Effects of Music Therapy Combined with Habit Reversal Training on Children with Tic Disorders: A Retrospective Study

Abstract

Objective:

This study aimed to investigate the effects of music therapy combined with habit reversal training (HRT) on children with tic disorders.

Methods:

A retrospective study was conducted on the clinical data of 122 children diagnosed with chronic tic disorders admitted to Hebei Children’s Hospital Affiliated to Hebei Medical University from January 2021 to January 2024. According to different treatment methods, patients were separated into the HRT group (n = 55), who received routine HRT, and the music therapy group (n = 67), who received music therapy combined with HRT. The baseline data before treatment and the clinical efficacy after 8 weeks of treatment of the two groups were compared. Before and after the 8-week treatment, the Yale Global Tic Severity Scale (YGTSS) scores, serum neurotransmitter levels, Child Behavior Checklist (CBCL), and Pediatric Quality of Life Inventory (PedsQL) were compared between the two groups.

Results:

After an 8-week treatment, the Global Severity Score and Total Tic Score of YGTSS significantly decreased in both groups, with the music therapy group showing lower scores than the HRT group (P < 0.05). The total effective rate in the music therapy group was higher than that in the HRT group (92.54% vs. 80.00%, P < 0.05). Serum dopamine and serotonin levels significantly decreased after treatment in both groups, with the music therapy group showing lower levels than the HRT group (P < 0.05). Conversely, serum γ-aminobutyric acid levels significantly increased after treatment in both groups, with the music therapy group showing higher levels than the HRT group (P < 0.05). The CBCL and PedsQL scores significantly improved after treatment in both groups, with the music therapy group showing a significant decrease in CBCL scores and a significant increase in PedsQL scores compared with the HRT group (P < 0.05).

Conclusion:

Music therapy combined with HRT significantly enhanced treatment efficacy for children with tic disorders. It reduced tic severity, improved behavioral outcomes, and modulated neurotransmitter levels. The study demonstrated the potential clinical value of music therapy as a nonpharmacological treatment for tic disorders.

KEY MESSAGES

• (1)Music therapy combined with habit reversal training (HRT) in children with tic disorders significantly improved their behavioral outcomes and quality of life.
• (2)Music therapy combined with HRT effectively modulated serum neurotransmitter levels, with a significant reduction in dopamine and serotonin levels and a significant increase in γ-aminobutyric acid levels.
• (3)Music therapy combined with HRT significantly reduced tic severity in children with tic disorders.

INTRODUCTION

Tic disorders, including transient or chronic tic disorder and Tourette syndrome, are neurodevelopmental disorders characterized by sudden, repetitive, nonrhythmic motor and vocal actions.[1,2] These conditions generally onset between 5 and 10 years old, and they affect approximately 0.77%–2.99% of children.[3] The prevalence of tic disorders is higher in boys than in girls, with a male-to-female ratio varying from 2:1 to 10:1.[4] Although the exact pathophysiology of tic disorders remains unclear, research suggests that dysregulation in the cortico-striatal-thalamo-cortical (CSTC) circuits,[5] along with imbalances in neurotransmitters such as dopamine (DA),[6] serotonin (5-HT)[7] and γ-aminobutyric acid (GABA)[8], may play critical roles in their development. In addition, environmental factors, including stress and sensory stimuli, have been implicated as potential risk factors to trigger or worsen the condition.[9,10,11]

The conventional treatment for tic disorders includes pharmacological treatment and nonpharmacological treatment. Pharmacological treatments, including DA antagonists and alpha-2 adrenergic agonists, have been applied to reduce tic symptoms, but they are often associated with side effects, such as weight gain, extrapyramidal symptoms, and metabolic disorders.[12] In recent years, nonpharmacological treatments for tic disorders have gained attention because of their potential efficacy and reduced risk of adverse effects compared with medication.[13] Habit reversal training (HRT) has demonstrated significant benefits in reducing tic frequency, addressing emotional and social challenges and improving quality of life.[14,15] However, the efficacy of HRT can be influenced by patient age, compliance, and family support.[16]

Music therapy is a noninvasive, patient-friendly therapy with minimum side effects. It shows positive influences on individuals’ emotional, cognitive, behavioral, and physiological states through the various characteristics of music, such as melody, rhythm, harmony, and the process of engaging in musical activities.[17] Music therapy has been wildly applied in autism spectrum disorder (ASD), attention deficit-hyperactivity disorder (ADHD), or obsessive-compulsive disorder (OCD).[18,19,20] Recent studies showed that music therapy can ease anxiety and depression levels by decreasing cortisol levels and regulating steroid hormones.[21] However, the application and effects of music therapy in the treatment of tic disorders remain underexplored. There is a notable gap in research regarding how music therapy may modulate symptoms and underlying mechanisms in children with tic disorders, warranting further investigation.

This study aimed to investigate the combined effects of music therapy and HRT in children with chronic tic disorders.

MATERIALS AND METHODS

Study Subjects

This study retrospectively analyzed the clinical data of children diagnosed with chronic tic disorders in Hebei Children’s Hospital Affiliated to Hebei Medical University. The children were enrolled from January 2021 to January 2024, with a total of 122 cases included. All guardians and pediatric patients exceeding 8 years old provided informed consent for participation in the study. Medical records were reviewed by two independent researchers to confirm the accuracy of the data entry and to ensure data quality and minimize bias, and discrepancies were resolved through discussion. All clinical assessments were conducted using validated and reliable tools. This study was approved by the Ethics Committee of Hebei Children’s Hospital Affiliated to Hebei Medical University (Approval Number: HBCH-2024-08125).

Sample Size Calculation

The required sample size was calculated based on the primary outcome measure, the Yale Global Tic Severity Scale (YGTSS) score, which is widely recognized as a reliable and valid tool for assessing tic severity. This calculation was performed using a two-sided independent samples t-test with the statistical software G*Power 3.1 (Heinrich-Heine-Universität Düsseldorf, Germany). We used a standardized effect size of 1.2 derived from a previous study,[22] a significance level (α) of 0.05 and a statistical power (1 − β) of 0.80. The formula is n = [(Z_α/2 + Z_β)² × 2 × σ²]/δ², in which σ represents estimated variance, and δ represents effect size. The minimum sample size per group was estimated to be 22 participants. The sample size of this study was 60 cases, which reached the minimum sample size required for adequate statistical power, ensuring the reliability of our study results.

Inclusion and Exclusion Criteria

The inclusion criteria were as follows: (1) 5–14 years old; (2) meeting the diagnosis of chronic tic disorders, defined by abrupt, repetitive, nonrhythmic, and stereotypical motor actions or vocal sounds;[23] (3) symptoms lasted at least 1 year, with tic-free interval less than 3 months; (4) families equipped with devices to play music; and (5) children and guardians with good adherence. The exclusion criteria were as follows: (1) tics caused by medications or organic diseases; (2) co-existing hearing impairments; (3) severe psychiatric comorbidities; and (4) currently receiving pharmacological treatment.

Grouping and Treatment Methods

Patients were divided into the music therapy group (n = 55) and the HRT group based on their treatment methods (n = 67).

The HRT group conducted routine HRT as the primary treatment. The treatment consisted of the following steps: (1) Awareness training. Guide the patient to identify the particular warning signs or sensations that come before their tics; this included identifying the situations, sensations, and movements associated with the tic behaviors. (2) Competing response. After awareness is established, the patient engages in a competing response, which consists of a voluntary action that physically conflicts with the tics. For example, if the tics involve head jerking, the competing response might be gently tensing the neck muscles while holding the head still. The competing response is maintained for several minutes or until the urge subsides. Motivation enhancement is introduced through education and reinforcement, including positive feedback from therapists or family members for the successful implementation of the competing response. (3) Generalization training. Encourage the children to apply the competing response in various real-life settings where tics commonly occur. Throughout the treatment, regular practice and follow-up are conducted to monitor progress, address challenges, and reinforce behavioral changes. The treatment lasted for 8 weeks.

The music therapy group received additional music therapy. (1) The music chosen for therapy was selected based on the preferences of the patients and suitability for their age. Before the therapy sessions, a brief assessment of individual preferences was conducted to identify music genres and styles that the children were most comfortable with. A music media library was established, containing a total of 30 tracks, with a time duration of 3.24 ± 0.45 min per track. All tracks were instrumental music to avoid the distraction of lyrics. The music included natural background music, Chinese classical and folk music, famous international pieces, and relaxation music. Prior to the therapy, the music library was played for the children and their guardians. The children and guardians discussed and agreed on 10–12 preferred tracks, which were then selected as the music for subsequent therapy sessions. (2) The first therapy session took place in a dedicated treatment room in the hospital, where a professional therapist guided the children on breathing exercises and muscle relaxation, with the children’s guardians accompanying them. After the first session, the therapists provided training for the guardians, covering the required environment, music selection, and treatment frequency. The guardian’s understanding of the protocol was assessed through a brief evaluation. Once the guardian passed the assessment, subsequent therapy sessions were conducted at home. The guardians were responsible for supervising the patients’ participation in music therapy and for completing a treatment log provided by the hospital. The children’s bedrooms were prepared each night before sleep, with dim lighting set up to maintain a calm environment. The selected music was played at a volume of 40–45 dB through high-quality speakers. Each session lasted 30 min, and the total treatment duration lasted for 8 weeks.

Clinical Assessment

Baseline clinical data were extracted from medical records, including sex, age, disease duration, YGTSS scores, complications, and comorbidities. The clinical manifestations of tic disorders in children were assessed before and 8 weeks after the treatment. The YGTSS scores and the clinical efficacy were defined as the primary outcome of this study, whereas neurotransmitter levels, Child Behavior Checklist (CBCL) scores, and Pediatric Quality of Life Inventory (PedsQL) scores were defined as secondary outcomes.

(1) YGTSS: The scale assesses motor tics and phonic tics across five dimensions: number, frequency, intensity, complexity, and interference. Each dimension was scored on a scale from 0 to 5, resulting in a maximum score of 25 for motor tics and 25 for phonic tics. The sum of the scores for motor tics and phonic tics was labeled as the YGTSS–Total Tic Score (TSS), with a range of 0–50. In addition, the functional impairment of tics on daily activities, including academic performance, social interactions, and family life, was scored on a scale from 0 to 50. The YGTSS–Global Severity Score (GSS) is the sum of the symptom severity score and the functional impairment score, yielding a final range of 0–100. Cronbach’s α of YGTSS is 0.79–0.87.[24,25]

(2) Clinical efficacy: The clinical efficacy was categorized into four levels: cured, markedly effective, effective, and ineffective. Cured was defined as the near-complete resolution of tics, with a YGTSS score improvement rate of ≥95% and no recurrence for more than 1 month. Markedly effective referred to a significant improvement in tic symptoms, with the YGTSS score improvement rate of ≥70% but <95%. Effective indicated a moderate improvement in tic symptoms, with the YGTSS score improvement rate of ≥30% but <70%. Ineffective was characterized by either no change or a deterioration in tic symptoms, with the YGTSS score improvement rate of <30%. The total effective rate was calculated as the sum of “cured,” “markedly effective,” and “effective” divided by the total number of participants.

(3) Serum neurotransmitter levels: In the early morning, a fasting venous blood sample of 3 mL was obtained from each patient. The blood was set aside at room temperature for 30 min and then subjected to centrifugation at 2000 rpm for 10 min. The supernatant was extracted and stored at −80°C. Serum DA and 5-HT were measured using reverse-phase high-performance liquid chromatography, whereas GABA was determined using enzyme-linked immunosorbent assay.

(4) CBCL and PedsQL: CBCL evaluates behavioral problems in children, with scores ranging from 0 to 2 (0 = absent; 1 = occurs sometimes; and 2 = occurs often).[26] It consists of 113 items divided into eight syndrome subscales and two broad-band scales. The total score of ≥44 for boys and ≥42 for girls represents the presence of behavioral problems. The Cronbach’s α of CBCL is 0.90.

Quality of life was assessed using PedsQL, focusing on physical, emotional, social, and school areas.[27,28] A 5-point Likert scale was used to score each item. Scores were linearly transformed to a 0–100 scale. Higher scores indicate a better quality of life. Domain scores were calculated as the average of item scores within each domain, and the overall PedsQL score was computed as the mean of all items across domains. The Cronbach’s α of PedsQL was 0.88–0.92.

Statistical Analysis

Data were analyzed using IBM SPSS Statistics for Windows 24.0 (IBM Corp., Armonk, NY, USA). Tables in the study were created using Microsoft Excel 2021. The distribution of continuous variables was tested using the Shapiro–Wilk test. Categorical variables were expressed as n (%), and comparisons were conducted using the Chi-square test. Continuous variables following a normal distribution were presented as mean ± standard deviation (x̄±s), and comparisons between two groups were performed using independent samples t-tests. For comparisons of continuous variables before and after treatment within the same group, paired t-tests were used. P < 0.05 was considered statistically significant.

RESULTS

Baseline Characteristics

Table 1 shows that age, sex, duration of tic disorders, complications, and comorbidities showed no statistical significance (P > 0.05), ensuring comparability for the subsequent analysis of treatment effects.

Table 1.

Baseline characteristics of the two groups

Item	HRT group (n = 55)	Music therapy group (n = 67)	t/χ 2	P
Age (year, x̄±s)	6.33 ± 1.27	6.45 ± 1.21	0.533	0.595
Sex (n,%)
Male	38 (69.09)	43 (64.18)	0.327	0.568
Female	17 (30.91)	24 (35.82)
Duration of disease (m, x̄±s)	15.52 ± 2.37	15.24 ± 2.41	0.643	0.521
Complication and comorbidity (n,%)
Sleeping disorder	18 (32.73)	20 (29.85)	0.117	0.733
ADHD	23 (41.18)	23 (34.33)	0.721	0.396
Anxiety/Depression	3 (5.45)	2 (2.99)	0.469	0.494
OCD	11 (20.00)	14 (20.90)	0.015	0.903

Notes: ADHD refers to attention deficit hyperactivity disorder, and OCD stands for obsessive-compulsive disorder.

Comparison of YGTSS Scores

The music therapy group showed a greater reduction in YGTSS-GSS and YGTSS-TSS scores compared with the HRT group (P < 0.05), indicating a significant improvement in tic symptoms, as presented in Table 2.

Table 2.

YGTSS scores before and after treatment

Group	YGTSS-GSS		YGTSS-TSS
	Before treatment	After treatment	Before treatment	After treatment
HRT group (n = 55)	46.25 ± 4.86	29.52 ± 5.46#	34.94 ± 2.31	22.45 ± 3.17#
Music therapy group (n = 67)	47.13 ± 5.30	21.49 ± 5.05#	34.57 ± 3.01	18.63 ± 2.81#
t	0.947	8.425	0.748	7.051
P	0.346	<0.001	0.456	<0.001

Notes: YGTSS, the Yale Global Tic Severity Scale; GSS, Global Severity Score; TSS, Total Tic Score; ^# Compared with before treatment within group, P < 0.05.

Comparison of Clinical Efficacy

According to Table 3, the music therapy group had a higher total effective rate compared with the HRT group (92.54% vs. 80.00%, P = 0.041).

Table 3.

Clinical efficacy of the two groups

Efficacy level	HRT group (n = 55)	Music therapy group (n = 67)
Cured	10 (18.18)	24 (35.82)
Effective	13 (23.64)	23 (34.33)
Markedly effective	21 (38.18)	15 (22.39)
Ineffective	11 (20.00)	5 (7.46)
Total effective rate	44 (80.00)	62 (92.54)
χ 2	4.167
P	0.041

Comparison of Serum Neurotransmitter Levels

According to Table 4, a significant reduction in serum DA and 5-HT levels was observed after 8-week treatment in both groups. The music therapy group had significantly lower levels than the HRT group (P < 0.05). After treatment, significant increases in serum GABA levels were observed in both groups. The music therapy group had higher levels than the HRT group (P < 0.05), suggesting a pronounced effect on neurotransmitter modulation.

Table 4.

Serum neurotransmitter levels before and after treatment

Group	DA (pg/mL)		5-HT (ng/mL)		GABA (µmol/L)
	Before treatment	After treatment	Before treatment	After treatment	Before treatment	After treatment
HRT group (n = 55)	6.63 ± 1.68	4.62 ± 0.79#	75.47 ± 4.83	60.67 ± 4.83#	1.62 ± 0.43	2.15 ± 0.42#
Music therapy group (n = 67)	6.72 ± 1.74	4.19 ± 0.56#	75.2 5 ± 5.04	56.97 ± 5.36#	1.59 ± 0.47	2.46 ± 0.33#
t	0.289	3.510	0.244	3.965	0.364	4.565
P	0.773	<0.001	0.807	0.001	0.716	<0.001

Notes: DA refers to dopamine; 5-HT to serotonin; GABA to γ-aminobutyric acid. ^# Indicates a significant difference compared with before treatment within the group, with P < 0.05.

Comparison of CBCL and PedsQL Scores

Table 5 shows a notable increase in PedsQL scores after 8-week treatment for both groups, with the music therapy group achieving higher scores than the HRT group (P < 0.05). At the same time, both groups showed significantly reduced CBCL scores after treatment, whereas the music therapy group had lower scores than the HRT group (P < 0.05). These results indicated a favorable effect in terms of behavioral outcome and quality of life.

Table 5.

CBCL and PedsQL scores before and after treatment

Group	CBCL		PedsQL
	Before treatment	After treatment	Before treatment	After treatment
HRT group (n = 55)	56.02 ± 6.17	35.74 ± 5.62#	74.84 ± 5.43	81.62 ± 5.02#
Music therapy group (n = 67)	56.27 ± 6.03	31.15 ± 4.26#	73.86 ± 5.93	85.41 ± 5.33#
t	0.225	5.129	0.943	4.011
P	0.822a	<0.001	0.348a	<0.001

Notes: CBCL refers to the Child Behavior Checklist, and PedsQL stands for the Pediatric Quality of Life Inventory. ^# Indicates a significant difference compared with before treatment within the group, with P < 0.05.

DISCUSSION

Many children have experienced brief tics, which generally relieve with age. However, in cases of chronic tic disorders or Tourette syndrome, symptoms persist for over a year and are often accompanied with multiple motor and vocal tics.[29] The symptoms can cause social difficulties, personality and emotional challenges, and learning problems, and they are often found alongside psychiatric conditions like ADHD, OCD, anxiety, and depression.[1] The conventional treatments for tic disorders should encompass cognitive-behavioral therapy, pharmacological treatment, and family education to mitigate the impact of tic behaviors, prevent comorbidities, and enhance the quality of life.[30] However, conventional pharmacological treatments for tic disorders often result in undesirable side effects such as obesity, extrapyramidal symptoms, and metabolic disturbance, which can affect long-term patient adherence and overall well-being.[12]

There has been limited previous research on the application of music therapy in tic disorders. Bodeck et al.[31] demonstrated that musical activity significantly reduces the frequency of tics in Tourette syndrome. Previous studies on other pediatric conditions, such as ASD, varied in their treatment durations, ranging from 30 min three times a week to 45 min once a week, without specifying the time of day.[32,33] We chose to play music before bedtime to promote relaxation and improve sleep quality, which may help reduce stress and tic severity in this study. The results of the present study showed that YGTSS scores after treatment in the music therapy group were significantly lower than those in the HRT group, with a higher total effective rate in the music therapy group than in the HRT group. These results suggested that music therapy combined with HRT could reduce clinical symptoms and frequency of tics in children. In a study by Wang et al.[15] HRT assisted patients in recognizing the occurrence of each tic or its premonitory urges, followed by competing response training to interrupt or suppress the tics. Additionally, music therapy promoted neuroplasticity by stimulating the formation of new neural connections and enhancing reward sensations while also lowering stress levels and reducing cortisol secretion, thereby alleviating inflammatory responses in the body.[34] Furthermore, studies have reported that music therapy can mitigate symptoms of depression and anxiety, as well as improve sleep quality.[35,36] Consequently, the combined treatment approach demonstrates superior efficacy in treating tic disorders.

DA and 5-HT have excitatory effects on the nervous system, and GABA inhibits excessive central nervous system excitation.[37] GABA is a primary inhibitory neurotransmitter in the central nervous system, and its deficiency may lead to excessive neural excitation, thereby triggering tic symptoms.[38] A previous study indicated that the concentration of GABA is reduced in the brains of children with tic disorders, with the degree of reduction correlating with the severity of tic symptoms.[38] Currently, GABA receptor agonists have been applied for children with tic disorders.[8] A study on healthy elderly individuals found that musical rhythm production is associated with frontal GABA levels, suggesting that musical activity may influence neural function by modulating GABA levels.[39] Other studies have shown that DA levels are abnormally elevated in the basal ganglia of patients with tic disorders, triggering tic behaviors by activating DA receptors in the striatum and subsequently leading to hyperexcitability of the CSTC circuit.[40] A study has shown increased DA transporter binding in the striatum of patients with tic disorders, suggesting that DA regulation may play a significant role in the symptoms of tic disorders.[7] Music can modulate the brain’s reward pathways, particularly the ventral tegmental area and nucleus accumbens, which are closely associated with the regulation of DA.[41] Excessive DA activity is considered one of the core pathological mechanisms of tic disorders, and changes in 5-HT levels may influence tic behaviors by regulating DA release.[29] Our study showed that GABA levels increased while DA and 5-HT levels decreased in the music therapy group, with significant differences compared with the HRT group. Thus, music therapy could modulate the levels of key neurotransmitters, improving the balance between excitatory and inhibitory signals in the brain, which may contribute to the alleviation of tic symptoms. Through neurotransmitter regulation, music therapy not only alleviated tic symptoms but also positively impacted patient behavior and quality of life.[36,42] In this study, the improvement of CBCL and YGTSS scores in the music therapy group was significantly better than that in the HRT group, indicating that music therapy could improve patient behavior, reduce emotional distress such as anxiety and depression, and enhance social interactions and school performance. The improvement in tic syndromes and emotions subsequently ameliorated the quality of life, resulting in the improvement of PedsQL scores in the music therapy group.However, our study had several limitations. The small sample size and retrospective design may limit the generalizability of the results and introduce biases, impacting the external validity. The 8-week treatment period was relatively short, which restricted our ability to assess the long-term effects of music therapy. Future research should include a large, demographically diverse sample, as well as design a prospective study to control for potential confounders and enhance the robustness of the findings. Another limitation is that the music therapy was only conducted before bedtime. Future research should consider playing music at different times of the day to assess the best time for music therapy. Additionally, the study did not conduct sensitivity analyses to evaluate the robustness of the results, particularly with respect to factors like adherence or baseline severity. In future studies, these analyses will be critical. Furthermore, exploring genetic and neuroimaging approaches could provide a deep understanding of how music therapy influences tic disorders at the neural and genetic levels, revealing potential mechanisms of action.

CONCLUSION

In summary, our study indicated that music therapy is an effective therapy for tic disorders in children. The combination of music therapy and HRT could significantly improve treatment efficacy, reduce tic severity, improve behavioral outcomes, and modulate neurotransmitter levels.

Availability of Data and Materials

The datasets generated and analyzed in the current study are available from the corresponding author upon reasonable request.

Author Contributions

Yali Liu: Responsible for research design and implementation, data collection and analysis, and writing the first draft. Haixia Chang: Participated in research design, assisted in data analysis, and made preliminary revisions to the manuscript. Xiulin Li: Responsible for experimental technical guidance and quality control during data collection. Mingjing Zhang: Participated in data collation and analysis and proofread and optimized the content of the paper. Xia Wang (corresponding author): Responsible for the overall research design and supervision, provided technical and theoretical support, and gave final review and approval of the paper.

Ethics Approval and Consent to Participate

This study was approved by the Ethics Committee of Hebei Children’s Hospital Affiliated to Hebei Medical University (Approval Number: HBCH-2024-08125). All guardians and pediatric patients exceeding 8 years old gave informed consent to participate in the study.

Conflicts of Interest

The authors declare no conflicts of interest.

Funding Statement

This study was funded by the Medical Science Research Project of Hebei (20220777).