Contextual Triggers and Tic Severity Across Life Periods: A Retrospective Analysis in Adults with Tic Disorders.

In tic disorders (TD), tic expression varies across the lifespan and as a function of contextual factors. This study explored connections between tic expression and contextual triggers across life periods in 74 adults (Mage = 23.2) with TDs. The Tic History and Coping Strategies form assessed retrospective self-reports of contextual antecedents, consequences, and tic severity during four life periods (middle school; 9th/10th grade; 11th/12th grade; college/work) and past month. Tics reportedly worsened during and after school in school-aged years and worsened in the evening during college/work years. Stress and anxiety were reported to consistently trigger tics across time. The impact of activities, places, and emotions did not differ across life periods. Attention-based consequences, most prevalent during middle school, were more common than escape- or avoidance-related consequences across all periods. Findings illuminate how contextual factors may influence tics across life periods and underscore the consistent impact of tic-triggering emotions and attention-related consequences.

Neurocognitive functioning in adults with trichotillomania: Predictors of treatment response and symptom severity in a randomized control trial.

Trichotillomania (TTM) is associated with impairments in response inhibition and cognitive flexibility, but it is unclear how such impairments relate to treatment outcome. The present study examined pre-treatment response inhibition and cognitive flexibility as predictors of treatment outcome, change in these domains from pre-to post-treatment, and associations with TTM severity. Participants were drawn from a randomized controlled trial comparing acceptance-enhanced behavior therapy (AEBT) to psychoeducation and supportive therapy (PST) for TTM. Adults completed assessments at pre-treatment (n = 88) and following 12 weeks of treatment (n = 68). Response inhibition and cognitive flexibility were assessed using the Stop Signal Task and Object Alternation Task, respectively. Participants completed the MGH-Hairpulling Scale. Independent evaluators administered the NIMH-Trichotillomania Severity Scale and Clinical Global Impressions-Improvement Scale. Higher pre-treatment TTM severity was associated with poorer pre-treatment cognitive flexibility, but not response inhibition. Better pre-treatment response inhibition performance predicted positive treatment response and lower post-treatment TTM symptom severity, irrespective of treatment assignment. Cognitive flexibility did not predict treatment response. After controlling for age, neither neurocognitive variable changed during treatment. Response inhibition and cognitive flexibility appear uniquely related to hair pulling severity and treatment response in adults with TTM. Implications for treatment delivery and development are discussed.

Sex Differences in Youth with Chronic Tic Disorder and Tourette Syndrome: Evaluation of Tic Severity, Psychological Profiles, and Quality of Life.

Background: Tourette syndrome (TS) and Chronic Tic Disorder (CT) are neurodevelopmental conditions involving motor and/or phonic tics. Youth with tics may encounter feelings of isolation, diminished self-esteem and quality of life, and academic difficulties. A growing body of scientific literature suggests sex differences in youth with tics, but findings have been mixed so far. Because symptom severity peaks around puberty, understanding sex differences in tic manifestations and associated symptoms during this critical period is essential. Therefore, we aimed to assess sex differences related to tic symptoms, action planning styles, quality of life, and externalizing/internalizing symptoms in youth with tics. Methods: Our sample consisted of 66 youths with tics (19 girls) aged 7-14 (mean = 10 years). Youths were assessed with clinical interviews, as well as self- and parent-reported inventories evaluating tic symptoms, psychological profiles, and quality of life. Results: While no differences in tic symptoms were found, girls exhibited lower functional inflexibility, reduced overall functional planning effectiveness, and higher impairment in the psychological well-being subscale than boys. Additionally, girls had reduced general life satisfaction and social self-esteem. Boys reported more explosive outbursts, higher levels of hyperactivity, and more difficulties with self-concept. Conclusions: Our analyses suggested differences in several manifestations associated with tics. This introduces new perspectives that refine our understanding of sex differences. A better understanding of sex differences in tic disorders may eventually improve outcomes for all individuals living with these conditions.

Exploring the psychometric properties of the premonitory urge for tics scale (PUTS) and its association with psychiatric symptoms in Chinese children with tic disorders.

BACKGROUND: The Premonitory Urge for Tics Scale (PUTS) is a common self-report measure of premonitory urges for patients with tic disorders. This study aims to evaluate the Chinese version of the PUTS (PUTS-C) and to explore its association with psychiatric symptoms in Chinese children diagnosed with tic disorders. METHODS: The psychometric evaluation involved 204 outpatients with tic disorders, aged 7-16 years, who were divided into two age groups: (7-10 years, n = 103; 11-16 years, n = 95). RESULTS: The PUTS-C demonstrated good internal consistency (McDonald'sω = 0.84) and two-week test-retest reliability (0.76). We observed a statistically significant correlation between the total PUTS-C score and various Yale Global Tic Severity Scale (YGTSS) subscales and total tic severity scores. The PUTS-C score also showed significant correlations with the Children Yale-Brown Obsessive Compulsive Scale (CY-BOCS), Screening Child Anxiety-Related Emotional Disorders (SCARED), and Children's Depression Inventory (CDI). Notably, premonitory urges independently predicted tic severity, beyond the influence of comorbid symptoms. A two-factor structure of the PUTS-C was identified in the total sample through factor analysis. CONCLUSIONS: The PUTS-C possesses acceptable validity and good reliability. It appears that premonitory urges in Chinese patients with tic disorders are associated with obsessive-compulsive symptoms, anxiety, and depression, but can independently predict tic severity. Specific PUTS-C factors possibly related to motor and vocal tics. Future research should continue to investigate age-related differences and the association with tics and other sensory symptoms.

Perceived Negative Effects of Tic Management Strategies in Adults With Tic Disorders.

Behavior therapy is a well-established and empirically supported treatment for tic disorders (TDs). However, concerns have been expressed about the negative effects of behavioral interventions, such as tic worsening, tic substitution, and excessive effort. This study explored perceived negative effects of tic management strategies in adults with TDs and predictors of these experiences. Participants (N = 72) completed semi-structured interviews 11 years after receiving behavior therapy or supportive therapy in a randomized clinical trial. We examined responses to interview questions about managing tics and predictors of reported negative effects. Most participants did not experience tic worsening (84%) or tic substitution (75%) from tic management strategies. The majority felt they could manage tics while participating in their environment (87%) and did not report life interference from tic management (77%). About half (45%) felt less present when managing tics. Treatment non-responders in the original trial were more likely to report negative effects of tic management strategies. No differences in reported negative consequences were found between those who received behavior therapy versus supportive therapy, suggesting that behavior therapy specifically does not lead to such adverse effects. These findings could reduce misconceptions about behavior therapy for TDs and enhance its acceptability and utilization.

Predictors of Impairment and Self-Concept in Children and Adolescents with Persistent Tic Disorder.

This study examined predictors of, and associations between, self-concept, demographic variables, and clinical measures in fifty-eight children and adolescents with Persistent Tic Disorder (PTD; 44 males, Mage = 11.9 years, SD = 2.74). Participants completed measures that assessed self-concept, tic severity, tic-related impairment, and comorbid psychological symptoms. Results showed that generalized anxiety disorder, major depressive disorder, persistent depressive disorder, total tic severity, number and complexity of tics, and total and social tic-related impairment were associated with self-concept. Tic-related social impairment mediated the relationship between tic severity and self-concept. Exploratory analyses found that total tic severity, motor tic severity, and vocal tic severity, as well as the number, intensity, and interference of tics predicted social tic-related impairment. Results suggest that treatments to reduce the number and complexity of tics, with additional focus on navigating social interactions, may serve to decrease tic severity and impairment, and in turn, improve self-concept.

Long-term follow-up of acceptance-enhanced behavior therapy for trichotillomania.

Acceptance-enhanced behavior therapy for trichotillomania (AEBT-TTM) is effective in reducing trichotillomania (TTM) symptoms, but the durability of treatment effects remains in question. This study analyzed 6-month follow-up data from a large randomized clinical trial comparing AEBT-TTM to an active psychoeducation and supportive therapy control (PST). Adults with TTM (N=85; 92% women) received 10 sessions of AEBT-TTM or PST across 12 weeks. Independent evaluators assessed participants at baseline, post-treatment, and 6 months follow-up. For both AEBT-TTM and PST, self-reported and evaluator-rated TTM symptom severity decreased from baseline to follow-up. TTM symptoms did not worsen from post-treatment to follow-up. At follow-up, AEBT-TTM and PST did not differ in rates of treatment response, TTM diagnosis, or symptom severity. High baseline TTM symptom severity was a stronger predictor of high follow-up severity for PST than for AEBT-TTM, suggesting AEBT-TTM may be a better option for more severe TTM. Results support the efficacy of AEBT-TTM and show that treatment gains were maintained over time. Although AEBT-TTM yielded lower symptoms at post-treatment, 6-month follow-up outcomes suggest AEBT-TTM and PST may lead to similar symptom levels in the longer term. Future research should examine mechanisms that contribute to long-term gain maintenance.

The Roles of Lifetime Enacted Stigma in Tic Symptoms among Young Adults with Tourette Syndrome.

Background: Although rarely framed as enacted stigma, adults with Tourette syndrome (ATS) have long suffered from discrimination associated with their tic symptoms. Given the high stress levels of enacted stigma that ATS experience, it is expected that their tic symptoms are profoundly impacted. However, the evidence linking enacted stigma to ATS's tic symptoms remains limited. Methods: This study used a secondary data-analysis approach to reanalyze the data from the follow-up phase of a multi-centered, randomized controlled trial in which a behavioral intervention was tested for its efficacy in managing tic symptoms. This study first conducted psychometric testing on a list of 16 enacted stigma events across five life stages and identified the underlying factor structure. The Yale Global Tic Severity Scale (YGTSS) was used to assess severity and impairment of current tic symptoms, whereas the Clinical Global Impression of Severity scale (CGI) was used to obtain the gestalt of clinical judgment on tic severity. A series of multivariate linear models were then fitted to test the relationships between different types of lifetime enacted stigma and current tic symptoms. Results: The analytic sample included 73 young ATS (average age of 23.2 [standard deviation = 2.5] years). The factor analysis identified three types of enacted stigmas: "traumatic events," "confrontations," and "subtle mistreatments." In multivariate models, traumatic events significantly associated with YGTSS-severity, whereas subtle mistreatments provided additional explanations for CGI. Conclusions: Enacted stigma may play important roles in shaping ATS's current tics symptom severity and, therefore, should be carefully considered in future intervention development.

Caregiver Perspectives on the Health Care System for Tic Disorders: Utilization and Barriers.

OBJECTIVE: This study aimed to understand health care experiences among a sample of caregivers of children with TDs to inform future directions for improving the health care system. METHODS: We conducted a survey of caregivers of youth with TDs and used descriptive statistics and quantitative analyses to characterize the health care utilization practices of the sample. RESULTS: The majority (70%) of families first consulted their pediatrician/primary care provider, and caregivers reported receiving care in line with current best practice guidelines. However, caregivers in the current sample perceived a lack of knowledgeability on the part of their first providers, which significantly predicted more providers seen and also reported difficulty finding specialty providers (63% of the sample reported difficulty finding a treatment provider who understood tics). CONCLUSION: Results suggest that improving caregiver satisfaction with early health care experiences for their child's TD may help to relieve the burden on families and the health care system more broadly, along with continued efforts to increase the number of specialty providers available.

Behavioral Interventions for Children and Adults with Tic Disorder.

Over the past decade, behavioral interventions have become increasingly recognized and recommended as effective first-line therapies for treating individuals with tic disorders. In this article, we describe a basic theoretical and conceptual framework through which the reader can understand the application of these interventions for treating tics. The three primary behavioral interventions for tics with the strongest empirical support (habit reversal, Comprehensive Behavioral Intervention for Tics, and exposure and response prevention) are described. Research on the efficacy and effectiveness of these treatments is summarized along with a discussion of the research evaluating the delivery of these treatments in different formats and modalities. The article closes with a review of the possible mechanisms of change underlying behavioral interventions for tics and areas for future research.

The role of psychological flexibility in acceptance-enhanced behavior therapy for trichotillomania: Moderation and mediation findings.

Trichotillomania is characterized by recurrent pulling out of one's hair, leading to significant hair loss and accompanied by clinically significant distress and/or functional impairment. The current study used data from a randomized controlled trial comparing the effectiveness of acceptance-enhanced behavior therapy (AEBT) to psychoeducation plus supportive therapy (PST; active control) for trichotillomania in an adult sample. The objectives were to examine the moderating and mediating influence of trichotillomania-specific psychological flexibility in treatment for trichotillomania. Participants with lower baseline flexibility performed better in AEBT than PST in terms of greater symptom reduction and quality of life. Lower baseline flexibility also predicted higher likelihood of disorder recovery in AEBT relative to PST. In addition, relative to PST, symptom reduction in AEBT was mediated by psychological flexibility, controlling for anxiety and depression. These findings suggest that psychological flexibility is a relevant process of change in the treatment of trichotillomania. Clinical implications and directions for future research are discussed.

Clinical Characteristics of Children With Tourette Syndrome With and Without Sleep Disorder.

BACKGROUND: Sleep problems are common in children with Tourette Syndrome (TS). However, research regarding their demographic and clinical profile is limited. METHODS: We examined characteristics of 114 children aged five to 17 years with a lifetime diagnosis of TS and compared children with sleep disorder (n = 32) and without sleep disorder (n = 82). Parent report from the 2014 National Survey of the Diagnosis and Treatment of ADHD and Tourette Syndrome provided demographics and clinical information, other diagnosed disorders, medication use, TS severity, and impairment. RESULTS: More children with TS with sleep disorder were from households with lower parental education (P < 0.01) and poverty (P = 0.04); had other diagnoses (P = 0.03), including obsessive-compulsive disorder (P < 0.01), oppositional defiant disorder or conduct disorder (P < 0.01), attention-deficit/hyperactivity disorder (ADHD) (P = 0.02), and autism (P = 0.03); and had ever used TS medication (P = 0.01) than children with TS without sleep disorder. More children with TS with sleep disorder had severe TS symptoms (P <0.01), tic-related impairment (P<0.01), and severe ADHD symptoms (P < 0.01) compared with children with TS without sleep disorder. CONCLUSIONS: Findings suggest greater parent-reported impact and tic-related interference in children with TS with sleep disorder compared with TS without sleep disorder. Results underscore the importance of monitoring and intervention for TS exacerbations, other diagnosed disorders, and medication use, and consideration of socioeconomic context in sleep disorder management and prevention in children with TS.

Neurobiology of subtypes of trichotillomania and skin picking disorder.

BACKGROUND: Trichotillomania (TTM) and skin picking disorder (SPD) are common and often debilitating mental health conditions, grouped under the umbrella term of body-focused repetitive behaviors (BFRBs). Recent clinical subtyping found that there were three distinct subtypes of TTM and two of SPD. Whether these clinical subtypes map on to any unique neurobiological underpinnings, however, remains unknown. METHODS: Two hundred and fifty one adults [193 with a BFRB (85.5% [n = 165] female) and 58 healthy controls (77.6% [n = 45] female)] were recruited from the community for a multicenter between-group comparison using structural neuroimaging. Differences in whole brain structure were compared across the subtypes of BFRBs, controlling for age, sex, scanning site, and intracranial volume. RESULTS: When the subtypes of TTM were compared, low awareness hair pullers demonstrated increased cortical volume in the lateral occipital lobe relative to controls and sensory sensitive pullers. In addition, impulsive/perfectionist hair pullers showed relative decreased volume near the lingual gyrus of the inferior occipital-parietal lobe compared with controls. CONCLUSIONS: These data indicate that the anatomical substrates of particular forms of BFRBs are dissociable, which may have implications for understanding clinical presentations and treatment response.

Childhood Predictors of Long-Term Tic Severity and Tic Impairment in Tourette's Disorder.

Tics peak in late childhood and decline during adolescence. Yet, for some with Tourette's disorder, tics persist into adulthood. We evaluated childhood predictors of adult tic severity and tic impairment, and change over time. Eighty adolescents/adults were evaluated 11 years following a randomized-controlled trial of behavior therapy. An independent evaluator rated tic severity and tic impairment at baseline, posttreatment, and long-term follow-up. At baseline, parents completed demographics/medical history, and youth tic, internalizing, and externalizing symptom ratings. Youth rated premonitory urge severity and family functioning. After controlling for prior tic treatment effects, female sex and higher tic severity predicted higher tic severity in adulthood; and female sex, no stimulant medication use, higher tic severity, and poorer family functioning predicted higher tic impairment. Higher tic severity and premonitory urge severity predicted smaller reductions in tic severity, whereas higher externalizing symptoms predicted greater reduction in tic severity. Female sex predicted smaller reduction in tic impairment, and externalizing symptoms predicted greater reduction in tic impairment. Female sex and childhood tic severity are important predictors of tic severity and tic impairment in adulthood. Family functioning, premonitory urge severity, and tic severity are important modifiable targets for early or targeted intervention to improve long-term outcomes.

Clinical Characteristics of Youth with Trichotillomania (Hair-Pulling Disorder) and Excoriation (Skin-Picking) Disorder.

Body-focused repetitive disorders (BFRBDs) are understudied in youth and understanding of their underlying mechanisms is limited. This study evaluated BFRBD clinical characteristics, and two factors commonly implicated in their maintenance - emotion regulation and impulsivity - in 53 youth aged 11 to 17 years: 33 with BFRBDs and 20 controls. Evaluators administered psychiatric diagnostic interviews. Participants rated BFRBD severity, negative affect, quality of life, family functioning, emotion regulation, distress tolerance, and impulsivity. Youth with BFRBDs showed poorer distress tolerance and quality of life, and higher impulsivity and negative affect than controls, with no differences in family impairment. BFRBD distress/impairment, but not BFRBD severity, correlated with anxiety and depression, and poorer distress tolerance. Findings suggest youth with BFRBDs show clinical patterns aligning with prior research; highlight the role of distress tolerance in child BFRBDs; and suggest the utility of acceptance and mindfulness-based therapies for unpleasant emotions in BFRBDs. Continued research should evaluate factors underlying BFRBDs in youth.

Acceptance-enhanced behavior therapy for trichotillomania in adults: A randomized clinical trial.

Given the limited treatment options for trichotillomania (TTM), or Hair Pulling Disorder, this large randomized clinical trial evaluated the efficacy of acceptance-enhanced behavior therapy for TTM (AEBT-TTM) in reducing TTM severity relative to psychoeducation and supportive therapy (PST). Eighty-five adults (78 women) with TTM received 10 sessions (over 12 weeks) of either AEBT-TTM or PST. Independent evaluators masked to treatment assignment assessed participants at baseline (week 0), midpoint (week 6), and endpoint (week 12). Consistent with a priori hypotheses, 64% of the adults treated with AEBT-TTM were classified as clinical responders at post-treatment relative to 38% treated with PST. Clinical responders were identified by a score of 1 or 2 on the Clinical Global Impressions-Improvement (CGI-I) scale. Relative to the PST group, the AEBT-TTM group demonstrated significantly greater pre-to post-treatment reductions on the self-report Massachusetts General Hospital-Hairpulling Scale (MGH-HS) and the evaluator-rated National Institute of Mental Health Trichotillomania Severity Scale (NIMH-TSS). There were no significant post-treatment group differences on the Clinical Global Impressions-Severity (CGI-S) scale, or rate of TTM diagnoses. Results suggest AEBT-TTM provides greater treatment benefit than PST. Future research should continue to investigate AEBT-TTM along with mediators and moderators of its efficacy.

Open-case series of a remote administration and group setting comprehensive behavioral intervention for tics (RG-CBIT): A pilot trial.

Purpose: The comprehensive behavioral intervention for tics (CBIT) is the first-line psychotherapeutic treatment for individuals with tic disorders. However, most patients with tic disorders do not have access to CBIT due to different factors including lack of trained therapists, treatment cost, and travel distance. Such barriers are more prominent in non-English speaking countries. Therefore, the current study assessed the preliminary efficacy, feasibility, and acceptability of remotely administered group CBIT (RG-CBIT) in Japan. Methods: This was an open-case series that adopted the AB design. Three Japanese children aged between 6 and 13 years who were diagnosed with TS were recruited. RG-CBIT was developed based on the published CBIT manual. Videoconference application, slide presentation software, and cloud learning platform were used as appropriate. Results: The Yale Global Tic Severity Scale scores of all participants decreased from baseline to post-treatment. That is, the score reduced by an average of 7.0. Regarding feasibility and acceptability, the attendance rate of participants was 100%, and the process measurement items had favorable scores. Conclusions: RG-CBIT had satisfactory efficacy, feasibility, and acceptability. Hence, it could mitigate the barriers for treatment access.

Urge intolerance predicts tic severity and impairment among adults with Tourette syndrome and chronic tic disorders.

Background: Individuals with Tourette Syndrome and Persistent Tic Disorders (collectively TS) often experience premonitory urges-aversive physical sensations that precede tics and are temporarily relieved by tic expression. The relationship between tics and premonitory urges plays a key role in the neurobehavioral treatment model of TS, which underlies first-line treatments such as the Comprehensive Behavioral Intervention for Tics (CBIT). Despite the efficacy of CBIT and related behavioral therapies, less than 40% of adults with TS respond to these treatments. Further examination of the relationship between premonitory urges, tic severity, and tic impairment can provide new insights into therapeutic targets to optimize behavioral treatment outcomes. This study examined whether urge intolerance-difficulty tolerating premonitory urges-predicted tic severity and tic-related impairment among adults with TS. Methods: Participants were 80 adults with TS. Assessments characterized premonitory urge, distress tolerance, tic severity, and tic impairment. We used structural equation modeling (SEM) to examine the construct of urge intolerance-comprised of premonitory urge ratings and distress tolerance ratings. We first evaluated a measurement model of urge intolerance through bifactor modeling, including tests of the incremental value of subfactors that reflect premonitory urge severity and distress tolerance within the model. We then evaluated a structural model where we predicted clinician-rated tic severity and tic impairment by the latent variable of urge intolerance established in our measurement model. Results: Analyses supported a bifactor measurement model of urge intolerance among adults with TS. Consistent with theoretical models, higher levels of urge intolerance predicted greater levels of clinician-rated tic severity and tic impairment. Conclusion: This investigation supports the construct of urge intolerance among adults with TS and distinguishes it from subcomponents of urge severity and distress tolerance. Given its predictive relationship with tic severity and tic impairment, urge intolerance represents a promising treatment target to improve therapeutic outcomes in adults with TS.

Pain perception and physiological correlates in body-focused repetitive behavior disorders.

BACKGROUND: Behaviors typical of body-focused repetitive behavior disorders such as trichotillomania (TTM) and skin-picking disorder (SPD) are often associated with pleasure or relief, and with little or no physical pain, suggesting aberrant pain perception. Conclusive evidence about pain perception and correlates in these conditions is, however, lacking. METHODS: A multisite international study examined pain perception and its physiological correlates in adults with TTM (n = 31), SPD (n = 24), and healthy controls (HCs; n = 26). The cold pressor test was administered, and measurements of pain perception and cardiovascular parameters were taken every 15 seconds. Pain perception, latency to pain tolerance, cardiovascular parameters and associations with illness severity, and comorbid depression, as well as interaction effects (group × time interval), were investigated across groups. RESULTS: There were no group differences in pain ratings over time (P = .8) or latency to pain tolerance (P = .8). Illness severity was not associated with pain ratings (all P > .05). In terms of diastolic blood pressure (DBP), the main effect of group was statistically significant (P = .01), with post hoc analyses indicating higher mean DBP in TTM (95% confidence intervals [CI], 84.0-93.5) compared to SPD (95% CI, 73.5-84.2; P = .01), and HCs (95% CI, 75.6-86.0; P = .03). Pain perception did not differ between those with and those without depression (TTM: P = .2, SPD: P = .4). CONCLUSION: The study findings were mostly negative suggesting that general pain perception aberration is not involved in TTM and SPD. Other underlying drivers of hair-pulling and skin-picking behavior (eg, abnormal reward processing) should be investigated.

Cognitive control processes in behavior therapy for youth with Tourette's disorder.

BACKGROUND: Cognitive control processes are implicated in the behavioral treatment of Tourette's disorder (TD). However, the influence of these processes on treatment outcomes has received minimal attention. This study examined whether cognitive control processes and/or tic suppression predicted reductions in tic severity and treatment response to behavior therapy. METHOD: Fifty-three youth with TD or a pervasive tic disorder participated in a randomized wait list-controlled trial of behavior therapy. Following a baseline assessment to evaluate psychiatric diagnoses, tic severity, and cognitive control processes (e.g., response selection, inhibition, and suppression), youth were randomly assigned to receive eight sessions of behavior therapy (n = 23) or a wait list of equal duration (n = 28). Youth receiving immediate treatment completed a post-treatment assessment to determine improvement in tic severity. Meanwhile, youth in the wait list condition completed another assessment to re-evaluate tic severity and cognitive control processes, and subsequently received 8 sessions of behavior therapy followed by a post-treatment assessment to determine improvement. RESULTS: A multiple linear regression model found that pretreatment inhibition/switching on the Delis-Kaplan Executive Function System Color-Word Interference Test predicted reductions in tic severity after behavior therapy (ß = -.36, t = -2.35, p = .025, ƞ2 = .15). However, other cognitive control processes and tic suppression did not predict treatment response and/or reductions in tic severity. Small nonsignificant effects were observed in cognitive control processes after behavior therapy. CONCLUSION: Cognitive control processes may influence tic severity reductions in behavior therapy. Notably, even when other cognitive control processes are impaired and youth are initially unable to voluntarily suppress their tics, youth with TD can still benefit from behavior therapy. Findings offer implications for clinical practice and research for TD.