Effectiveness of social skills education and sandplay therapy for children with attention deficit hyperactivity disorder and comorbid anxiety

Abstract

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder in school-aged children, often complicated by comorbid anxiety that exacerbates core symptoms and hinders clinical outcomes. Conventional behavioral interventions primarily target external behaviors but inadequately address internalizing issues such as anxiety. Social skills education enhances interpersonal competence, while sandplay therapy facilitates nonverbal emotional expression. We hypothesize that combining these approaches may simultaneously improve behavioral symptoms and emotional distress, offering a comprehensive non-pharmacological intervention for children with ADHD and comorbid anxiety.

AIM

To investigate the efficacy of social skills education combined with sandplay therapy for children with ADHD and comorbid anxiety.

METHODS

Fifty-two children with ADHD and comorbid anxiety were randomly assigned to either a control group receiving routine training or an observation group receiving social skills education and sandplay therapy for 12 weeks. Pre-intervention and post-intervention assessments included the Conners Parent Symptom Questionnaire, Swanson Nolan and Pelham-IV rating scales, Social Anxiety Scale for Children, Screen for Child Anxiety Related Disorders, Piers-Harris Children’s Self-Concept Scale, and number cancellation test. Parental satisfaction was compared.

RESULTS

After 12 weeks of intervention, the observation group showed significantly lower scores than the control group in the Parent Symptom Questionnaire (hyperactivity index, anxiety, conduct problems, psychosomatic problems, hyperactivity/impulsivity factor), Swanson Nolan and Pelham-IV (attention deficit, hyperactivity/impulsivity, oppositional defiantness), and Social Anxiety Scale for Children and Screen for Child Anxiety Related Disorders scales (all P < 0.05). The observation group also showed significantly higher scores than the control group in the Piers-Harris Children’s Self-Concept Scale (physical appearance and attributes, anxiety dimension) and digit cancellation test (number of correct digits crossed out, number of incorrect digits crossed out, and number of missed digits crossed out) (all P < 0.05). Parental satisfaction was significantly higher in the observation group than in the control group (P < 0.05).

CONCLUSION

Social skills education with sandplay therapy may improve core symptoms and anxiety in children with ADHD, enhance attention and self-awareness, and achieve parental satisfaction, suggesting clinical potential.

Key Words: Social skills education; Sandplay therapy; Attention deficit hyperactivity disorder; Anxiety; Children

Core Tip: For children with attention deficit hyperactivity disorder and comorbid anxiety, a 12-week intervention combining structured social skills education with nondirective sandplay therapy significantly alleviated core behavioral symptoms and anxiety, while enhancing attention function and self-awareness. This comprehensive, non-pharmacological approach yielded high parental satisfaction by integrating external skill-building with internal emotional integration, offering a clinically valuable treatment model that addresses both the psychological and social deficits in this complex pediatric population.

INTRODUCTION

Among school-age children, attention deficit hyperactivity disorder (ADHD) is the most prevalent neurodevelopmental condition. Inattention and hyperactivity-impulsive conduct that is noticeably above the age range are its primary signs[1]. Compared to the general peer group, children with this disease are significantly more likely to experience conduct disorder, oppositional defiant disorder, and antisocial behavior during adolescence. At the same time, the disease will have a lasting negative impact on the child’s academic performance, social adaptability, future family and peer interaction, damage their self-confidence and life satisfaction[2], and also significantly increase the parenting burden[3]. Epidemiological survey shows that the prevalence of ADHD is 3%-9%, which is higher in children with mental disorders, and older children often suffer from anxiety disorders, which further aggravates the severity of core symptoms and the complexity of clinical intervention[4,5]. In the comprehensive intervention of ADHD patients in school-aged and adolescents, behavioral therapy has an irreplaceable position and is often used as a key auxiliary means of drug therapy[6,7]. However, although conventional behavior correction can reduce impulsive behavior, it still faces challenges in promoting children’s emotions and improving their social skills[8]. For children with ADHD comorbid anxiety, simple behavior intervention is difficult to touch the deep emotional distress of children, so it is urgent to explore a comprehensive intervention program that can improve both external behavior and internal emotion.

As a structured intervention, social skills education helps children master interpersonal interaction rules and emotion recognition strategies through systematic processes such as demonstration, exercise and feedback, aiming to establish positive peer relationships and improve social functions[9]. Sandplay therapy constructs a non-verbal and representational expression field for visitors, which promotes the projection and display of internal emotions and conflicts in symbolic form, helps alleviate emotional problems such as anxiety and depression, and improves adaptive behavior in real society[10]. In view of the limitations of a single intervention and the dual problems of external behavior and internal emotion of children with ADHD comorbidity anxiety, this study intends to combine social skills education with sandplay therapy to explore the impact of the combined intervention model on ADHD core symptoms, anxiety, attention function and self-consciousness of children with ADHD comorbidity anxiety, in order to provide a new comprehensive non drug idea for the clinical intervention of this group. The relevant results are reported as follows.

MATERIALS AND METHODS

The study included fifty-two children who were hospitalized to Liaoning Maternal and Child Health Hospital between June 2023 and June 2025 and had been diagnosed with ADHD combined with anxiety disorders. Using a random number table, they were split into two groups at random: (1) An observation group (n = 26); and (2) A control group (n = 26). The two groups’ overall characteristics did not differ statistically significantly, including age, gender, and disease duration (P > 0.05). This study was reviewed and approved by the Ethics Committee of Liaoning Maternal and Child Health Hospital (No. 20260116001). The legal guardians of all children signed written informed consent before joining the group.

Exclusion and inclusion criteria

Inclusion criteria: (1) Meeting the diagnostic criteria for ADHD[11]; (2) Meeting the diagnostic criteria for childhood anxiety[12]; (3) The child has not recently received related drug treatment; (4) The child has basic verbal communication skills; and (5) An informed permission form has been signed by the guardian.

Exclusion criteria: (1) The child has delayed development of the nervous system; (2) The youngster has been diagnosed with a serious mental illness, such as bipolar disorder or schizophrenia; and (3) The child and family members have poor compliance.

Sample size calculation

Sample size calculation formula: The main outcome indicator of this study is the total score of the Screen for Child Anxiety Related Disorders (SCARED) scale for children after the intervention. According to the literature, the SCARED scale score for children with ADHD is obtained. Based on previous studies[13], it is expected that the difference in total score between the two groups after the intervention will be 12, the standard deviation will be 12, the significance level will be 0.05, the power will be 0.9, and the ratio of the number of children in the two groups will be 1:1. The calculated sample size for the two groups is 21 cases. Considering a dropout rate of 10%, it is expected that 24 cases will be included in each group, and the total sample size will be 48 cases. A total of 52 children were included in this study, which meets the sample size requirement.

Methods

Control group: The control group received routine training intervention, focusing on systematic correction of children’s impulsive behavior. Through individual psychotherapy, timely feedback on the consequences of inappropriate behavior was provided to reduce its occurrence. Simultaneously, positive guidance was used to help children establish adaptive behavioral patterns, and positive reinforcement and support were given when they made appropriate choices. The intervention lasted 12 weeks.

Observation group: Social skills education combined with sandplay therapy on the basis of the control group. The implementation process of the social skills education course: The course consists of four parts: (1) Children’s class time; (2) Parents’ class time; (3) Activity time; and (4) Homework. The course is conducted in groups of 3-5 children, led by senior educational psychology experts, for a total of 12 classes, once a week. Children’s class time mainly focuses on learning new social skills. The initial learning focus is on self-awareness and emotional management, such as recognizing different emotions and physical signals, including anxiety, and learning simple self-calming methods such as deep breathing. The subsequent stage systematically learns two-way dialogue skills, making friends, using appropriate humor, dealing with rejection, and how to manage and express anger. In each social skills learning exercise, the instructor will systematically and specifically teach the children detailed rules and steps. Each socialization exercise has clear steps. The children practice through role-playing, including two demonstrations of more effective and less effective methods, which aim to guide the children to observe, compare and find the key points. Then, they practice on the spot in a safe atmosphere to consolidate the correct rules and steps. Parents’ classes focus on teaching parents how to act as social coaches for their children at home in a supportive manner, helping children repeat and practice newly learned skills. Specific content includes: (1) How to understand the behavioral manifestations of ADHD and anxiety comorbidity, learning to use positive and specific prompts, such as “try using the ’four-step conversation initiation method’ we learned in class”; and (2) How to help children complete their homework. For example, trainers will guide parents on how to remind their children to prepare toys that can be shared, rather than games that are only for solo play, before group activities; guide parents on how to plan low-stress playmate dates and provide appropriate assistance during the process. At the same time, attention is paid to parents’ own emotional management to avoid passing on anxiety to their children. The focus of the activity time is to encourage children to try. At the beginning of each class, an emotional thermometer is used for attendance to understand the child’s emotional state in a non-judgmental way. Then, homework is reviewed with an encouraging and exploratory attitude, focusing on the difficulties and gains encountered in the process of trying, emphasizing the value of trying itself, rather than just focusing on whether it is successful. After resolving the problems encountered, new social skills topics are introduced, and rules are explained, role-playing and step-by-step practice are conducted. Homework is based on the specific content taught in the social skills course and is designed with graded practice tasks. Homework should have clear basic goals, such as: “Use polite language with family members at least once this week”, “try to invite a friend”, etc., to ensure that each child can have a successful experience. With the help of parents, children are required to practice new skills with family members and peers in daily life to enhance their ability to use these skills in different environments. Parents should record the child’s attempts and communicate them at the next parent class.

The specific steps of sandplay therapy are as follows: (1) During the initial therapy session, the sandplay environment is introduced to the child in simple and clear language, explaining that sand and all the models on the shelf can be used to create a world in the sandplay according to their own ideas. The child is also informed that each session lasts about 40 minutes to establish basic trust and framework; (2) The child is encouraged to create sandplay works spontaneously and freely according to their own wishes and feelings. No theme restrictions or interventions are set during the process; (3) The therapist stays quietly behind the child and observes the process of the child placing sand objects and the overall creation with focused and accepting eyes; (4) After the work is completed, the therapist accompanies the child to view the completed sandplay world. The therapist mainly uses reflective and descriptive language, such as “you put a very cute puppy here”, to invite the child to share their feelings or thoughts and understand the meaning of the work to them personally, avoiding direct analysis and interpretation; and (5) With the child’s consent, the sandplay work is photographed and recorded. After the child leaves the therapy room, the therapist restores the sandplay to its original state to prepare for the next therapy session. Sandplay therapy was conducted once a week, guided by a professional psychotherapist. The observation period lasted 12 weeks, with a total of 12 sandplay therapy sessions.

The implementation process of this study was standardized and the follow-up data were complete. All 52 enrolled children completed the whole process of intervention and endpoint index evaluation according to the established scheme, and there was no case loss or missing follow-up. Based on this, the data set of this study conforms to the principles of intention analysis and scheme set analysis at the same time, and all research objects are included in the final effectiveness and safety analysis set.

Observation indicators

All scales involved must be filled out by parents based on the child’s specific behavior over the past week, and the assessment must be completed strictly in accordance with the unified testing standards under the guidance of professionals.

Conners Parent Symptom Questionnaire: Children with ADHD had their clinical symptoms and associated issues evaluated using the Conners Parent Symptom Questionnaire (PSQ)[14]. The scale contains 48 items in 6 dimensions, including hyperactivity index, conduct problems, learning problems, hyperactivity, impulsivity and anxiety. Each item was scored using the Likert scale, and the scores of each dimension were added together. The higher the score, the more obvious the problem the child showed in that aspect.

The Swanson Nolan and Pelham-IV rating scales: The ADHD rating scale [Swanson Nolan and Pelham-IV (SNAP-IV)][15] was used to assess the impact of the child’s core symptoms on their quality of life. The scale contains 26 items, divided into three dimensions: (1) Inattention; (2) Hyperactivity and impulsivity; and (3) Oppositional defiantness. The score was negatively correlated with the quality of life, that is, the higher the score, the lower the quality of life of the child.

Social Anxiety Scale for Children and SCARED: Using the corresponding Social Anxiety Scale for Children (SASC)[16] and the SCARED[17]. The SASC scale has 10 items and is scored on a three-level scale from 0 (no problem) to 2 (frequent occurrence), with a total score of 20. The higher the score, the more pronounced the degree of social anxiety. The SCARED scale has 41 items and is also scored on a three-level scale from 0 to 2. A total score ≥ 23 indicates the risk of anxiety disorder.

Piers-Harris Children’s Self-Concept Scale: The Piers-Harris Children’s Self-Concept Scale (PHCSS), developed and revised by Piers and Harris[18], was used to assess children’s level of self-awareness. The scale contains 80 items and is divided into six dimensions: (1) Behavior; (2) Intelligence and school performance; (3) Physical appearance and attributes; (4) Anxiety; (5) Sociability; and (6) Well-being and satisfaction. Higher scores indicate higher levels of self-awareness.

Number cancellation test: Using the number cancellation test[19]. The test material was a 25-row × 25-column grid consisting of randomly arranged numbers from 1 to 10. The subjects were required to locate and mark the designated target number as quickly as possible within 10 minutes. The number of correct, incorrect, and missed numbers were recorded to comprehensively assess the individual’s processing speed, selective attention, and sustained attention level.

Comparison of parent satisfaction: After 12 weeks of intervention, a self-designed questionnaire was used to assess parental satisfaction. This scale primarily evaluated training methods, the communication attitude of professionals, and operational skills, using a 0-10 rating scale. A score of ≥ 8 indicated “very satisfied”, 6-7 indicated “most satisfied”, and < 6 indicated “dissatisfied”.

Statistical analysis

SPSS 21.0 statistical software was utilized for data analysis in this study. The measurement data were expressed as mean ± SD. The t-test was used for comparison between groups before intervention, and analysis of covariance was used for comparison between groups after intervention. For group comparisons, χ² tests were employed, and count data are expressed as n (%). Statistical significance was defined as a P value of less than 0.05.

RESULTS

Comparison of general information between the two groups of children

A total of 52 children with ADHD comorbid anxiety were included in this study and randomly assigned to the observation group (n = 26) and the control group (n = 26). During the 12 weeks intervention, the two groups of children and their guardians cooperated well, and there were no cases who withdrew from the study or lost the follow-up for any reason. Finally, all 52 children completed the evaluation of the established intervention program and all scales, with complete data, and entered the final result analysis. The general information of the two groups of children was comparable (P > 0.05; Table 1).

Table 1 Comparison of general data between the two groups, n (%)/mean ± SD.

Variable	Category	Observation group (n = 26)	Control group (n = 26)	Statistical value	P value
Age/years		9.23 ± 1.51	9.46 ± 1.56	0.544	0.589
Gender	Male	14 (53.85)	13 (50.00)	0.077	0.781
	Female	12 (46.15)	13 (50.00)
Course of disease		2.50 ± 1.21	2.30 ± 0.90	-0.689	0.494

Comparison of PSQ scores before and after intervention in the two groups

After the intervention, the observation group scored lower than the control group in the PSQ for hyperactivity index (0.91 ± 0.16 vs 1.06 ± 0.17; F = 8.920, P = 0.004), anxiety (1.02 ± 0.15 vs 1.26 ± 0.22; F = 20.697, P < 0.001), conduct problems (0.92 ± 0.35 vs 1.17 ± 0.15; F = 11.765, P = 0.001), psychosomatic problems (0.62 ± 0.07 vs 0.68 ± 0.13; F = 4.219, P = 0.045), and hyperactivity/impulsivity (1.08 ± 0.21 vs 1.37 ± 0.28; F = 18.090, P < 0.001; Table 2).

Table 2 Comparison of Parent Symptom Questionnaire scores before and after intervention in the two groups, mean ± SD.

Group	Observation time	Hyperactivity index	Anxiety	Character issues
Observation group	Before intervention	1.24 ± 0.18	1.49 ± 0.34	1.28 ± 0.37
	After intervention	0.91 ± 0.16a	1.02 ± 0.15a	0.92 ± 0.35a
Control group	Before intervention	1.23 ± 0.19	1.42 ± 0.33	1.25 ± 0.27
	After intervention	1.06 ± 0.17	1.26 ± 0.22	1.17 ± 0.15

^aP < 0.05, t ≥ 2.009 or F ≥ 4.029, compared with the control group.

Comparison of SNAP-IV scores before and after intervention in the two groups

After the intervention, the observation group scored lower than the control group in SNAP-IV for inattention (1.48 ± 0.36 vs 1.82 ± 0.45; F = 9.150, P = 0.004), hyperactivity (1.27 ± 0.38 vs 1.49 ± 0.41; F = 4.611, P = 0.0.037), and oppositional defiance (1.36 ± 0.31 vs 1.84 ± 0.43; F = 20.805, P < 0.001; Table 3).

Table 3 Swanson Nolan and Pelham-IV scores before and after intervention in the two groups, mean ± SD.

Group	Lack of concentration		Hyperactivity and impulsivity		Opposition and defiance
	Before intervention	After intervention	Before intervention	After intervention	Before intervention	After intervention
Observation group	2.43 ± 0.42	1.48 ± 0.36	2.24 ± 0.45	1.27 ± 0.38	2.35 ± 0.51	1.36 ± 0.31
Control group	2.42 ± 0.45	1.82 ± 0.45	2.17 ± 0.57	1.49 ± 0.41	2.38 ± 0.45	1.84 ± 0.43
Statistical value	-0.096	9.150	-0.484	4.611	0.261	20.805
P value	0.924	0.004	0.630	0.037	0.795	< 0.001

Comparison of SASC and SCARED scores before and after intervention in the two groups

After the intervention, the SASC (8.50 ± 0.71 vs 11.15 ± 0.97; F = 126.580, P < 0.001) and SCARED scores (14.65 ± 2.28 vs 20.42 ± 3.77; F = 42.129, P < 0.001) of the observation group were lower than those of the control group (Table 4).

Table 4 Comparison of Social Anxiety Scale for Children and Screen for Child Anxiety Related Disorders scores before and after intervention in the two groups, mean ± SD.

Group	Social Anxiety Scale for Children score		Screen for Child Anxiety Related Disorders rating
	Before intervention	After intervention	Before intervention	After intervention
Observation group	14.19 ± 2.89	8.50 ± 0.71	26.31 ± 3.30	14.65 ± 2.28
Control group	14.65 ± 3.10	11.15 ± 0.97	25.38 ± 3.16	20.42 ± 3.77
Statistical value	0.556	126.580	-1.030	42.129
P value	0.581	< 0.001	0.308	< 0.001

Comparison of PHCSS scores before and after intervention in the two groups

After the intervention, the observation group scored higher than the control group in terms of physical appearance and attributes (6.89 ± 1.57 vs 6.07 ± 1.03; F = 5.221, P = 0.027) and anxiety (8.07 ± 1.85 vs 7.12 ± 1.38; F = 4.485, P = 0.039) in the PHCSS score (Table 5).

Table 5 Comparison of Piers-Harris Children’s Self-Concept Scale scores before and after intervention in the two groups, mean ± SD.

Group	Observation time	Behavior	Intelligence and school situation	Physical appearance and attributes	Anxiety
Observation group	Before intervention	8.13 ± 1.37	7.44 ± 0.98	5.69 ± 1.24	6.84 ± 1.63
	After intervention	10.07 ± 1.96	8.12 ± 1.13	6.89 ± 1.57a	8.07 ± 1.85a
Control group	Before intervention	8.24 ± 1.67	7.69 ± 1.26	5.53 ± 0.96	7.04 ± 1.24
	After intervention	9.27 ± 1.57	7.94 ± 0.83	6.07 ± 1.03	7.12 ± 1.38

^aP < 0.05, t ≥ 2.009 or F ≥ 4.029, compared with the control group.

Comparison of digit cancellation test results before and after intervention in the two groups

Following the intervention, the observation group had more accurate entries than the control group (56.31 ± 5.40 vs 50.12 ± 4.89; F = 18.162, P < 0.001), but the observation group had fewer errors (0.50 ± 0.65 vs 0.92 ± 0.27; F = 8.976, P = 0.004) and omissions (9.19 ± 1.60 vs 11.46 ± 2.14; F = 18.493, P < 0.001; Table 6).

Table 6 Comparison of digit cancellation test results before and after intervention in the two groups, mean ± SD.

Group	Number of correct entries		Number of incorrect entries		Number of missed entries
	Before intervention	After intervention	Before intervention	After intervention	Before intervention	After intervention
Observation group	38.46 ± 4.50	56.31 ± 5.40	1.62 ± 0.50	0.50 ± 0.65	18.27 ± 3.52	9.19 ± 1.60
Control group	39.62 ± 5.12	50.12 ± 4.89	1.46 ± 0.51	0.92 ± 0.27	18.19 ± 3.61	11.46 ± 2.14
Statistical value	0.863	18.162	-1.104	8.976	-0.078	18.493
P value	0.392	< 0.001	0.275	0.004	0.938	< 0.001

DISCUSSION

Children’s academic, social, and familial activities are negatively impacted by ADHD, a prevalent neurodevelopmental disease. Studies have shown that a significant proportion of children with ADHD have comorbid anxiety, which not only exacerbates the severity of core symptoms but also makes clinical intervention more complex[20]. Although behavioral therapy and drug intervention have been proven effective, the former has challenges in the generalization and maintenance of skills, while the latter is accompanied by potential adverse reactions and compliance problems. A comprehensive intervention program for comorbid anxiety symptoms still needs to be explored. This study combined structured social skills education with concrete, non-directive sandplay therapy to conduct a combined intervention for children with ADHD and comorbid anxiety. The results showed that compared with the control group that only received routine behavioral correction, the combined intervention group showed more significant improvements in multiple dimensions such as ADHD core symptoms, anxiety, attention function, self-awareness and parental satisfaction. The results of this study support the comprehensive value of the combined intervention model for this complex clinical group (Table 7).

Table 7 Comparison of parental satisfaction between the two groups, n (%).

Group	Very satisfied	Basically satisfied	Dissatisfied
Observation group	17 (65.38)	8 (30.77)	1 (3.85)
control group	8 (30.77)	14 (53.85)	4 (15.38)
χ2 value			6.446
P value			0.037

The results of this study show that the observation group has significantly better improvement than the control group in the scores of factors such as hyperactivity index, anxiety, conduct problems and SNAP-IV scale. This indicates that the intervention model of social skills education combined with sandplay therapy can more effectively alleviate the core behavioral symptoms of ADHD. The reasons for this may be: Social skills education is aimed at the social cognitive defects of ADHD children[21]. According to dodge’s social information processing model, ADHD children have deviations in encoding social cues, explaining situations, and selecting responses[22]. Through decomposition teaching, role play and instant feedback, this study systematically corrected the wrong processing mode of children in these links, so that they have more adaptive behavior options in the face of conflict. However, Hanssen et al[23] showed that simple skill training is often difficult to internalize due to the high anxiety state of children. The intervention of sand table game just makes up for this gap[24]. Neuroimaging studies have shown that the excessive activation of amygdala in ADHD comorbid anxiety children can inhibit the executive function of prefrontal lobe, resulting in the inability to use the learned skills in real situations[25]. By providing nonverbal symbolic expression space, sandplay can release the anxiety of children in a safe treatment relationship and reduce the excessive alertness of amygdala[26]. The physiological calmness of this emotion creates conditions for the prefrontal executive function, so that it can apply the learned social skills to daily life. Therefore, the superiority of combined intervention may be due to its integrated regulation of cognition and emotion.

In terms of improving anxiety, the observation group showed a significantly greater decrease in scores on the SASC and SCARED scales than the control group, and the score on the “anxiety” dimension of the PHCSS scale also showed a more significant increase. This suggests that the combined intervention has a prominent effect on alleviating social anxiety and generalized anxiety in children with ADHD. The mechanism may be as follows: (1) Social skills education can systematically reduce the social anxiety of children through decomposition teaching and step-by-step exposure. According to Bandura’s self-efficacy theory, successful experience is the core way to improve self-efficacy[27]. This study designed graded homework to ensure that every child can have a successful experience. This positive feedback corrected the negative self-evaluation of children, thus reducing the expected anxiety in social situations. This process not only enhances children’s social self-efficacy but also significantly reduces their feelings of helplessness and anxiety in interpersonal interactions[28]; and (2) Sandplay plays a unique role in the emotional container and transformation function. Anxiety is essentially a kind of ineffable, diffuse tension. Sandplay uses symbols and images as a medium to make abstract anxiety concrete. During the creative process, children unconsciously invest their anxiety in the sandplay world and gain control over their chaotic inner world by adjusting the layout of sandplay objects and constructing scenes, thereby achieving deep emotional relief and transformation[29]. In addition, the therapist’s non-judgmental and empathetic attention creates an experience of complete emotional acceptance for the child, which helps repair the damaged sense of self-worth caused by frequent criticism due to behavioral problems and reduces their defensive anxiety.

This study also found that the observation group showed greater improvement in the number of correct, incorrect, and missed strokes on the digit elimination test, and significantly improved scores on the physical appearance and attributes and anxiety dimensions of the PHCSS scale. This indicates that the combined intervention not only improved overt behavior and emotions but also promoted the development of overall self-awareness. The improvement of attention function may be due to the release of cognitive resources by the reduction of anxiety level. According to the theory of limited attention resources, individual attention capacity is limited. As an internal interference, anxiety will occupy a lot of attention resources, resulting in the decline of executive function[30]. In this study, the significant relief of anxiety in the observation group means that the cognition previously occupied by anxiety is released and can be used for continuous attention tasks. This explains why tasks requiring continuous attention, such as digital cancellation, improved significantly after intervention. The improvement of self-awareness reflects the deep effect of intervention. ADHD children are often rejected by their peers because of hyperactivity and clumsiness, forming negative body images. Sand table games provide a specific integration space. Children can re-establish a sense of connection with the body through the operation of both hands in the sand table. By creating an orderly world in a limited space, you gain the experience of controlling the body and environment. This nonverbal embodied cognitive process may repair the damaged self-image better than verbal persuasion. At the same time, the peer acceptance experience gained in social skills training also provides realistic feedback for the formation of positive self-concept.

It is worth noting that the parents in the observation group were more satisfied than those in the control group. This may be due to the fact that the joint intervention model incorporates parents as co-coaches. Through parent courses, parents not only gained knowledge of understanding their children’s behavior, but also mastered specific support strategies, transforming from helpless critics to supporters with methods and confidence. This role change reduced the parents’ parenting pressure and improved the quality of parent-child interaction. The improvement of parent-child relationship further consolidated the intervention effect on the children, forming a virtuous cycle[31].

Nevertheless, there are several limitations to this study. First, the design of this study has unequal intervention intensity. On the basis of routine training, the observation group received an additional 12 weeks of weekly social skills education and sandplay therapy, which means that the children and parents in the observation group received significantly more professional attention, time investment and emotional interaction. Due to the lack of an attention placebo control group, it is difficult to completely exclude that the significant improvement in the observation group may be partly due to Hawthorne effect or attention placebo effect, rather than completely due to the specific efficacy of social skills education and sandplay therapy itself. Secondly, the main limitation of this study is the risk of evaluator bias. The main outcome indicators of this study rely on the subjective reports of parents. As the parents of the observation group deeply participated in the social skills education course and acted as the family social coach, they were fully informed of the intervention grouping of their children. This non blind design may introduce a strong expectation bias. The parents of the observation group tend to report more positive improvement because they know that their children have received additional intervention, which may lead to the overestimation of the intervention effect of the observation group. To partially alleviate this problem, this study introduced the relatively objective number cancellation test as the evaluation index of attention function, but this potential bias may still weaken the objectivity of the core conclusion of this study. Finally, the intervention program combines two complex therapies. Future research can further analyze the causes and explore their respective leading mechanisms and optimal combination models. In the future, a more rigorous control group should be set up to avoid the impact of intervention content and intensity; adopt more rigorous methods to control evaluator bias. Such as building a multi-agent and multi-method comprehensive evaluation system, introducing teacher reports, classroom behavior observation and objective neuropsychological tests. The factorial design was used to set up the separate intervention group of social skills education, the separate intervention group of sandplay, the combined intervention group and the control group respectively, in order to clarify the synergy mechanism and the best combination mode of the two therapies.

CONCLUSION

In conclusion, the intervention model combining social skills education with sandplay therapy may effectively improve the core symptoms of ADHD and comorbid anxiety, enhance attention function and self-awareness, and achieve high acceptance among parents. This model integrates external behavioral skills development with internal psychological experience integration, combines individual intervention with family systemic support, and provides a systematic, non-pharmacological, and potentially comprehensive intervention approach for the clinical management of this complex comorbid group.