Neurocognitive and Behavioral Profiles of Children with Tic Disorders/Tourette Syndrome
Article information
Abstract
Purpose
Children with tic disorders/Tourette syndrome (TD/TS) frequently present with co-occurring neuropsychiatric conditions, such as obsessive-compulsive disorder and a range of behavioral issues. However, these accompanying problems may be overlooked during diagnosis. This study aimed to investigate the neurocognitive and behavioral characteristics of children with TD/TS who visited a pediatric clinic.
Methods
We retrospectively reviewed medical records of children diagnosed with TD/TS at a secondary referral center in Korea. A subset of these data was statistically compared with those from healthy controls. To minimize confounding factors, only children with cognitive development within the normal range were included.
Results
Data from 36 children with TD/TS (27 males, nine females; ages 6 to 14 years, mean 9.5±2.1) were analyzed. The mean Full Scale Intelligence Quotient (FSIQ) on the Korean–Wechsler Intelligence Scales for Children (K-WISC) was 98.8±11.7 (n=24). Compared with healthy controls (n=38), the TD/TS group (n=13) scored significantly lower on the Perceptual Reasoning Index, despite no group difference in overall FSIQ (K-WISC-IV). On the Korean Child Behavior Checklist, the TD/TS group showed significantly higher rates of clinical-range scores in multiple domains, including anxiety, somatic complaints, attention problems, and obsessive-compulsive behaviors (P<0.05). The mean Korean-attention-deficit/hyperactivity disorder Rating Scale-IV (K-ARS-IV) score was 11.3±7.7, with 17.1% of participants exceeding the clinical threshold.
Conclusion
Children with TD/TS and normal cognitive development demonstrate specific neurocognitive weaknesses and elevated behavioral/emotional problems. Early behavioral and cognitive assessments should be incorporated into the initial evaluation.
Introduction
Tic disorder (TD) is a childhood-onset neurodevelopmental condition defined by involuntary, sudden, uncontrollable, and repetitive muscle movements or vocalizations. Tourette syndrome (TS) is diagnosed when both motor and vocal tics are present. TD/TS are movement disorders of neurobiological origin, often associated with or exacerbated by psychobehavioral problems [1]. The estimated lifetime prevalence of TD is 0.1% to 1%, with onset typically between ages 5 and 6 years [2,3]. Symptoms usually first appear in the head and neck and may later involve muscles of the torso, arms, and legs. TD/TS occurs more frequently in boys than in girls, and motor tics generally precede vocal tics [4,5]. Common simple motor tics include eye blinking, neck jerking, shoulder shrugging, and facial grimacing, while simple vocal tics often consist of throat clearing, barking, sniffing, and hissing [5,6]. Symptoms usually peak between ages 10 and 12 years. Approximately one-half to two-thirds of cases improve significantly by late adolescence or early adulthood, though in some individuals, TD/TS may persist or even worsen in adulthood [4,7].
TD/TS shares clinical and genetic features with obsessive-compulsive disorder (OCD). Neurophysiological and neuroimaging studies have identified abnormalities in networks involving the frontal cortex, supplementary motor area, premotor areas, striatum, globus pallidus, and thalamus [8-10]. Pathological changes in the cortico-striatal-thalamo-cortical (CSTC) circuit are implicated, with dopamine dysfunction considered a primary factor [11,12]. Dysregulation of CSTC circuits, which govern motor, emotional, and adaptive functions, along with abnormalities in dopamine and serotonin pathways, is believed to underlie both TD/TS and its comorbidities [13-15].
Treatment of tics typically begins with education and supportive measures. Behavioral interventions such as habit reversal training and the comprehensive behavioral Interventions for Tics are used as non-pharmacological approaches. Pharmacological treatment is usually reserved for more severe cases, with dopamine D2 receptor antagonists being the most effective for tic suppression. Typical neuroleptics such as haloperidol and pimozide have proven effective, while atypical antipsychotics like aripiprazole are increasingly favored for their more favorable side effect profiles [15-18].
Children with TD/TS have a higher prevalence of comorbid neuropsychiatric and behavioral disorders than the general population, including attention-deficit/hyperactivity disorder (ADHD), OCD, emotional dysregulation, and disinhibited speech or behavior [6,8]. These vulnerabilities may increase susceptibility to bullying, which in turn can lead to school refusal, social withdrawal, and long-term developmental impacts.
Severe tics can impair both social and academic functioning, and the presence of comorbid conditions may further complicate treatment and prognosis. Thus, it is essential to evaluate coexisting neuropsychiatric issues at the time of initial diagnosis and throughout follow-up [17,18]. Early identification may reduce negative educational and social outcomes and improve long-term prognosis.
Although TD/TS is a clinically significant neurodevelopmental disorder, research on the comprehensive neurocognitive and behavioral profiles of affected children remains limited. While several studies report that children with TD generally have normal intelligence, they often show lower Processing Speed Index (PSI) scores than healthy controls (HC) [19-21] and display a range of behavioral problems on standardized assessments [22]. In addition, studies using the Korean Child Behavior Checklist (K-CBCL) have shown significantly higher mean T-scores for attention problems, anxiety/depression, withdrawal, and emotional lability in children with TD/TS compared with controls [20].
Despite these findings, relatively few studies have simultaneously examined both cognitive and behavioral characteristics in children with TD. To better support affected children, especially those experiencing subtle difficulties in social adaptation, a more comprehensive understanding of their neurobehavioral profiles is needed [23].
The aim of this study was to evaluate the neurocognitive and behavioral characteristics of children with TD/TS and to identify specific associated traits. We hypothesized that children with TD/TS would differ significantly from HCs in both cognitive functioning and behavioral problems. While current management often includes reassurance, behavioral therapy, or medication, delayed recognition of coexisting psychological and behavioral issues may result in untreated problems persisting into late adolescence.
Materials and Methods
1. Subjects
We retrospectively reviewed the medical records of children who visited the Pediatric Neurology Clinic at Hanyang University Guri Hospital between March 1, 2014, and July 31, 2023, and were diagnosed with TD/TS. The inclusion criteria were as follows: children aged 6 to 14 years; diagnosis of TD/TS based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR); and availability of cognitive or behavioral assessment results obtained during the diagnostic process. Exclusion criteria were: a Full Scale Intelligence Quotient (FSIQ) score below 70 on standardized intelligence quotient (IQ) tests, or clinical suspicion of significantly low cognitive ability if IQ testing was not conducted; and a diagnosis of significant brain disorders, including intractable epilepsy, neurovascular disease, neurological infections, head trauma, neurometabolic conditions, movement disorders other than TD/TS, or autism spectrum disorder. Based on these criteria, 36 children with TD/TS were included (22 with TD and 14 with TS). For comparison, data from 38 age- and sex-matched typically developing children (HC) were used. To minimize confounding, only children with normal-range cognitive development were included. Control data were obtained from a previous study (NRF-2015R1D1A1A02062396) conducted by the authors, which did not contain personally identifiable information. The Institutional Review Board of Hanyang University Guri Hospital approved all research protocols (IRB No. 2024-01-004-001). Written informed consent by the patients was waived due to a retrospective nature of our study.
2. Data collection
1) Clinical data
Demographic and baseline clinical characteristics were obtained through retrospective chart review. Extracted information included age, sex, medical history, symptom characteristics, diagnosis, treatment for tics, and comorbid conditions.
2) Neurocognitive and behavioral assessments
Neurocognitive and behavioral assessments were administered, most commonly at the time of initial diagnosis. Testing was performed either as a comprehensive neurocognitive function test (NCFT) or as an abbreviated behavioral screening test (BST), depending on clinical circumstances.
For NCFTs, the following instruments were analyzed: the Korean–Wechsler Intelligence Scales for Children (K-WISC; editions III, IV, or V depending on year), the K-CBCL for Ages 6–18 (K-CBCL 6–18), the Rey–Kim Memory Test for Children, the Children’s Color Trails Test (CCTT), the STROOP Color and Word Test (STROOP), the Korean Children’s Depression Inventory (K-CDI), the Social Maturity Scale (SMS), and the Korean ADHD Rating Scale-IV (K-ARS-IV). For BSTs, which included selected NCFT subtests, the K-CBCL 6–18, K-CDI, SMS, and K-ARS-IV were used. Among the participants, 24 underwent NCFTs and 12 underwent BSTs.
3) Intellectual function
The K-WISC comprises multiple subtests and composite scores, which vary by edition, each yielding an FSIQ. K-WISC-III (2001) provides verbal IQ (VIQ), performance IQ (PIQ), and FSIQ based on 10 core subtests. K-WISC-IV (2008) reorganized subtests into four indices: Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI), and PSI. K-WISC-V (2021) further refined domains into five indices: VCI, Visual-Spatial Index (VSI), WMI, PSI, and Fluid Reasoning Index (FRI). The PRI from K-WISC-IV was separated into VSI and FRI in the K-WISC-V [24]. Despite differences in structure, many subtests assess conceptually similar domains. For group comparisons between TD/TS and HC, only results from the same edition (K-WISC-IV) were analyzed.
4) Behavioral problems and social scales
The K-CBCL 6–18 is a parent-reported questionnaire with 120 items assessing emotional and behavioral problems in children and adolescents. It consists of eight subscales—anxious/depressed, withdrawn/depressed, somatic complaints, social problems, thought problems, attention problems, delinquent behavior, and aggressive behavior, which are further grouped into internalizing and externalizing dimensions [25].
The SMS evaluates social competence and adaptive functioning. It yields a social age (SA), representing age-equivalent social development, and a social quotient (SQ), calculated as SA divided by chronological age×100. The K-CDI is a self-report tool for evaluating depressive symptoms in children and adolescents.
5) Attention and executive function
Executive function was assessed using the CCTT and STROOP tests. The CCTT evaluates attention, divided attention, visual scanning, sequencing, psychomotor speed, and cognitive flexibility [26]. The STROOP measures cognitive inhibition and interference susceptibility, capturing the classic ‘stroop effect’ [27]. The Rey–Kim Memory Test for Children provides a memory quotient (MQ), conceptually comparable to IQ. Additionally, the K-ARS-IV, completed by parents and teachers, served as a primary ADHD screening tool. It contains 21 items consistent with DSM-IV and DSM-5 criteria and provides total, inattention, and hyperactivity/impulsivity scores, along with cutoff thresholds based on informant ratings [28]. Children exceeding cutoff scores were classified as high risk for ADHD.
This study analyzed K-WISC (III, IV, V) IQ and subscales, K-CBCL 6–18 T-scores, CCTT and STROOP scores, MQ from the Rey–Kim Memory Test, SA and SQ from the SMS, and K-CDI scores in the TD/TS group. Comparisons between TD/TS and HC groups were conducted using K-WISC-IV, K-CBCL 6–18, Rey–Kim, CCTT, and STROOP results.
3. Statistical analysis
Descriptive statistics, including mean±standard deviation and frequency (percentage), were used to summarize demographic and clinical characteristics. Between-group differences in age, WISC-IV subscales, K-CBCL 6–18 T-scores, Rey–Kim, CCTT, STROOP, and K-ARS scores were analyzed using the independent t-test. The Fisher exact test was applied to compare the proportion of participants classified as the ‘problem group’ (borderline or clinical range) on the K-CBCL 6–18. Analyses were performed using IBM SPSS version 26.0 (IBM Corp., Armonk, NY, USA) or R version 4.1.2 (R Foundation for Statistical Computing, Vienna, Austria). Statistical significance was set at P<0.05.
Results
1. Demographics and clinical characteristics
The demographic and clinical characteristics of the TD/TS and HC groups are summarized in Table 1. The mean age of the TD/TS group was 9.5±2.1 years (range, 6 to 14), and the group included 27 males (75.0%). The mean age of symptom onset was 6.8±1.9 years, with an average disease duration of 2.7±2.1 years. On average, patients exhibited 2.6±1.9 motor tics and 0.6±0.9 vocal tics, for a total of 3.1±2.1 tic symptoms. The HC group had a mean age of 9.5±1.4 years (range, 7 to 13), with 27 males (71.1%). No statistically significant differences were observed in age or sex distribution between the TD/TS and HC groups (Table 1).
Demographics and clinical characteristics in the TD/TS and HC groups
2. Neurocognitive function tests and behavioral screening tests
1) The Wechsler Intelligence Scale for Children
Of the 36 participants in the TD/TS group, 24 underwent NCFT and 12 underwent BST. The K-WISC edition varied by testing year: five were assessed with K-WISC-III, 13 with K-WISC-IV, and six with K-WISC-V. All 38 participants in the HC group were evaluated with K-WISC-IV (Table 2).
Results of neurocognitive function tests and behavioral screening tests in the TD/TS and HC groups
The mean FSIQ score in the TD/TS group was 98.8±11.7. Subscale means were as follows: VCI, 102.1±12.5; Perceptual Organization Index (POI)/PRI/FRI/VSI, 95.9±12.6; Freedom from Distractibility Index/WMI, 100.0±14.8; and PSI, 96.8±13.0. In the HC group, the mean FSIQ was 105.2±9.7, with subscale means of: VCI, 103.0±10.6; PRI, 106.3±10.4; WMI, 102.8±12.8; and PSI, 103.8±12.9 (Table 3).
Results of the Korean Wechsler Intelligence scale for children III, IV, V of the TD/TS and HC groups
A direct comparison between the 13 TD/TS participants assessed with K-WISC-IV and the 38 HC participants revealed significantly lower PRI scores in the TD/TS group (97.5±9.4) compared with the HC group (106.3±10.4, P=0.001). No significant differences were found in FSIQ, VCI, WMI, or PSI between groups (Table 3).
2) Child behavior checklist
T-scores from the K-CBCL 6–18 are summarized in Table 4. The TD/TS group scored significantly higher than the HC group on internalizing, externalizing, and total problem scales (all P<0.01). Similarly, all syndrome subscales—including anxious/depressed, withdrawn/depressed, somatic complaints, social problems, thought problems, attention problems, rule-breaking behavior, and aggressive behavior were significantly elevated in the TD/TS group. DSM-oriented scales also showed significantly higher T-scores in the TD/TS group for depressive problems, anxiety problems, somatic problems, ADHD, oppositional defiant problems, and conduct problems. On the 2007 problem scales, obsessive-compulsive problems and stress problems were significantly higher in the TD/TS group, while no group difference was found for sluggish cognitive tempo. Scores from the activities, social, and school competence scales did not differ significantly between groups (Fig. 1).
Results of the Korean Child Behavior Checklist for ages 6–18 profiles in TD/TS and HC groups
(A, B) Mean T-scores of the Korean Child Behavior Checklist for Ages 6–18 in the tic disorder (TD)/Tourette syndrome (TS) and healthy controls (HC) groups. IP, internalizing problems; EP, externalizing problems; A/D, anxious/depressed; W/D, withdrawn/depressed; SC, somatic complaints; SP, social problems; TP, thought problems; AP, attention problems; RBB, rule-breaking behavior; AB, aggressive behavior; Dep, depressive problems; Anx, anxiety problems; Som, somatic problems; AD/H, attention-deficit/hyperactivity; Opp, oppositional defiant problems; Con, conduct problems; OC, obsessive-compulsive problems; Slu, sluggish cognitive tempo.
The distribution of participants classified as ‘normal,’ ‘borderline clinical,’ or ‘clinical’ is also shown in Table 4. For analysis, the borderline and clinical ranges were combined as the ‘problem group.’ The TD/TS group had significantly higher proportions in the problem group for internalizing, externalizing, and total problems (all P<0.05). By syndrome subscales, significantly higher problem-group proportions were observed in anxious/depressed (P=0.004), somatic complaints (P=0.023), and thought problems (P<0.001). For DSM-oriented scales, the TD/TS group had significantly higher proportions in anxiety problems (P=0.006), somatic problems (P=0.023), and ADHD (P=0.023). On the 2007 scales, problem-group proportions were significantly higher in obsessive-compulsive problems (P=0.013) and stress problems (P=0.003). No significant differences were found in competence scale scores.
3) Memory and executive function tests
Results from the Rey–Kim Memory Test, STROOP, and CCTT are summarized in Table 2. The mean MQ was significantly higher in the HC group compared with the TD/TS group (P=0.042). T-scores for CCTT-1, CCTT-2, and the interference measure did not differ significantly between groups. In the STROOP test, word reading and color-word naming scores showed no group differences. However, the HC group had significantly higher color naming scores (P=0.031) and significantly lower interference scores (P=0.021) than the TD/TS group.
4) ADHD rating scale
In the TD/TS group (n=35), the mean K-ARS-IV score was 11.3±7.7, with 17.1% (n=6) exceeding the clinical cutoff (≥19, parent-report). In the HC group (n=38), the mean score was 5.8±5.9, with 2.6% (n=1) above the cutoff (Table 2). Total scores, as well as Inattention and Hyperactivity/Impulsivity sub-scores, were significantly higher in the TD/TS group. However, the proportion of individuals exceeding the clinical cutoff did not differ significantly between groups (P=0.050).
5) Social maturation scale and depression index
In the TD/TS group, the mean SA on the SMS was 10.1±2.0 years, compared with a chronological age of 9.5±2.1 years. The mean SQ was 103.0±6.2 (n=27). The mean CDI-2 score in the TD/TS group (n=34) was 6.7±4.8, with no participants classified in the ‘mild depression’ (22–25) or ‘moderate depression’ (26–28) ranges. The HC group did not undergo SMS or K-CDI assessments (Table 2).
Discussion
In the present study, we comprehensively examined the neurocognitive and behavioral profiles of children with TD/TS, comparing them with HC. To minimize bias from coexisting conditions, we included only participants with normal-range IQs and excluded those with serious neurological or physical disorders. The TD/TS group demonstrated significantly lower non-VIQ, behavioral functioning, executive function, and attention scores compared with the HC group, highlighting distinct differences between groups.
Within-group analysis showed that the mean FSIQ in the TD/TS group fell within the normal range (98.8±11.7), with VCI scores generally higher than nonverbal indices (POI, PRI, VSI) and psychomotor speed (PSI). Because different Wechsler test editions were administered across years, we referenced only mean scores rather than performing direct statistical comparisons. Comparisons with controls were conducted solely using the K-WISC-IV, revealing that the TD/TS group had significantly lower nonverbal reasoning (PRI) scores than HC (97.5±9.4 vs. 106.3±10.4, P=0.010).
These findings partially align with previous studies. For example, Wanderer et al. [19] observed higher VCI and lower PSI scores in children with only chronic TD or only OCD compared with German standardization data, although the results did not reach statistical significance. Debes et al. [21] found that HC had higher PIQ and FSIQ scores than matched TS participants, while the TS group showed higher VIQ scores on the WISC-III. Conversely, Rizzo et al. [29] reported no significant FSIQ differences between TS-only and control groups.
In the present study, FSIQ did not differ significantly between TD/TS and HC groups. However, PRI scores were notably lower in the TD/TS group. The PRI measures nonverbal reasoning and categorization abilities based on accurate and rapid performance of visually presented tasks, and performance is influenced by visuomotor coordination. Reduced PRI scores suggest that children with TD/TS may have weaknesses in visuospatial reasoning and fine motor skills, with decreased speed and accuracy on tasks requiring these abilities.
Although the proportion of individuals exceeding the ADHD cutoff on the K-ARS-IV did not significantly differ between TD/TS and HC groups, mean K-ARS-IV scores were significantly higher in the TD/TS group. Relative deficits in attention and impulse control, as well as increased error rates, may have negatively influenced PRI performance.
Notably, lower PRI scores may also reflect intrinsic neurocognitive characteristics of TD/TS, including difficulties with visuospatial processing, attentional regulation, and nonverbal problem-solving. Further research with larger samples and detailed psychiatric evaluations will be necessary to better characterize these features.
The CBCL assesses a wide range of behavioral and adaptive problems in children. In this study, the proportion of participants within borderline and clinical ranges for internalizing problems, externalizing problems, total problems, anxious/depressed problems, somatic complaints, thought problems, anxiety problems, somatic problems, ADHD, obsessive-compulsive problems, and stress problems on the CBCL 6–18 was significantly higher in the TD/TS group than in the HC group. A prior study by Cui et al. [22] demonstrated positive correlations between functional impairments (subscales of the Yale Global Tic Severity Scale) and both thought problems and rule-breaking behavior, suggesting that behavioral and emotional difficulties may exacerbate the functional impairment associated with TS. The CBCL thought problems scale evaluates behaviors reflecting difficulties in cognitive processing, often linked to disorganized or irrational thinking, preoccupations, or unusual thoughts. Items may include obsessive thoughts, compulsions, unusual ideas or behaviors, self-harm, hallucinations, nervous twitching, excessive body-picking, inappropriate sexual behaviors in public, compulsive hoarding, sleepwalking or sleep-talking, and sleep disturbances. The scale is especially relevant for identifying children at risk for more serious psychiatric conditions, such as obsessions, autistic features, and psychosis [30,31]. Many individuals with tics, particularly older children, become aware of premonitory urges—feelings of tightness, tension, or itching associated with discomfort or anxiety—that are relieved only by performing a tic. As awareness of these urges increases, patients with TS may exert partial voluntary control over their tics. However, resisting the mounting tension of premonitory urges often results in mental and physical exhaustion, which can be more impairing and distracting than the tics themselves [32]. In this study, the TD/TS group exhibited higher CBCL scores across multiple domains compared with healthy children. It is plausible that the cognitive and emotional burden of suppressing tics manifests as behavioral and emotional problems. Because such problems may also be influenced by comorbid conditions like ADHD or OCD, future research with larger samples and subgroup analyses is warranted.
The CCTT and STROOP tests evaluate different aspects of executive function. Executive function refers to a set of cognitive processes that enable behavioral regulation through cognitive control [26,27]. Selecting and maintaining attention on relevant behaviors is critical for achieving goals, and deficits in these processes are commonly reported in children with ADHD. Both tests are validated measures of executive function in pediatric populations. In this study, the CCTT did not reveal significant group differences. However, on the STROOP test, the TD/TS group demonstrated a significantly lower T-score for color naming and a higher interference T-score compared with the HC group. The interference score reflects the performance difference between the color-word naming and word reading tasks. It measures cognitive flexibility and selective attention by evaluating a child’s ability to name the ink color of a word, despite the word itself representing a conflicting color. A higher interference score indicates greater difficulty in managing cognitive conflict and suggests impairments in cognitive control, attentional regulation, and suppression of automatic reading responses [29]. Although prior research findings have been inconsistent, several studies suggest that executive dysfunction in TS is specifically associated with reduced inhibitory control and impaired cognitive flexibility [33,34]. The present results also indicate challenges in cognitive flexibility and selective attention among children with TD/TS, implying that they may experience difficulty suppressing automatic responses and maintaining cognitive control [35].
A total of 17.1% (n=6) of the TD/TS group scored above the cutoff for ADHD on the K-ARS (≥19). Previous studies have reported that 50%–60% of children with tics present with comorbid ADHD. For example, Rizzo et al. [7] found that children in the TS+ADHD subgroup exhibited more behavioral problems and poorer quality of life across all subscales compared with the TS-only group and HC [36]. Similarly, Roessner et al. [37] reported that ADHD was associated with deficits in neuropsychological performance, particularly in comorbid TD+ADHD cases [38]. The present findings also confirmed that approximately 17% of the TD/TS group had clinically diagnosed ADHD. Attention problems in these children may be related not only to comorbidity but also to the distracting effects of motor and vocal tics, as well as the mental effort required to suppress tics. As demonstrated in previous research, comorbid ADHD can exacerbate cognitive dysfunction, underscoring the importance of timely diagnosis and management of ADHD in children with TD/TS to support optimal cognitive development [38].
This study has some limitations. The sample size of both the TD/TS and HC groups was relatively small, warranting confirmation in larger cohorts. Selection bias may also have influenced the results, as neurocognitive and behavioral assessments are more likely to be performed in children with more severe TD/TS symptoms or clinical concerns about cognitive or emotional functioning.
In summary, children with TD/TS showed no significant differences in FSIQ compared with HC but exhibited relative weaknesses in the PRI and difficulties in executive functioning, particularly in tasks requiring attention and cognitive flexibility. Behavioral assessments revealed a higher prevalence of behavioral and emotional problems, and approximately 17% of children with TD/TS were diagnosed with comorbid ADHD.
In conclusion, clinicians caring for pediatric patients with TD/TS should be attentive to comorbid conditions such as ADHD, behavioral problems, and emotional difficulties, and should recognize patterns of strengths and weaknesses on WISC performance. Intellectual ability plays an important role in cognitive functioning, social adaptation, and school achievement. A thorough understanding of the neurocognitive and behavioral characteristics of children with TD/TS can inform the development of tailored interventions and contribute to improved treatment outcomes and social adjustment.
Although cognitive weaknesses or behavioral problems may not be immediately apparent at diagnosis, routine incorporation of cognitive and behavioral assessments into the diagnostic and treatment process is recommended for children with TD/TS.
Notes
Conflicts of interest
No potential conflict of interest relevant to this article was reported.
Author contribution
Conceptualization: MP and JHM. Data curation: MP and MSK. Formal analysis: MP, SR, and JHM. Funding acquisition: JHM. Methodology: MP and SR. Project administration: JHM. Writing - original draft: MP. Writing - review & editing: JHM.
Acknowledgments
This study was funded by RS-2023-00267049 by national research fund.