84, SE = .55, p < .01) and domestic (F (2,91) = 5.98, p < .01, post hoc BEI > ABA: M_dif = −2.15, SE = .68, p < .01; BEI > TEACCH: M_dif = −1.98, SE = .66, p = .01) sub scales of the VABS-II.

Notes: ABA = Applied Behavior Analysis; ADOS: Autism Diagnostic Observational Schedule; ADOS-2: Autism Diagnostic Observational Schedule-2nd edition; BEI = Behavioral Educational Intervention; BSID: Bayley Scales of Infant Development-2nd edition; CARS: Childhood Autism Rating Scale; CCC: Children’s Communication Checklist; CPEP-3: Chinese version of the Psycho-educational Profile-3ard edition; CPM: Raven’s Coloured Progressive Matrices test; DIR = developmental, individual difference, relationship-based; DTT = Discrete Trial Teaching; EOWPVT: Expressive One-Word Picture Vocabulary Test; ESDM = Early Start Denver Model; LIPS-R: Leiter International Performance Scale-Revised; MSEL: Mullen Scales of Early Learning; PECS = Picture Exchange Communication System; PICS: Pictorial Infant Communication Scales; PLS-4: Pre-school Language Scales-4th Edition; RBS-R: Repetitive Behavior Scales-Revised; RCT = Randomized Controlled Trial; RDLS: Reynell Developmental Language Scales; ROWPVT: Receptive One-Word Picture Vocabulary Test; SCQ: Social Communication Questionnaire; SRS: Social Responsiveness Scale; TROG-2: Test for Reception of Grammar-2nd edition; VABS-SE: Vineland Adaptive Behavior Scales-Survey Edition; VABS-II: Vineland Adaptive Behavior Scales-2nd edition.

Study characteristics

The local Institutional Review Board approved all the studies, informed consent was obtained from the participants’ parents.

A summary of the characteristics of the studies can be found in Table 1 and Table 2.

Discussion

We reviewed DTT, PRT, TEACCH, ESDM, EIBI, and PECS interventions to evaluate the effectiveness of these types of approaches on children with ASD. By excluding studies with single group pretest-posttest design and single case studies, this work aimed to identify and evaluate the effectiveness of controlled clinical trials, both RCT and non-randomized or quasi-experimental trials. All the studies that compared the scores of an experimental group with those of a control group were included. Subsequently, controlled studies (n = 11) were distinguished from comparative ones (n = 7). When only examining the controlled studies, the control group received typical treatment methods such as conventional language therapy, parental guidance, intensive family therapy, and social skill training. However, in two of these studies, the control subjects were the same as those on the waitlist. The varying impacts of diverse behavioral therapies are emphasized in the comparative studies. We observed significant effects for general and specific outcomes regarding expressive and receptive language, adaptive behavior, and daily living skills as well as social area skills. For instance, the use of PECS is a technique that only enhances the language domain, yet Lerna et al. (2012, 2014) described positive effects on the overall social area investigated. On top of this, a general improvement in the child’s symptoms and global profile based on the ADOS and Griffiths Mental Development Scales (GMDS) scales was described at the end of the treatment as well as at the follow-up. Anyhow, for an in-depth analysis of the research studies involving the efficacy of all of the programs with Assisted Augmented Communication (AAC) see Ganz (2015 1985), because in our work they have not been included. Significant improvements in overall functioning have also been described by Waters et al. (2020) implementing EIBI. These authors found a significant increase in the global intelligence quotient (IQ) and non-verbal intelligence quotient (NVIQ), underlining the strong impact of the intervention on adaptive behavior. Similar results have also been described by Vivanti et al. (2014) and Colombi et al. (2018) with the application of ESDM. These researchers described an improvement in cognitive functioning but only at the level of receptive language. PRT, like EIBI, involves caregivers of children with ASD and has a positive impact on participants' overall profile. In particular, a significant decrease in symptoms detected through the ADOS and a considerable increase in communication skills, assessed through the Preschool Language Scales (5th Edition, PLS-5), Peabody Picture Vocabulary Test (4th Edition, PPVT-4), and Mullen Scales of Early Learning (MSEL), were observed when implementing PRT (Duifhuis et al., 2017; Vernon et al., 2019). Furthermore, the PRT intervention favored the development of visuospatial and fine-motor skills (Vernon et al., 2019) as well as social skills (Vernon et al., 2019; de Korte et al., 2021). Moreover, Nowell et al. (2019) discovered that also the TEACCH approach yielded favorable outcomes in emotional and relational abilities. Additionally, D'Elia et al. (2014) noted enhancements in withdrawal, internalizing symptoms, and pervasive developmental issues among the cohort of children who underwent TEACCH treatment.

In short, the comparative analysis showed that all of the behavioral methods (PECS, EIBI, ESDM, PRT, and TEACCH) are effective in improving social-communicative and linguistic skills. Furthermore, PECS and PRT had direct effects on the cardinal symptoms of the disorder (Schreibman & Stahmer, 2014), while other therapies (EIBI and TEACCH) further enhanced the global adaptive functioning (Mazza et al., 2021). Likewise, comparative studies have highlighted the greater efficacy of intensive interventions. For instance, Zeng et al. (2021) underlined that participants benefit in the linguistic, affective-social, and personal autonomy domains by adding a TEACCH and a DTT intervention to their therapy programs. Similarly, Stanislaw et al. (2020) proved that a highly intensive ABA intervention potentiates the effects on language and social-communicative skills in comparison with a low-intensity ABA treatment combined with other methods. Mazza and colleagues (2021) as well as Sinai-Gavrilov et al. (2020) demonstrated that early behavioral intervention favors the improvement of language skills and interpersonal relational skills as well as the learning of both personal and domestic autonomy.

The authors aimed to highlight effective treatment options and encourage further exploration. One notable finding was that certain behavioral therapies, such as PRT and PECS, which only require 15–40 hours over 6 months, can still significantly improve communication abilities and social engagement. By incorporating these cost-efficient interventions grounded in behavior analysis principles, a foundation can be laid for broader acceptance of such therapies.

Conclusions

In recent years, there has been a significant increase in research focused on conducting randomized controlled trials (RCT). Notwithstanding, our review has revealed that only a handful of studies meet the quality standards due to concerns surrounding low methodological rigor. Consistent with the findings of Sandbank et al. (2020), only 30% of these studies are controlled. Conducting a high-quality study is challenging, involving data collection, protocol compliance, and treatment adherence (Keenan et al., 2010). Nonetheless, behavioral treatments have manifested their effectiveness, and it is crucial to make them more widely available. As such, we strongly urge greater efforts toward applying therapies founded on behavioral principles, which would give ASD patients and their families access to evidence-based treatments.

Footnotes

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.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Sara Guidotti

Data Availability Statement

The presented in this study are available upon reasonable request from the corresponding author.

Appendix

Author biographies

Carlo Pruneti is an Associate Professor of clinical psychology at the Department of Clinical and Experimental Medicine, and coordinator of the Clinical Psychology, Clinical Neuropsychology, and Clinical Psychophysiology, University of Parma. Carlo is a cognitive behavioral psychotherapist, President of the second-level Master's in “Clinical Psychology: Assessment and Counseling - Client-Centered” and Vice President of Italy Sun Moon University, South Korea. He is also the Coordinator of the Scientific Committee of the Italian Association of Analysis and Modification of Behaviour and Cognitive Behavioural Therapy (AIAMC), teacher and supervisor of the AIAMC schools.

Gabriella Coscioni graduated from Boston College and completed a year abroad at the University of Parma. From teaching English to elementary students living in Krobo, Ghana to conducting a senior thesis at Boston College, she is recognized for possessing a strong passion for teaching and learning within a community of other academics. She is working as an RBT at Journey Autism & Behavioral Care Centers in Boston, MA.

Sara Guidotti is a Psychologist annotated in the Emilia Romagna Register (n.9494). She graduated with honors in Psychobiology and Cognitive Neuroscience at the University of Parma, currently a Ph.D. student at the Clinical Psychology, Clinical Psychophysiology, and Clinical Neuropsychology Laboratories of the Department of Medicine and Surgery of the University of Parma. She is a subject scholar for the disciplinary sector of Clinical Psychology (PSI/08) and a teaching tutor for Psychology students at Boston College (Massachusetts, USA). She specialized in deep progressive muscle relaxation and Biofeedback, obtaining the certification for Level I Biofeedback (Biofeedback Federation of Europe) and HeartMath Certified Practitioner (HeartMath Institute).

References

American Psychiatric Association . (2022). The Diagnostic and Statistical Manual of Mental Disorders, Fifth Editing, Text revision (DSM-5-TR). American Psychiatric Association Publishing.

Bondy

A. S.

Frost

L. A.

(1998). The picture exchange communication system. Seminars in Speech and Language, 19(4), 373–388. https://doi.org/10.1055/s-2008-1064055

Colombi

Narzisi

Ruta

Cigala

Gagliano

Pioggia

Siracusano

Rogers

S. J.

Muratori

Prima Pietra Team (2018). Implementation of the early start Denver model in an Italian community. Autism: The International Journal of Research and Practice, 22(2), 126–133. https://doi.org/10.1177/1362361316665792

de Korte

M. W. P.

van den Berk-Smeekens

Buitelaar

J. K.

Staal

W. G.

van Dongen-Boomsma

(2021). Pivotal response treatment for school-aged children and adolescents with autism spectrum disorder: A randomized controlled trial. Journal of Autism and Developmental Disorders, 51(12), 4506–4519. https://doi.org/10.1007/s10803-021-04886-0

D'Elia

Valeri

Sonnino

Fontana

Mammone

Vicari

(2014). A longitudinal study of the teacch program in different settings: The potential benefits of low intensity intervention in preschool children with autism spectrum disorder. Journal of Autism and Developmental Disorders, 44(3), 615–626. https://doi.org/10.1007/s10803-013-1911-y

Duifhuis

E. A.

den Boer

J. C.

Doornbos

Buitelaar

J. K.

Oosterling

I. J.

Klip

(2017). The effect of pivotal response treatment in children with autism spectrum disorders: A non-randomized study with a blinded outcome measure. Journal of Autism and Developmental Disorders, 47(2), 231–242. https://doi.org/10.1007/s10803-016-2916-0

Ganz

J. B.

(2015). AAC interventions for individuals with autism spectrum disorders: State of the science and future research directions. Augmentative and Alternative Communication (Baltimore, Md, 1985), 31(3), 203–214. https://doi.org/10.3109/07434618.2015.1047532

Howard

J. S.

Stanislaw

Green

Sparkman

C. R.

Cohen

H. G.

(2014). Comparison of behavior analytic and eclectic early interventions for young children with autism after three years. Research in Developmental Disabilities, 35(12), 3326–3344. https://doi.org/10.1016/j.ridd.2014.08.021

Ichikawa

Takahashi

Ando

Anme

Ishizaki

Yamaguchi

Nakayama

(2013). TEACCH-based group social skills training for children with high-functioning autism: a pilot randomized controlled trial. BioPsychoSocial Medicine, 7(1), 14. https://doi.org/10.1186/1751-0759-7-14

10.

Keenan

Dillenburger

Moderato

Röttgers

H. R.

(2010). Science for sale in a free market economy: But at what price? ABA and the treatment of autism in Europe. Behavior and Social Issues, 19(1), 126–143. https://doi.org/10.5210/bsi.v19i0.2879

11.

Koegel

R. L.

Koegel

L. K.

(2006). Pivotal response treatments for autism: Communication, social, and academic development. Paul H. Brookes Publishing.

12.

Leaf

J. B.

Cihon

J. H.

Leaf

McEachin

Taubman

(2016). A progressive approach to dis- crete trial teaching: Some current guidelines. Interna-tional Electronic Journal of Elementary Education, 9(2), 361–372.

13.

Lerna

Esposito

Conson

Massagli

(2014). Long-term effects of PECS on social-communicative skills of children with autism spectrum disorders: A follow-up study. International Journal of Language & Communication Disorders, 49(4), 478–485. https://doi.org/10.1111/1460-6984.12079

14.

Lerna

Esposito

Conson

Russo

Massagli

(2012). Social-communicative effects of the picture exchange communication system (PECS) in autism spectrum disorders. International Journal of Language & Communication Disorders, 47(5), 609–617. https://doi.org/10.1111/j.1460-6984.2012.00172.x

15.

Lovaas

O. I.

(1987). Behavioral treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting and Clinical Psychology, 55(1), 3–9. https://doi.org/10.1037//0022-006x.55.1.3

16.

Mazza

Pino

M. C.

Vagnetti

Filocamo

Attanasio

Calvarese

Valenti

(2021). Intensive intervention for adolescents with autism spectrum disorder: Comparison of three rehabilitation treatments. International Journal of Psychiatry in Clinical Practice, 25(1), 28–36. https://doi.org/10.1080/13651501.2020.1800042

17.

Mohammadzaheri

Koegel

L. K.

Rezaee

Rafiee

S. M.

(2014). A randomized clinical trial comparison between pivotal response treatment (PRT) and structured applied behavior analysis (ABA) intervention for children with autism. Journal of Autism and Developmental Disorders, 44(11), 2769–2777. https://doi.org/10.1007/s10803-014-2137-3

18.

Nowell

S. W.

Watson

L. R.

Boyd

Klinger

L. G.

(2019). Efficacy study of a social communication and self-regulation intervention for school-age children with autism spectrum disorder: A randomized controlled trial. Language, Speech, and Hearing Services in Schools, 50(3), 416–433. https://doi.org/10.1044/2019_LSHSS-18-0093

19.

Pervin

Ahmed

H. U.

Hagmayer

(2022). Effectiveness of interventions for children and adolescents with autism spectrum disorder in high-income vs. lower middle-income countries: An overview of systematic reviews and research papers from LMIC. Frontiers in Psychiatry, 13, 834783. https://doi.org/10.3389/fpsyt.2022.834783

20.

Rogers

S. J.

Estes

Lord

Vismara

Winter

Fitzpatrick

Guo

Dawson

(2012). Effects of a brief early start Denver model (ESDM)-based parent intervention on toddlers at risk for autism spectrum disorders: A randomized controlled trial. Journal of the American Academy of Child & Adolescent Psychiatry, 51(10), 1052–1065. https://doi.org/10.1016/j.jaac.2012.08.003

21.

Sandbank

Bottema-Beutel

Crowley

Cassidy

Dunham

Feldman

J. I.

Crank

Albarran

S. A.

Raj

Mahbub

Woynaroski

T. G.

(2020). Project AIM: Autism intervention meta-analysis for studies of young children. Psychological Bulletin, 146(1), 1–29. https://doi.org/10.1037/bul0000215

22.

Schreibman

Stahmer

A. C.

(2014). A randomized trial comparison of the effects of verbal and pictorial naturalistic communication strategies on spoken language for young children with autism. Journal of Autism and Developmental Disorders, 44(5), 1244–1251. https://doi.org/10.1007/s10803-013-1972-y

23.

Sinai-Gavrilov

Gev

Mor-Snir

Vivanti

Golan

(2020). Integrating the Early Start Denver Model into Israeli community autism spectrum disorder preschools: Effectiveness and treatment response predictors. Autism: The International Journal of Research and Practice, 24(8), 2081–2093. https://doi.org/10.1177/1362361320934221

24.

Stanislaw

Howard

Martin

(2020). Helping parents choose treatments for young children with autism: A comparison of applied behavior analysis and eclectic treatments. Journal of the American Association of Nurse Practitioners, 32(8), 571–578. https://doi.org/10.1097/JXX.0000000000000290

25.

Venter

Lord

Schopler

(1992). A follow-up study of high-functioning autistic children. The Journal of Child Psychology and Psychiatry and Allied Disciplines, 33(3), 489–507. https://doi.org/10.1111/j.1469-7610.1992.tb00887.x

26.

Vernon

T. W.

Holden

A. N.

Barrett

A. C.

Bradshaw

J. A.

McGarry

E. S.

Horowitz

E. J.

Tagavi

D. M.

German

T. C.

(2019). A pilot randomized clinical trial of an enhanced pivotal response treatment approach for young children with autism: The PRISM model. Journal of Autism and Developmental Disorders, 49(6), 2358–2373. https://doi.org/10.1007/s10803-019-03909-1

27.

Vivanti

Dissanayake

Victorian ASELCC Team . (2016). Outcome for children receiving the early start Denver model before and after 48 months. Journal of Autism and Developmental Disorders, 46(7), 2441–2449. https://doi.org/10.1007/s10803-016-2777-6

28.

Vivanti

Paynter

Duncan

Fothergill

Dissanayake

Rogers

S. J.

(2014). Effectiveness and feasibility of the early start Denver model implemented in a group-based community childcare setting. Journal of Autism and Developmental Disorders, 44(12), 3140–3153. https://doi.org/10.1007/s10803-014-2168-9

29.

Waters

C. F.

Amerine Dickens

Thurston

S. W.

Smith

(2020). Sustainability of early intensive behavioral intervention for children with autism spectrum disorder in a community setting. Behavior Modification, 44(1), 3–26. https://doi.org/10.1177/0145445518786463

30.

Werts

M. G.

Caldwell

N. K.

Wolery

(2003). Instructive feedback: Effects of a presentation variable. The Journal of Special Education, 37(2), 124–133. https://doi.org/10.1177/00224669030370020601

31.

Wong

Odom

S. L.

Hume

K. A.

Cox

A. W.

Fettig

Kucharczyk

Brock

M. E.

Plavnick

J. B.

Fleury

V. P.

Schultz

T. R.

(2015). Evidence-based practices for children, youth, and young adults with autism spectrum disorder: A comprehensive review. Journal of Autism and Developmental Disorders, 45(7), 1951–1966. https://doi.org/10.1007/s10803-014-2351-z

32.

Liang

(2020). Efficacy of interventions based on applied behavior analysis for autism spectrum disorder: A meta-analysis. Psychiatry investigation, 17(5), 432–443. https://doi.org/10.30773/pi.2019.0229

33.

Zeng

Liu

Huang

Zhou

Tang

Xie

Chen

Yang

B. X.

(2021). Effect of the TEACCH program on the rehabilitation of preschool children with autistic spectrum disorder: A randomized controlled trial. Journal of Psychiatric Research, 138, 420–427. https://doi.org/10.1016/j.jpsychires.2021.04.025

Evaluation of the effectiveness of behavioral interventions for autism spectrum disorders: A systematic review of randomized controlled trials and quasi-experimental studies

Abstract

Keywords

Introduction

Methods

Information sources and search strategy

Eligibility criteria and study selection

Selection of outcome measures

Results

Study selection

Study characteristics

Discussion

Conclusions

Footnotes

Declaration of conflicting interests

Funding

ORCID iD

Data Availability Statement

Appendix

Author biographies

References