“Just Right” Perceptions and Obsessive-Compulsive Symptoms in Tourette Syndrome and Chronic Tic Disorder: Implications for Tourettic Obsessive-Compulsive Disorder

Abstract

Objectives

Perceptions that something is not “just right” and feelings of incompleteness are forms of premonitory urges that extend beyond simple bodily sensations; they involve subjective interpretations of those sensations and may therefore be regarded as mental phenomena. These phenomena may precede tics but can also trigger compulsive behaviors. Investigating these phenomena is essential for understanding intermediate clinical phenotypes between tic disorders and obsessive-compulsive disorder (OCD).

Methods

We retrospectively reviewed the medical records of 71 patients older than 10 years with tic disorders who attended the department of psychiatry at a hospital. Clinical assessments included the Korean versions of the Premonitory Urge for Tics Scale, Yale Global Tic Severity Scale, and (Children’s) Yale-Brown Obsessive-Compulsive Scale.

Results

Among patients with Tourette syndrome, 71.21% reported experiencing “just right” perceptions. Both the frequency and severity of “just right” perceptions were significantly greater in patients with tic disorders and comorbid OCD (n=8) than in those without comorbid OCD (n=63). In addition, the severity of premonitory urges showed a significant correlation with the severity of obsessive-compulsive symptoms.

Conclusion

“Just right” perceptions are not only an intrinsic characteristic of tic disorders but are also associated with repetitive behaviors in OCD. These results provide preliminary clinical support for Tourettic OCD as an intermediate phenotype between tic disorders and OCD.

INTRODUCTION

Tics are characterized by sudden, rapid, repetitive, and nonrhythmic motor movements or vocalizations. Tic disorders, classified as neurodevelopmental disorders, fall into three categories according to the type and duration of tics [1]. Tourette syndrome is diagnosed when multiple motor tics and at least one vocal tic have been present for more than one year, with onset before age 18. Chronic tic disorder is diagnosed when either motor or vocal tics persist for more than one year. When motor or vocal tics have been present for less than one year, the condition is diagnosed as provisional tic disorder. The term “provisional” is used because the subsequent clinical course cannot be predicted at the time of diagnosis.

Many patients with tic disorders perform tics in response to premonitory urges, such as itching, pressure, or tension, which are temporarily relieved following the execution of the tic [2]. Premonitory urges can occur throughout the body and are particularly common in the face, neck, shoulders, arms, palms, and midline of the abdomen. Premonitory urges are often described as feelings of stiffness or tension, a buildup of energy that causes distress unless it is discharged, or a compelling urge for movement in the muscles, joints, or other body parts. Some patients also report “just right” perceptions or feelings of incompleteness [3]. As performing a tic often relieves tension and produces a sense of relief, many patients describe their tics as intentional. However, because tics can be voluntarily suppressed for a limited period, it is more appropriate to regard them as involuntary or semi-voluntary movements [4].

“Just right” perceptions and feelings of incompleteness differ from most other forms of premonitory urges. As these two premonitory urges involve subjective interpretations superimposed on physical sensations, they may be regarded as perceptually tinged mental phenomena [3]. For example, some patients with tic disorders may repeatedly adjust the position of their neck because they feel it is not centered, or continuously wiggle their toes because of a sensation that their socks are caught on them. Some may repeatedly recite words or entire sentences until the pitch or intonation sounds “just right.” Thus, “just right” perceptions may occur in the visual, auditory, or tactile modalities, with visual experiences being the most common, followed by tactile and auditory experiences. According to Leckman et al. [3], 44% of patients with Tourette syndrome report “just right” perceptions, engaging in repetitive behaviors until they achieve a sense that things feel “just right.”

Obsessive-compulsive disorder (OCD) is generally defined by the presence of obsessions and compulsions. However, repetitive behaviors may also occur in the absence of obsessions. For example, a child may be able to fall asleep only after arranging dolls on both sides of the bed, reading the same storybook, and hearing their mother say good night thrice before bedtime. Although the child may feel uncomfortable when these habitual and ritualistic behaviors cannot be performed, he or she is not distressed by obsessions. Another type of repetitive behavior that occurs without obsessions is driven by bodily discomfort, referred to as sensory phenomena, which are similar to the “just right” perceptions reported by patients with tic disorders [5]. For example, a patient may repeatedly adjust the position of a belt because it does not seem centered, or rub the surface of a desk with the fingertips until the desired “just right” tactile sensation is achieved. A patient may also repeatedly open and close a door until the resulting clicking sound feels satisfactory. In summary, a substantial proportion of patients with OCD perform compulsions in response to sensory phenomena, in a manner similar to patients with tic disorders.

Ultimately, tic disorders and OCD are similar in that subjective sensory-related experiences can trigger repetitive behaviors. Although tics are generally less complex than compulsions and are not performed to neutralize obsessions, complex tics and compulsions are often difficult to distinguish. Indeed, 30%–50% of patients with Tourette syndrome have comorbid OCD [6]. Ferrão et al. [5] reported that 65% of patients with OCD experience at least one type of sensory phenomenon. In 1994, Leckman et al. [3] reported that many patients with Tourette syndrome have comorbid OCD or obsessive-compulsive symptoms and that these individuals report “just right” perceptions more frequently than do patients diagnosed with Tourette syndrome alone. Miguel et al. [7] also suggested that although patients with OCD experience obsessions accompanied by anxiety, the presence of comorbid Tourette syndrome is associated with an increased frequency of sensory stimuli that trigger compulsions, reaching levels comparable to those reported by patients with Tourette syndrome. Woods et al. [8] observed a correlation between the severity of premonitory urges and OCD symptoms. In Kano et al.’s [9] study, the total score on the Premonitory Urge for Tics Scale (PUTS) was significantly correlated with aggression and symmetry scores among the various OCD dimensions assessed using the Dimensional Yale-Brown Obsessive-Compulsive Scale.

In addition, tic disorders and OCD share parts of the cortico-striato-thalamo-cortical loop, which consists of multiple parallel subcircuits, including the sensorimotor, associative, and limbic circuits [10]. The upregulation and downregulation of these circuits constitute the neurophysiological basis of Tourette syndrome and OCD. In both disorders, patients lose top-down control and exhibit excessive responses to sensory or emotional stimuli. By performing tics or compulsions, they obtain a reward in the form of relief from premonitory urges or anxiety. In 2023, Shitova et al. [11] argued in their review that both tic disorders and OCD are associated with abnormalities of the cortico-striato-thalamo-cortical loop and proposed an imbalance between excitatory and inhibitory signaling within these circuits as a key pathophysiological mechanism.

Tic disorders and OCD are hypothesized to be conditions on a continuum, sharing many features such as clinical presentation and pathophysiology [10]. Accordingly, the sensory phenomena reported by both patients with tic disorders and those with OCD may serve as a link between the two disorders and may therefore provide clues for testing this hypothesis. The present study was designed to test the following three hypotheses.

Hypothesis 1: many patients with Tourette syndrome report not only premonitory urges limited to bodily sensations but also “just right” perceptions, a type of mental phenomenon.

Hypothesis 2: the frequency and severity of “just right” perceptions are higher in patients with comorbid tic disorder and OCD than in those with tic disorder alone.

Hypothesis 3: the severity of premonitory urges is correlated with the severity of OCD.

METHODS

Participants and procedures

This study included children, adolescents, and adults older than 10 years who visited the Department of Psychiatry at Jeonbuk University Hospital between July 2017 and July 2022 and were diagnosed with Tourette syndrome or chronic tic disorder by board-certified psychiatrists according to the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition [1]. A total of 71 participants who had completed treatment and had not visited the hospital during the preceding two years were included. To identify eligible participants, the investigators retrospectively reviewed patients’ medical records in reverse chronological order, from July 2022 back to July 2017. Children, adolescents, and adults older than 10 years who had been diagnosed with Tourette’s or chronic tic disorder and did not meet any of the exclusion criteria were consecutively enrolled. No additional screening procedures apart from the review of medical records for eligibility were performed; therefore, no patients were excluded after screening.

Among the enrolled patients, most had completed treatment following remission of their symptoms (n=49). The remaining patients had either been transferred to other institutions for personal reasons, such as relocation or difficulties related to travel distance (n=13), or had been lost to follow-up despite requiring continued treatment (n=9). Although many patients initiated treatment at our institution, some were transferred to our institution while undergoing treatment at other hospitals. All interviews with the patients and their caregivers were conducted by a board-certified psychiatrist during routine clinical visits. The assessments were administered as clinically indicated during either the initial visit or a follow-up visit; therefore, assessment timing varied among patients. Of the 71 patients, 51 were assessed at their initial visit. Among these patients, 21 were already receiving pharmacological treatment at another hospital at the time of referral. The remaining 20 patients were assessed during the course of treatment. No patients were assessed after treatment had been completed. Patients were excluded if they had congenital genetic disorders, neurological diseases, a clear history of acquired brain injury, schizophrenia, bipolar disorder, major depressive disorder, neurological conditions such as seizure disorders, developmental disorders including intellectual disability or autism spectrum disorder, alcohol or substance dependence, or concomitant language disorders or severe learning disabilities. All documents required for institutional review board review, including the retrospective study application form and justification for a waiver of informed consent, were submitted. The study was approved by the Institutional Review Board of Jeonbuk University Hospital on May 30, 2025 (IRB No. 2025-05-067). The requirement for informed consent was waived because this study involved a retrospective review of medical records.

Measures

Korean form of the PUTS

Developed by Woods et al. [8] in 2005 to assess premonitory urges in patients with tic disorders, the PUTS is a self-report instrument that relies on patients’ subjective reports rather than clinicians’ observations to generate scores. The PUTS consists of nine items, each rated on a 4-point Likert scale ranging from 1 (“not at all true”) to 4 (“very much true”), with higher scores indicating greater severity of premonitory urges. The PUTS total score is calculated by summing the scores of all nine items, yielding a range from 9 to 36. This score reflects various aspects of premonitory urges, including their type, presence, and frequency, and the qualitative characteristics of the urges that are relieved after tic completion. Although the PUTS has demonstrated generally good reliability and validity, its internal consistency has been reported to be low in children younger than 10 years. For this reason, the present study included only participants older than 10 years. The Korean version of the PUTS was standardized by Kim et al. [12] in 2020.

Korean form of the Yale Global Tic Severity Scale

The Yale Global Tic Severity Scale (YGTSS) is a clinician-rated instrument developed by Leckman et al. [13] in 1989 to assess tic symptoms. The clinician first obtains subjective reports from patients and their caregivers and then gathers information as objectively as possible through additional questioning, clinical judgment, and the clarification or modification of reported information. The YGTSS evaluates five dimensions of symptoms separately for motor and vocal tics: number, frequency, intensity, complexity, and interference. Each dimension is rated on a scale from 0 to 5, reflecting the quantitative and qualitative characteristics of tic symptoms. The scores for these dimensions are summed to generate a tic severity score ranging from 0 to 50. In the next step, a functional impairment score ranging from 0 to 50, in 10-point increments, is determined by assessing the extent to which tic symptoms disrupt daily functioning in domains such as self-esteem, family life, social acceptance, school functioning, and job performance. The YGTSS total score is calculated by summing the tic severity and impairment scores. The Korean version of the YGTSS was standardized by Chung et al. [14] in 1998 and demonstrated acceptable reliability and validity.

Korean forms of the Y-BOCS and Children’s Y-BOCS

The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and Children’s Y-BOCS (CY-BOCS) are semi-structured clinician-rated instruments developed by Goodman et al. [15] to assess the severity of OCD. Rather than evaluating the content or specific types of obsessive-compulsive symptoms, the (C)Y-BOCS assesses the impact of these symptoms across five domains: time spent, interference with daily functioning, subjective distress, resistance, and perceived control. For both obsessions and compulsions, clinicians rate each of these five domains on a scale from 0 to 4, yielding a total score ranging from 0 to 40, with higher scores indicating greater OCD severity. The CY-BOCS is used for children and adolescents aged 18 or younger and incorporates information obtained from both the patient and caregiver. Although it is largely identical to the Y-BOCS, the wording and interview procedures have been modified to be developmentally appropriate, taking into account children’s cognitive development level and language comprehension. The Korean version of the CY-BOCS was standardized by Chung et al. [16] in 2000.

Statistical analysis

Fisher’s exact test was used to compare the proportion of participants reporting “just right” perceptions between those with tic disorder and comorbid OCD and those with tic disorder alone. Among the 71 participants, only eight had comorbid OCD, and all eight reported “just right” perceptions, resulting in a zero cell in the contingency table. With such a small comorbid group, even a minor change in classification or missing data could substantially affect the results. Therefore, the risk ratio and its 95% confidence interval (CI) were additionally calculated as measures of effect size. Similarly, the Mann–Whitney U test was used to compare mean scores on Item 4 of the PUTS (“just right” perceptions) between the two groups. Although the tic disorder-only group consisted of 63 participants, the comorbid tic disorder and OCD group included only eight participants. Accordingly, the Shapiro–Wilk test was performed to assess the normality of score distributions in each group. As neither group met the assumption of normality, nonparametric statistical methods were applied. In addition, the combined scores of PUTS Items 4 and 5 (“feelings of incompleteness”) were compared between the two groups using the Mann–Whitney U test following the same statistical procedure. To address the statistical uncertainty arising from the small size of the comorbid OCD group, Cliff’s δ was calculated as an effect-size measure, together with its 95% CI, for both comparisons.

Pearson correlation analyses were conducted to examine whether positive correlations existed between the PUTS and YGTSS total scores, as well as between the PUTS and (C)Y-BOCS total scores. Additionally, the correlation of the summed scores of PUTS Items 4 and 5 with the YGTSS and (C)Y-BOCS total scores was analyzed. Furthermore, partial correlation analyses were conducted to examine the association between the combined score of PUTS Items 4 and 5 and the (C)Y-BOCS total score after controlling for the YGTSS total score. The results were then compared with those obtained without controlling for tic severity to determine whether adjustment for the YGTSS total score altered the observed relationship. As the PUTS, YGTSS, and (C)Y-BOCS total scores did not meet the assumption of normality, Spearman rank correlations were additionally calculated as sensitivity analyses. Of the 71 participants, 59 children and adolescents aged 18 or younger were assessed using the CY-BOCS, whereas the 12 adults were assessed using the Y-BOCS. Given that the Y-BOCS and CY-BOCS assess the same aspects of obsessive-compulsive symptoms, including time spent on symptoms, interference with daily functioning, subjective distress, resistance, and perceived control, and use identical item-rating ranges and the same total-score range of 0–40, their raw total scores were considered comparable. We did not interpret the scores using age-specific normative values or apply instrument-specific cutoffs to classify participants into severity categories because such criteria could assign different clinical meanings to the same raw score in children and adults. Instead, the total scores were used as continuous measures of the relative severity of obsessive-compulsive symptoms across participants. Therefore, the Y-BOCS and CY-BOCS scores were combined and reported as the (C)Y-BOCS total score. All statistical analyses were performed using SPSS software (version 18.0; SPSS Inc.), except for Cliff’s δ, which was calculated using R (Version 4.6.1; https://www.r-project.org/).

RESULTS

Demographic and clinical characteristics

The study included 71 participants aged 10–44 years, with a mean age of 15.11 years (standard deviation [SD]=6.86 years). Of these, 61 (85.91%) were male and 10 (14.09%) were female. Among the 71 participants, 66 (92.96%) were diagnosed with Tourette syndrome and 5 (7.04%) with chronic tic disorder. Nearly half of the participants (n=32, 45.07%) had at least one comorbid condition. Specifically, 5 participants (7.04%) had OCD, 24 (33.80%) had attention-deficit/hyperactivity disorder (ADHD), and 3 (4.23%) were diagnosed with both OCD and ADHD (Table 1). The mean PUTS score was 19.03 (SD= 6.18), ranging from 9 to 31. The mean YGTSS score was 35.59 (SD=18.50), with scores ranging from 4 to 88. The mean score on the (C)Y-BOCS was 7.44 (SD=9.34), ranging from 0 to 35.

Table 1.

Demographic and clinical characteristics

	Subjects (n=71)
Age (yr)	15.11±6.86
Sex
Male	61 (85.91)
Female	10 (14.09)
Diagnosis
Tourette’s disorder	66 (92.96)
Chronic motor or vocal tic disorder	5 (7.04)
Comorbidities	32 (45.07)
OCD	5 (7.04)
ADHD	24 (33.80)
OCD+ADHD	3 (4.23)

Values are presented as mean±standard deviation or number (%). ADHD, attention-deficit/hyperactivity disorder; OCD, obsessive-compulsive disorder.

In addition, 61 of the 71 participants (85.92%) were receiving at least one psychotropic medication. Depending on their diagnoses, participants were prescribed antipsychotic medications such as aripiprazole and risperidone; selective serotonin reuptake inhibitors (SSRIs) such as escitalopram, sertraline, and fluoxetine; and ADHD medications such as methylphenidate, atomoxetine, and clonidine. A detailed breakdown of the specific medications prescribed is provided separately (Table 2).

Table 2.

Psychotropic medications use by diagnostic group

Diagnosis	n	Antipsychotics			SSRI			ADHD medications		α2 agonist
		Aripiprazole	Risperidone	Pimozide	Escitalopram	Fluoxetine	Sertraline	Methylphenidate	Atomoxetine	Clonidine
TS	35	26 (74.29)	5 (14.29)	1 (2.86)	5 (14.29)	-	-	-	-	2 (5.71)
TS+OCD	5	4 (80.00)	4 (80.00)	-	1 (20.00)	2 (40.00)	2 (40.00)	-	-	-
TS+ADHD	23	18 (78.26)	3 (13.04)	-	2 (8.70)	1 (4.35)	1 (4.35)	8 (34.78)	7 (30.43)	2 (8.70)
TS+OCD+ADHD	3	2 (66.67)	3 (100)	-	1 (33.33)	1 (33.33)	2 (66.67)	1 (33.33)	1 (33.33)	1 (33.33)
CTD	4	2 (50.00)	-	-	-	-	-	-	-	-
CTD+ADHD	1	-	-	-	-	-	-	1 (100)	-	-
Total	71	52 (73.24)	15 (21.13)	1 (1.41)	9 (12.68)	4 (5.63)	5 (7.04)	10 (14.08)	8 (11.27)	5 (7.04)

Values are presented as number (%). ADHD, attention-deficit/hyperactivity disorder; CTD, chronic tic disorder; OCD, obsessive-compulsive disorder; SSRI, selective serotonin reuptake inhibitor; TS, Tourette syndrome.

Prevalence of “just right” perceptions in patients with Tourette syndrome

Among the 66 participants diagnosed with Tourette syndrome, 47 (71.21%) reported experiencing “just right” perceptions, whereas only 1 of the 5 participants (20.00%) diagnosed with chronic tic disorder reported such experiences. The proportion of participants reporting “just right” perceptions differed significantly between the two groups (Fisher’s exact test, p=0.035).

Frequency and severity of “just right” perceptions in patients with tic disorder and comorbid OCD

Among participants with tic disorder and comorbid OCD, 100% reported “just right” perceptions, compared with 63.49% of those with tic disorder alone. The difference between the two groups was statistically significant (Fisher’s exact test, p=0.047). Participants with comorbid OCD were 1.58 times as likely to report “just right” perceptions as those with tic disorder alone (risk ratio=1.58; 95% CI, 1.31–1.90). Similarly, the tic disorder group with comorbid OCD had higher scores on PUTS Item 4, which assesses “just right” perceptions, than did the tic disorder-only group (Mann–Whitney U=148.00, p=0.049). The effect size for the group difference was moderate (Cliff’s δ=0.41; 95% CI, 0.12–0.64). When the scores of PUTS Items 4 and 5 were summed, the tic disorder group with comorbid OCD again had higher scores than the tic disorder-only group (Mann–Whitney U=143.00, p=0.043), with a moderate effect size (Cliff’s δ=0.43; 95% CI, 0.08–0.69) (Table 3).

Table 3.

Comparison of PUTS Item 4 and combined Items 4+5 scores between tic disorder only and tic disorder+OCD groups using Mann–Whitney U test

Measure	Group	n	Median	IQR (Q1-Q3)	Z	U	p	Cliff’s δ (95% CI)
PUTS Item 4	Tic disorder only	63	2	1.00-3.00	-1.970	148	0.049	0.41 (0.12-0.64)
	Tic disorder+OCD	8	3	2.25-3.00
PUTS Items 4+5	Tic disorder only	63	4	2.00-6.00	-2.019	143	0.043	0.43 (0.08-0.69)
	Tic disorder+OCD	8	5.5	4.25-6.75

CI, confidence interval; IQR, interquartile range; OCD, obsessive-compulsive disorder; PUTS, Premonitory Urge for Tics Scale.

Relationships between PUTS and (C)Y-BOCS total scores, and between PUTS and YGTSS total scores

A significant positive correlation was observed between the PUTS and (C)Y-BOCS total scores (r=0.56, p<0.01). The PUTS total score was also positively correlated with the YGTSS total score, and this relationship was statistically significant (r=0.42, p<0.01). Furthermore, the correlation between the combined score of PUTS Items 4 and 5 and the YGTSS total score was statistically significant; however, the positive linear relationship was weak (r=0.26, p=0.029) (Table 4). These results suggest that tic severity is associated not only with the sensory phenomena assessed by PUTS Items 4 and 5 but also with other types of premonitory urges. In addition, the combined scores of PUTS Items 4 and 5 showed a relatively strong positive correlation with the (C)Y-BOCS total score (r=0.47, p=0.001). After controlling for the YGTSS total score, a positive linear relationship between these two variables persisted (r=0.43, p=0.004) (Table 4). This suggests that the severity of the premonitory urges assessed by PUTS Items 4 and 5 is independently associated with OCD severity, regardless of tic severity. Spearman rank correlation analyses conducted as sensitivity analyses produced results generally consistent with those of the Pearson correlation analyses. The PUTS total score was significantly correlated with both the YGTSS total score (ρ=0.38, p<0.001) and the (C)Y-BOCS total score (ρ=0.59, p<0.001). The combined score of PUTS Items 4 and 5 was significantly correlated with the YGTSS total score (ρ= 0.24, p=0.048) and the (C)Y-BOCS total score (ρ=0.51, p< 0.001). The correlation between the YGTSS and (C)Y-BOCS total scores was not significant (ρ=0.09, p=0.546).

Table 4.

Pearson r correlations of PUTS total score and Items 4+5 with YGTSS and (C)Y-BOCS scores

	PUTS	PUTS	YGTSS	(C)Y-BOCS
		Items 4+5
PUTS	-	-	0.42**	0.56**
PUTS Items 4+5	-	-	0.26*	0.47** (0.43**)†
YGTSS	-	-	-	0.22
(C)Y-BOCS	-	-	-	-

^*p＜0.05; **p＜0.01; ^†partial correlation coefficient controlling for YGTSS total score is shown in parentheses. (C)Y-BOCS, (Children’s) Yale-Brown Obsessive-Compulsive Scale; PUTS, Premonitory Urge for Tic Scale; YGTSS, Yale Global Tic Severity Scale.

DISCUSSION

In 1980, Bliss et al. [17] reported the case of a patient with Tourette syndrome who had a 62-year history of illness and described the sensory experience preceding tics as a “preliminary sensation.” This was the first report of a subjective experience that triggers repetitive behaviors in relation to tic disorders, and numerous studies subsequently followed. Shapiro et al. [18] termed the uncomfortable bodily sensations experienced by patients with Tourette syndrome, involving the joints, bones, and muscles and relieved by performing tics, “sensory tics.” Subsequently, Leckman et al. [2] defined these bodily sensations as “premonitory urges.”

Research on similar phenomena in OCD had emerged much earlier. In 1903, Janet and Raymond [19] reported that feelings of bodily incompleteness could precede compulsive behaviors. Rasmussen and Eisen [20] observed that patients with OCD engaged in repetitive behaviors until they felt a sense of perfection. Subsequently, researchers began to describe the subjective experiences shared by tic disorders and OCD from an integrated perspective. In particular, Miguel et al. [21] argued that Tourette syndrome and OCD exist on a phenomenological continuum and proposed the term “sensory phenomena” to describe the uncomfortable bodily experiences shared by the two conditions.

In 2005, Mansueto and Keuler [22] described a clinical phenotype of OCD that failed to respond to standard treatments for the disorder, particularly exposure and response prevention and SSRI monotherapy. These patients were not troubled by anxiety about catastrophic outcomes; instead, they were preoccupied with sensory-based demands to feel “just right,” with a particular focus on symmetry, arrangement, position, balance, and touch. They engaged in repetitive behaviors in response to localized or generalized physical tension and feelings of incompleteness, and often exhibited early signs of sensory hypersensitivity, experiencing excessive distress from clothing labels, tight-fitting underwear, or uneven shoelaces. The obsessive-compulsive symptoms reported by these patients were atypical and represented a mixed presentation of tic disorder and OCD. Mansueto and Keuler [22] termed this “intermediate phenotype Tourettic OCD.”

Katz et al. [10] recently provided a comprehensive overview of Tourettic OCD. They noted that some patients engage in repetitive behaviors in response to bodily discomfort, without accompanying obsessions. The resulting behaviors are not as simple as typical tics but rather complex, multistep actions, such as tapping or touching objects in a particular manner, vocalizing phrases rather than simple sounds, or moving the right and left hands sequentially. According to the authors, these behaviors are closer to impulsions than to compulsions, as they are not primarily performed to reduce anxiety or driven by cognitive factors. Instead, patients continue the behaviors until they feel that a sensation is complete or “just right.” “Just right” perceptions may trigger tics, but they differ from other premonitory urges that are confined to bodily discomfort and are also distinct from obsessions, which involve anticipation of unfortunate events and are accompanied by anxiety. Premonitory urges are primarily physical and sensory in nature, whereas obsessions are emotional and cognitive; “just right” perceptions represent a mental phenomenon that lies somewhere between the two. Tourettic OCD is characterized by an earlier age at onset and a male predominance. Compared with typical OCD, cognitive dimensions in Tourettic OCD, such as checking, cleaning, and reassurance seeking, are less prominent, whereas sensory dimensions involving symmetry, exactness, and related behaviors such as rubbing, tapping, and touching are more common.

Based on this historical background, the present study formulated and tested three hypotheses regarding sensory phenomena. First, we proposed that a substantial proportion of patients with Tourette syndrome would report “just right” perceptions, a type of mental phenomenon. According to Leckman et al. [3], 44% of patients with Tourette syndrome experience “just right” perceptions. Other studies have reported that 30%–90% of patients with Tourette syndrome report “just right” perceptions [21,23,24]. Consistent with these results, 47 of the 66 participants (71.21%) diagnosed with Tourette syndrome in the present study reported “just right” perceptions. These results suggest that a mental phenomenon known to occur more frequently in the presence of comorbid OCD is also observed at a high rate among patients diagnosed with Tourette syndrome alone.

Second, we hypothesized that compared with patients diagnosed with tic disorder alone, patients with comorbid tic disorder and OCD would exhibit a higher frequency and greater severity of “just right” perceptions. In 1994, Leckman et al. [3] observed that the frequency of “just right” perceptions increased from 44% to 81% when OCD was comorbid with Tourette syndrome. Miguel et al. [21] reported similar findings in 2000. In 2023, Brandt et al. [25] compared patients with chronic tic disorders with and without comorbid OCD and found that a greater proportion of those with OCD reported “just right” perceptions. In 2014, Reese et al. [26] reported that patients diagnosed with Tourette’s or chronic tic disorder had significantly higher scores on PUTS Item 4, which assesses “just right” perceptions, when OCD was also present. The present results were consistent with those of previous investigations. Taken together, “just right” perceptions appear to represent both an intrinsic feature of tic disorders and a characteristic of OCD that becomes more prominent when the two disorders are comorbid.

These results should nevertheless be interpreted cautiously in light of the small number of participants with comorbid OCD. The prevalence of “just right” perceptions was 1.58 times higher in the tic disorder group with comorbid OCD than in the tic disorder-only group (risk ratio=1.58; 95% CI, 1.31–1.90). The between-group differences in PUTS Item 4 scores and combined scores on PUTS Items 4 and 5 were also moderate in magnitude (Cliff’s δ=0.41; 95% CI, 0.12–0.64 and Cliff’s δ=0.43; 95% CI, 0.08–0.69, respectively). However, the CIs for the two PUTS score comparisons were relatively wide, indicating limited precision associated with the small comorbid OCD group. Moreover, none of the three comparisons remained statistically significant after either Bonferroni or Holm correction for multiple comparisons. Therefore, these results should be regarded as preliminary rather than confirmatory, and replication in larger samples with adequate statistical power is required.

Third, we expected that the severity of premonitory urges would be correlated with the severity of OCD. Although premonitory urges are bodily discomforts that precede tics, some of them, particularly “just right” perceptions and feelings of incompleteness, are also sensory phenomena that can trigger compulsive behaviors [27]. This is supported by the fact that the PUTS has been shown to consist of two or three factors, with Item 4 (“just right” perception) and Item 5 (“feeling of incompleteness”) grouped into a single factor [12,28]. Accordingly, it may be inferred that the PUTS total score would be correlated with the (C)Y-BOCS total score. Indeed, Woods et al. [8] observed a significant correlation between total scores on the PUTS and (C)Y-BOCS across all age groups in children and adolescents aged 8–16 years diagnosed with Tourette’s or chronic tic disorder. Rajagopal and Cavanna [27] reported similar findings in a study of 108 adults with Tourette syndrome.

However, an examination of previous studies reveals inconsistent results [26,29], which could have two explanations. First, according to Leckman et al. [2], patients typically begin to recognize premonitory urges approximately three years after tic onset, with many patients beginning to report such urges around age 10. Banaschewski et al. [30] conducted interviews with children and adolescents aged 8–19 and observed that the proportion of individuals reporting premonitory urges increased with age. Woods et al. [8] reported that the internal consistency of the PUTS was lower among participants younger than 10 years and suggested that a certain level of cognitive ability is required to perceive and describe premonitory urges. Therefore, children younger than 10 years may underreport premonitory urges when completing the PUTS. Indeed, Steinberg et al. [29] examined the correlation between total scores on the PUTS and (C)Y-BOCS in children and adolescents with Tourette syndrome aged 7–15 and found a significant association only among those older than 10 years. For this reason, the present study included only participants older than 10 years and confirmed an association between the severity of premonitory urges and OCD. Second, because the PUTS includes several items that are not directly related to OCD, results regarding the correlation between total scores on the PUTS and (C)Y-BOCS may vary across studies. Openneer et al. [31] reported a significant correlation between PUTS and (C)Y-BOCS total scores in a sample of 656 children and adolescents aged 3–16; however, this association was no longer significant when PUTS scores were calculated without Items 4 and 5. In 2016, Brandt et al. [28] evaluated the reliability and validity of the PUTS in 22 adults and 40 children and adolescents with Tourette syndrome and found that only the scores of PUTS Items 3, 4, 5, and 9 were significantly correlated with the (C)Y-BOCS total scores. The authors suggested that while some PUTS items assess quantitative aspects such as the intensity, frequency, or duration of premonitory urges, others assess the qualitative characteristics of these sensations. Sensations such as “just right” perceptions and feelings of incompleteness were considered psychological components of premonitory urges that reflect their qualitative aspects. Accordingly, the authors argued that any correlation between PUTS and Y-BOCS total scores is likely attributable primarily to these two items, and the correlation would be substantially reduced or disappear when these item scores are excluded from the PUTS total score.

The strengths of the present study are as follows. First, to our knowledge, this is the first study to analyze the frequency and severity of “just right” perceptions in a Korean sample in order to examine the relationship between tic disorders and OCD by conceptualizing “just right” perceptions as a type of mental phenomenon. The obtained values fell within the range reported in previous studies, suggesting that they are reliable and may be representative of Korean patients. In addition, while sensory phenomena may be reported differently across cultures and languages, our results replicate those of previous international studies, suggesting that the sensory-based continuum between tic disorders and OCD is a universal phenomenon. Second, because only participants older than 10 years were included, we were able to analyze a sample capable of recognizing and reporting premonitory urges. As a result, the study clearly demonstrates the correlation between PUTS and (C)Y-BOCS total scores, for which previous studies have reported inconsistent results. This result supports the view that tic disorders and OCD are closely linked by mental phenomena such as “just right” perceptions and feelings of incompleteness. Third, the present study cited influential studies that explored sensory phenomena in patients with tic disorders and OCD. Given that many of these studies included sample sizes of 40–60, the sample of 71 participants in the present study can be considered at least above average in size.

Despite these strengths, the present study has several limitations. First, because the sample size of the smaller group was limited, nonparametric methods were used when comparing frequencies and scores between the two groups. Future studies with larger samples and adequate statistical power would help improve the generalizability of the results.

Second, only 12.12% of patients with Tourette syndrome had comorbid OCD, a proportion substantially lower than that generally reported in the literature. As the sample may not be fully representative of the target population, caution is warranted when interpreting the results. The lower rate of comorbid OCD among patients with Tourette syndrome in the present study may be explained by several factors. At tertiary hospitals, patients often choose a physician after reviewing the physician’s area of expertise. Therefore, patients with both tic and obsessive-compulsive symptoms may have chosen another hospital when obsessive-compulsive symptoms were their primary clinical problem. In addition, this study included only patients who had presented with tic symptoms as their chief complaint and had undergone Y-BOCS or CY-BOCS evaluation as part of routine clinical practice. As OCD was not thoroughly assessed in all patients with Tourette syndrome and this study was based on a retrospective review of medical records, previously treated obsessive-compulsive symptoms or symptoms that were not reported or were underreported may not have been identified. Furthermore, because enrollment was limited to patients who had completed treatment and had not visited the hospital during the preceding two years, patients with persistent symptoms requiring ongoing treatment may have been excluded. This selection criterion may have limited the representativeness of the sample, although its specific effect on the observed rate of comorbid OCD cannot be determined.

Third, patients receiving treatment were not analyzed as a separate subgroup. Medication status may influence tic severity, premonitory urges, and obsessive-compulsive symptoms. If some patients were assessed before treatment and others during or after treatment, the results may reflect treatment effects as well as underlying clinical relationships. Research on the effects of pharmacological treatments on premonitory urges and sensory phenomena is limited. Most studies have examined botulinum toxin, while studies of topiramate, ecopipam—a selective dopamine D1 receptor antagonist—and aripiprazole, which was taken by participants in the present study, have also been reported [32,33]. Although these treatments generally reduce tic severity, their effects on premonitory urges vary across studies, and no consistent therapeutic benefit has been established. Nevertheless, antipsychotics and SSRIs may substantially affect interoceptive processing, sensory gating, and the perception and interpretation of bodily sensations, thereby altering the subjective perceptual threshold for premonitory urges and potentially influencing PUTS scores. In addition, these medications may have reduced tic and obsessive-compulsive symptom severity, thereby lowering YGTSS and (C)Y-BOCS total scores and potentially altering the correlations between PUTS and YGTSS scores and between PUTS and (C)Y-BOCS scores. As medication type, combination regimens, dosage, and treatment duration varied considerably across participants and the sample size was limited, these effects could not be reliably controlled for in the statistical analyses. Future prospective studies should systematically collect medication data and compare medication-naïve, currently medicated, and previously medicated patients, while also classifying them by the types of medication used and by monotherapy or combination therapy to clarify the relationships between sensory phenomena, tic severity, and obsessive-compulsive symptoms.

CONCLUSION

The present study tested three hypotheses regarding the sensory phenomena shared by tic disorders and OCD. A substantial proportion of patients with Tourette syndrome reported “just right” perceptions, and both the frequency and severity of these perceptions were increased in patients with comorbid tic disorder and OCD. In addition, total PUTS scores were positively correlated with total (C)Y-BOCS scores. These results are consistent with a clinical continuum model linking tic disorders and OCD through sensory phenomena such as “just right” perceptions and feelings of incompleteness. They may also provide preliminary clinical support for considering Tourettic OCD as a phenomenological construct. Further prospective studies with larger samples and mechanistic measures are needed.

Funding Statement

Funding Statement None

Availability of Data and Material

The datasets generated and/or analyzed during the current study are not publicly available because they contain information that could compromise participant privacy but are available from the corresponding author on reasonable request.