Blended online behavioral parent training improves parenting skills but shows limited effect on ADHD symptoms in Vietnamese children: RCT

A randomized controlled trial conducted in Vietnam has shown that a culturally adapted blended online behavioral parent training (BPT) program produced large and sustained improvements in parenting skills among parents of children with attention-deficit/hyperactivity disorder (ADHD). However, the program's effects on parent-rated ADHD symptoms were small and did not reach statistical significance, according to findings published in JCPP Advances.

• 86 parents of children (6–11 years) with confirmed ADHD were randomly assigned to a blended online BPT program or treatment as usual plus psychoeducation.

• The intervention included 6 weekly group sessions, 6 individual home-based sessions, and 12 weekly support calls over a 3-month maintenance period.

• Parenting skills improved substantially in the intervention group compared to controls (adjusted between-group d = 1.28 at 3-month follow-up; p < .001).

• Parent-rated ADHD symptoms decreased within the intervention group but between-group differences were not statistically significant (p = .075 at follow-up; adjusted d ≈ 0.28–0.30).

• Exploratory mediation analysis suggested that improved parenting skills may partially mediate reductions in ADHD symptoms.

• The trial was retrospectively registered; findings require replication in larger, adequately powered studies.

Study snapshot

• Design: Two-arm, parallel-group, randomized controlled trial (superiority).

• Population: 86 parents of children aged 6–11 years with a clinician-confirmed DSM-5 diagnosis of ADHD. Conducted in Vietnam.

• Intervention: Blended online BPT: six 2-hour online group sessions plus six 1-hour individual home-based support sessions (one per week for 6 weeks), followed by 12 weekly support telephone calls across a 3-month maintenance period.

• Comparator: Treatment as usual plus psychoeducational materials.

• Primary outcome: Parenting skills (Parenting Skills Assessment Scale).

• Secondary outcomes: Parent-rated child ADHD symptoms (Vanderbilt ADHD Diagnostic Parent Rating Scale); parenting stress.

• Analysis: 80 participants with complete data (intervention n=37, control n=43). Mixed-model repeated measures.

• Key result: Significant group × time interaction for parenting skills (F(2,156)=20.75, p<.001, partial η²=0.21); baseline-adjusted between-group Cohen's d = 1.28 at 3-month follow-up.

• Limitations: Parent-reported outcomes; retrospective registration; moderate attrition in intervention arm; short follow-up.

• Registration: Thai Clinical Trials Registry TCTR20260212003 (retrospective).

What the trial asked

Behavioral parent training is a well-established, evidence-based intervention for children with ADHD, but most studies have been conducted in high-income Western countries. Evidence from low- and middle-income Asian countries, including Vietnam, remains scarce. This trial aimed to evaluate whether a culturally adapted, blended online BPT program—combining group sessions with individual home-based support—could improve parenting skills, reduce ADHD symptoms, and decrease parenting stress among Vietnamese parents of elementary school-aged children with ADHD.

Why the question matters

ADHD is one of the most common neurodevelopmental disorders in childhood, affecting approximately 5–7% of children worldwide. In Vietnam, access to specialized mental health services is limited, and many families face barriers to attending in-person therapy, including stigma, cost, and transportation difficulties. Online and blended interventions have the potential to expand access to evidence-based care in such settings. However, interventions must be culturally adapted to be acceptable and effective. This study addresses a critical gap by testing a program designed specifically for Vietnamese families.

How the study was conducted

Eighty-six parents of children aged 6 to 11 years with a clinician-confirmed DSM-5 diagnosis of ADHD were enrolled at a single center in Vietnam. Participants were randomly assigned in a 1:1 ratio to either the blended BPT program (n=43) or treatment as usual plus psychoeducational materials (n=43).

The intervention consisted of six weekly 2-hour online group sessions, each followed within the same week by a 1-hour individual home-based support session delivered by a trained therapist. After the initial six weeks, participants received 12 weekly telephone support calls across a 3-month maintenance period. The program was culturally adapted to incorporate Vietnamese parenting values, communication styles, and practical strategies for managing ADHD behaviors.

Outcomes were assessed at baseline (T1), immediately post-intervention (T2), and at 3-month follow-up (T3). The primary outcome was parenting skills, measured using the Parenting Skills Assessment Scale. Secondary outcomes included parent-rated child ADHD symptoms (Vanderbilt ADHD Diagnostic Parent Rating Scale) and parenting stress. Analyses were conducted on 80 participants with complete data (intervention n=37, control n=43); six participants in the intervention group were lost to follow-up or withdrew, while none were lost in the control group.

What the trial found

Parenting skills improved substantially in the intervention group relative to the control group. The group × time interaction was statistically significant (F(2,156)=20.75, p<.001, partial η²=0.21, indicating a large effect). The baseline-adjusted between-group Cohen's d was 1.28 at the 3-month follow-up, representing a large effect size.

Parent-rated ADHD symptoms decreased significantly within the intervention group from baseline to follow-up (mean change -4.14 points, p<.001). However, the baseline-adjusted between-group differences were small and not statistically significant. At post-intervention, p=0.057; at follow-up, p=0.075. The adjusted Cohen's d values were approximately 0.28–0.30, indicating small effects.

Parenting stress decreased in both groups, and no significant between-group differences were found. An exploratory mediation analysis revealed a significant indirect effect on follow-up ADHD symptoms through improved parenting skills (indirect effect ab=-1.86, 95% bootstrap confidence interval -4.01 to -0.37), suggesting that enhanced parenting skills may partly explain the reduction in ADHD symptoms observed within the intervention group.

What the results mean

The findings indicate that the culturally adapted blended online BPT program was feasible and highly effective at improving parenting skills, with large effects sustained at 3-month follow-up. The lack of statistically significant between-group differences on parent-rated ADHD symptoms highlights a discrepancy: even though parents in the intervention group reported symptom improvements over time, the control group also showed some improvement (likely due to psychoeducation or natural history), and the between-group comparison did not confirm a clear treatment advantage. The small effect sizes for ADHD symptoms suggest that the program may require additional components—such as child-focused behavioral interventions or medication—to produce clinically meaningful symptom reduction.

The exploratory mediation analysis provides preliminary evidence that improvements in parenting skills might partially mediate reductions in ADHD symptoms, supporting the theoretical underpinning of BPT. However, mediation findings are considered hypothesis-generating and require confirmation in a trial designed to test mediation with adequate statistical power.

Important limitations

The trial has several limitations. First, it was a single-center study with a moderate sample size; the analysis included only 80 of 86 randomized participants, and attrition was limited to the intervention group, which may introduce bias. Second, all outcomes were parent-reported, raising the possibility of reporter bias, particularly since parents in the intervention group were not blind to treatment assignment. Third, the trial was retrospectively registered on the Thai Clinical Trials Registry (TCTR20260212003), which increases the risk of selective outcome reporting. Fourth, follow-up was limited to 3 months; longer-term durability is unknown. Fifth, the study did not include objective measures of child behavior or academic functioning, and no safety data were reported. Finally, the intervention's effects on ADHD symptoms were small and not statistically significant, so claims of efficacy for symptom reduction are not supported by these data.

Implications for patients and clinicians

For clinicians in Vietnam and similar settings, the findings suggest that a blended online BPT program can be a feasible and effective tool for enhancing parenting skills—an important goal in ADHD management. The program may be particularly useful as a first-line psychosocial intervention or as an adjunct to pharmacological treatment. Parents can expect to gain strategies for managing their child's behavior, but the program alone may not produce large reductions in ADHD symptoms. Clinicians should counsel families accordingly and consider combining the program with other evidence-based treatments.

From a public health perspective, this study demonstrates that digital and blended interventions can be successfully adapted to non-Western, lower-resource contexts. However, larger, preregistered trials with blinded outcome assessment, active comparators, and longer follow-up are needed before the program can be broadly recommended for ADHD symptom reduction.

Funding and trial registration

The trial was retrospectively registered on the Thai Clinical Trials Registry (TCTR20260212003, registration number TCTR20260212003). Funding information was not reported in the available source. The study was conducted by researchers from Vietnamese institutions, as indicated by the author list: Nam TT, Tram Anh NT, Hong Nhung NT, Lam LT, Thuy Hang LT.

References

1. Nam TT, Tram Anh NT, Hong Nhung NT, Lam LT, Thuy Hang LT. Effectiveness of a blended online behavioral parent training program for Vietnamese parents of children with ADHD: A randomized controlled trial with 3-month follow-up. JCPP Adv. 2026 Jul 24:e70150. doi:10.1002/jcv2.70150. PMID: 42502624.