Skin picking and trichotillomania in adults with obsessive-compulsive disorder

The global assessment of OCD

Obsessive Compulsive Disorder (OCD) is a common mental disorder that often causes great sufferance, with substantial impairment in social functioning and quality of life and affects family and significant relationships. Notwithstanding its severity, OCD is often not adequately diagnosed, or it is diagnosed with delay, leading often to a long latency between onset of the OCD symptoms and the start of adequate treatments. Several factors contribute to the complexity of OCD's clinical picture: early age of onset, chronic course, heterogeneity of symptoms, high rate of comorbidity with other psychiatric disorders, slow or partial response to therapy. Therefore, it is of primary importance for clinicians involved in diagnosing OCD, to assess all aspects of the disorder. This narrative review focuses on the global assessment of OCD, highlighting crucial areas to explore, pointing out the clinical features which are relevant for the treatment of the disorder, and giving an overview of the psychometric tools that can be useful during the screening procedure.

Body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms in a large sample of adolescents

Few studies have investigated body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms in adolescents and how they relate to mental health, quality of life, suicide attempts, and non-suicidal self-harm. We used a quota sampling procedure and contacted 100 secondary centres in the Southeast of Spain, of which 34 participated in the study. A sample of 5,345 adolescents (12–18 years) completed dimensional measures of body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms. The proportion of adolescents with clinically significant symptoms within each symptom type was estimated and associations with other indicators of mental health examined. Clinically significant body-dysmorphic symptoms were reported by 3.7%, hoarding by 0.9%, hair-pulling by 0.7%, and skin-picking by 1.8%. Body-dysmorphic symptoms were more common in girls and in those over 14 years of age. Body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms were moderately to strongly associated with obsessive-compulsive symptoms, internalizing symptoms, externalizing symptoms, and poor quality of life. Those with significant body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms were much more likely to have attempted suicide and engaged in non-suicidal self-harm during the last twelve months than those without such symptoms. Body-dysmorphic symptoms showed the strongest associations with internalizing symptoms and poor quality of life. Limitations are the sole use of self-report and a sample from only two regions in Spain, but findings suggest that body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms are common and impairing during adolescence.

Suicidality in patients with obsessive-compulsive and related disorders (OCRDs): A meta-analysis

INTRODUCTION

Previous meta-analyses showed that OCD is associated with a substantial risk of suicidal behaviours. Conclusive rates of suicidal ideation (current and lifetime) and suicide attempts based on pooled prevalence rates have not so far been calculated using meta-analysis for the other DSM-5 Obsessive-Compulsive and Related Disorders (OCRDs).

OBJECTIVES

This meta-analysis aims to separately calculate the pooled prevalence rates of lifetime suicide attempts and current or lifetime suicidal ideation in BDD, Hoarding Disorder (HD), Skin Picking Disorder (SPD) and Trichotillomania (TTM) and to identify factors associated with increased suicide rates.

METHODS

Our protocol was pre-registered with PROSPERO (CRD42020164395). A systematic review and meta-analysis following PRISMA reporting guidelines was performed by searching in PubMed/Medline, PsycINFO, Web of Science and CINAHL databases from the date of the first available article to April 20th, 2020. Stata version 15 was used for the statistical analysis. Given the small number of studies in TTM and SPD, the two grooming disorders were grouped together. Meta-analyses of proportions based on random effects (Der-Simonian and Laird method) were used to derive the pooled estimates.

RESULTS

Thirty-eigth studies (N = 4559 participants) were included: 23 for BDD, 8 for HD, 7 for Grooming Disorders. For BDD, the pooled prevalence of lifetime suicide attempts, current and lifetime suicidal ideation was, respectively 35.2% (CI:23.4-47.8), 37.2% (CI:23.8-51.6) and 66.1% (CI:53.5-77.7). For HD, the pooled prevalence of lifetime suicide attempts, current and lifetime suicidal ideation was 24.1% (CI:12.8-37.6), 18.4% (CI:10.2-28.3) and 38.3% (CI:35.0-41.6), respectively. For Grooming Disorders, the pooled prevalence of lifetime suicide attempts and current suicidal ideation were 13.3% (CI:5.9-22.8) and 40.4% (CI:35.7-45.3), respectively (no data available for lifetime suicidal ideation).

CONCLUSIONS

The OCRDs as a group are associated with relatively high rates of suicidal behaviour. Through indirect comparisons, we infer that BDD has the greatest risk. Comorbid substance abuse, possibly reflecting poor underlying impulse control, is associated with higher rates of suicidal behaviour in BDD. Our data emphasize the need for clinicians to consider the risk of suicidal behaviour in the management of patients presenting with all forms of OCRDs.

Specialty knowledge and competency standards for pharmacotherapy for adult obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) affects approximately one person in 40 and causes substantial suffering. Evidence-based treatments can benefit many; however, optimal treatment can be difficult to access. Diagnosis is frequently delayed, and pharmacological and psychotherapeutic interventions often fail to follow evidence-based guidelines. To ameliorate this distressing situation, the International OCD Accreditation Task Force of the Canadian Institute for Obsessive-Compulsive Disorders has developed knowledge and competency standards for specialized treatments for OCD through the lifespan. These are foundational to evidence-based practice and will form the basis for upcoming ATF development of certification/accreditation programs. Here, we present specialty standards for the pharmacological treatment of adult OCD. We emphasize the importance of integrating pharmacotherapy with clear diagnosis, appreciation of complicating factors, and evidence-based cognitive behavioral therapy. Clear evidence exists to inform first- and second-line pharmacological treatments. In disease refractory to these initial efforts, multiple strategies have been investigated, but the evidence is more equivocal. These standards summarize this limited evidence to give the specialist practitioner a solid basis on which to make difficult decisions in complex cases. It is hoped that further research will lead to development of a clear, multi-step treatment algorithm to support each step in clinical decision-making.

Sensory symptoms in body-focused repetitive behaviors, restless legs syndrome, and Tourette syndrome: An overlap?

Tourette syndrome (TS) is a neurodevelopmental condition characterized by multiple tics. Sensory symptoms play a key role in the clinical phenomenology and pathophysiology of TS, as most patients report premonitory urges driving tic expression. Interestingly, sensory symptoms have also been reported in other conditions characterized by repeated behaviors. This review explores the nature of sensory symptoms reported by patients with body focused repetitive behaviors (BFRBs, especially trichotillomania and skin picking disorder) and restless legs syndrome (RLS) in comparison to TS. A sense of mounting inner tension and reinforcement mechanisms driven by gratification and relief on expression of the tic or repetitive behavior appear to be implicated across all conditions. Subjective urges can be temporarily suppressed by patients with TS and selected BFRBs, whereas patients with RLS tend to report dysesthesia more frequently than a suppressible urge to move. The observed similarities in the phenomenology of sensory symptoms across these conditions raise the possibility of a comparable underlying pathophysiology. Preliminary findings suggest an overlap of neural pathways encompassing the insula, basal ganglia (putamen), and posterior cingulate cortex.

Reduced anterior cingulate glutamate of comorbid skin-picking disorder in adults with obsessive-compulsive disorder

BACKGROUND

Obsessive Compulsive Disorder (OCD) is characterized by hyperactivity in a network of forebrain structures, including the anterior cingulate cortex (ACC). Convergent evidence suggests that glutamatergic dysfunction may contribute to the disorder. Skin picking disorder (SPD) was listed as one of the obsessive-compulsive and related disorders, which is often comorbid with OCD and share overlapping phenomenology and pathophysiology. However, potential confounding effects between the two diagnostic effects on neurotransmitter levels remain largely unexamined.

METHODS

We examined the pregenual anterior cingulate cortex (pACC) glutamate and other neurochemicals in 62 subjects using a single-voxel acquisition 1H MRS at 3Tesla; of these, 47 subjects yielded usable measurements of both glutamate and glutamine and were included in the analysis (17 medicated with OCD alone, 13 medicated with comorbid OCD + SPD, 17 healthy control).

RESULTS

OCD with comorbid SPD showed significantly lower pACC glutamate than in patients without SPD (p = 0.001) or control subjects (p = 0.035). OCD without SPD subjects showed pACC glutamate levels indistinguishable from controls (p = 0.501). In the OCD with SPD subjects, glutamate was correlated with Y-BOCS total score in female patients (n = 9, r = 0.69, p = 0.041).

LIMITATIONS

The main limitation of the study was the cross-sectional data. Our patients were on SSRI medication which may have modified the effect of SPD and OCD interaction on glutamate activity.

CONCLUSION

Our results suggest that alterations of the glutamatergic system may play an important role in the pathophysiology of a subgroup of OCD and reduced pACC glutamate may be a biomarker of a distinct subset of OCD patients.

Self-reported and neurocognitive impulsivity in obsessive-compulsive disorder

BACKGROUND

Although a behavioural addiction model of obsessive-compulsive disorder (OCD) has been proposed, it is still unclear if and how self-report and neurocognitive measures of impulsivity (such as risk-taking-, reflection- and motor-impulsivities) are impaired and/or inter-related in this particular clinical population.

METHODS

Seventeen OCD patients and 17 age-, gender-, education- and IQ-matched controls completed the Barratt Impulsivity Scale, the Obsessive-Compulsive Inventory-Revised, and the Beck Depression Inventory and were evaluated with the Yale-Brown Obsessive-Compulsive Scale and three computerized paradigms including reward (the Cambridge Gambling Task), reflection (the Information Sampling Task) and motor impulsivity (Stop Signal Task).

RESULTS

Despite not differing from healthy controls in any neurocognitive impulsivity domain, OCD patients demonstrated increased impulsivity in a self-report measure (particularly attentional impulsivity). Further, attentional impulsivity was predicted by severity of obsessive-compulsive symptoms.

CONCLUSIONS

Our findings suggest that OCD is characterized by a subjective (rather than objective) impulsivity; in addition, self-reported impulsivity was largely determined by severity of OCD symptoms.

Trichotillomania is more related to Tourette disorder than to obsessive-compulsive disorder

OBJECTIVE

Trichotillomania (TTM) is characterized by the pulling out of one's hair. TTM was classified as an impulse control disorder in DSM-IV, but is now classified in the obsessive-compulsive related disorders section of DSM-5. Classification for TTM remains an open question, especially considering its impact on treatment of the disorder. In this review, we questioned the relation of TTM to tic disorder and obsessive-compulsive disorder (OCD).

METHOD

We reviewed relevant MEDLINE-indexed articles on clinical, neuropsychological, neurobiological, and therapeutic aspects of trichotillomania, OCD, and tic disorders.

RESULTS

Our review found a closer relationship between TTM and tic disorder from neurobiological (especially imaging) and therapeutic standpoints.

CONCLUSION

We sought to challenge the DSM-5 classification of TTM and to compare TTM with both OCD and tic disorder. Some discrepancies between TTM and tic disorders notwithstanding, several arguments are in favor of a closer relationship between these two disorders than between TTM and OCD, especially when considering implications for therapy. This consideration is essential for patients.

Disgust, shame and the psychosocial impact of skin picking: Evidence from an online support forum

This article examines the accounts of individuals who problematically pick their skin and explores their subjective experiences. In total, 100 problem disclosure statements were taken from posts made to a publicly accessible online skin picking support forum. These posts were systematically analysed using thematic analysis. Themes of disgust, shame and psychosocial avoidance dominated the analysis and appeared central to the experience of skin picking. Skin picking was shown to be a heterogeneous experience with a complex emotional profile. We argue that disgust, shame and related avoidance behaviour should be considered when conceptualising skin picking and considering treatment interventions.

A comparison of symptom dimensions for obsessive compulsive disorder and obsessive compulsive-related disorders

Objective

In this study, it is aimed to determine obsessive compulsive-related disorders (OCRDs) comorbidity among the patients with obsessive compulsive disorder (OCD) and compare patients with OCD with or without comorbid OCRDs in terms of the severity of their OCD symptoms, symptom dimensions, and comorbidity with other axis I disorders.

Methods

The study included 90 patients diagnosed as having OCD according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for OCRDs were used to determine the presence of OCRDs. In order to determine the symptom dimensions and severity of these individuals’ OCD symptoms, we administered the Dimensional Obsessive Compulsive Scale (DOCS) and The Yale-Brown Obsessive Compulsive Scale (Y-BOCS).

Results

In our study, 20% of the patients with OCD simultaneously met the criteria for at least one OCRD, we also found that a significantly greater proportion of this group were men. None of the mentioned disorders was associated with any symptom dimensions we evaluated using DOCS. In addition, no differences were found in the severity of OCD symptoms and comorbid axis I disorders between the group with comorbid OCRDs and the group without comorbid OCRDs.

Discussion

There was no significant relationship between the symptom dimensions of OCD and OCRDs. It is found that OCRD comorbidity does not increase the severity of OCD symptoms and the prevalence of an axis I diagnosis.

Prevalence and predictors of hair pulling disorder and excoriation disorder in Tourette syndrome

Trichotillomania/hair pulling disorder (HPD) and excoriation/skin picking disorder (SPD) are childhood-onset, body-focused repetitive behaviors that are thought to share genetic susceptibility and underlying pathophysiology with obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). We sought to determine the prevalence of DSM-5 HPD and SPD in TS patients, and to identify clinical factors most associated with their co-morbidity with TS. Participants included 811 TS patients recruited from TS specialty clinics for a multi-center genetic study. Patients were assessed using standardized, validated semi-structured interviews. HPD and SPD diagnoses were determined using a validated self-report questionnaire. HPD/SPD prevalence rates were calculated, and clinical predictors were evaluated using regression modeling. 3.8 and 13.0% of TS patients met DSM-5 criteria for HPD and SPD, respectively. In univariable analyses, female sex, OCD, and both tic and obsessive-compulsive symptom severity were among those associated with HPD and/or SPD. In multivariable analyses, only lifetime worst-ever motor tic severity remained significantly associated with HPD. Female sex, co-occurring OCD, ADHD, and motor tic severity remained independently associated with SPD. This is the first study to examine HPD and SPD prevalence in a TS sample using semi-structured diagnostic instruments. The prevalence of HPD and SPD in TS patients, and their association with increased tic severity and co-occurring OCD, suggests that clinicians should screen children with TS and related disorders for HPD/SPD, particularly in females and in those with co-occurring OCD. This study also helps set a foundation for subsequent research regarding HPD/SPD risk factors, pathophysiology, and treatment models.

Presidential Address: Are the Obsessive-Compulsive Related Disorders Related to Obsessive-Compulsive Disorder? A Critical Look at DSM-5's New Category

The 5^th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) includes a new class of obsessive-compulsive and related disorders (OCRDs) that includes obsessive-compulsive disorder (OCD) and a handful of other putatively related conditions. Although this new category promises to raise awareness of underrecognized and understudied problems, the empirical validity and practical utility of this new DSM category is questionable. This article critically examines the arguments underlying the new OCRD class, illuminates a number of problems with this class, and then discusses implications for clinicians and researchers.

Trichotillomania

Trichotillomania, characterized by the repetitive pulling out of one’s own hair leading to hair loss and functional impairment, has been documented in the medical literature since the 19^th century, but has received scant research attention. Community prevalence studies suggest that trichotillomania is a common disorder with point prevalence estimate of 0.5% to 2.0%. Although recently grouped with OCD in the DSM-5, clinicians need to be aware that trichotillomania and OCD may have less in common than originally thought. In fact, approaches to treating trichotillomania, which include habit reversal therapy and medication (n-acetyl cysteine or olanzapine), are quite different from those used to treat OCD; and some first-line treatments used for OCD appear ineffective for trichotillomania. Based on our clinical experience and research findings, the article recommends several management approaches to trichotillomania.

Abnormal brain activation in excoriation (skin-picking) disorder: evidence from an executive planning fMRI study

BACKGROUND

Excoriation (skin-picking) disorder (SPD) is a relatively common psychiatric condition whose neurobiological basis is unknown.

AIMS

To probe the function of fronto-striatal circuitry in SPD.

METHOD

Eighteen participants with SPD and 15 matched healthy controls undertook an executive planning task (Tower of London) during functional magnetic resonance imaging (fMRI). Activation during planning was compared between groups using region of interest and whole-brain permutation cluster approaches.

RESULTS

The SPD group exhibited significant functional underactivation in a cluster encompassing bilateral dorsal striatum (maximal in right caudate), bilateral anterior cingulate and right medial frontal regions. These abnormalities were, for the most part, outside the dorsal planning network typically activated by executive planning tasks.

CONCLUSIONS

Abnormalities of neural regions involved in habit formation, action monitoring and inhibition appear involved in the pathophysiology of SPD. Implications exist for understanding the basis of excessive grooming and the relationship of SPD with putative obsessive-compulsive spectrum disorders.

Impulsivity in body-focused repetitive behavior disorders: Disparate clinical associations between three distinct measures

OBJECTIVE

Research on trichotillomania (TTM) and excoriation (skin-picking) disorder (SPD) has suggested that impulsivity may be an important cognitive underpinning of the behavior, but many studies have produced mixed results. This analysis assessed impulsivity in TTM and SPD using three measures: the Barratt Impulsiveness Scale (BIS), the Eysenck Impulsiveness Questionnaire (EIQ), and the Stop-Signal Task (SST).

METHODS

Two hundred and eighty three subjects with TTM or SPD completed measurement of impulsivity as a part of participation in several research studies. Subjects scoring one standard deviation above or below measure means were included in the analysis for that scale (SST: N = 45; EIQ: N = 32; BIS: N = 34). High and low impulsive groups were compared within measures on demographic, clinical, and behavioral variables.

RESULTS

Results differed by group, with domains of the BIS showing associations with clinical severity, quality of life, and anxiety, and the SST showing several differences, but not clinical severity. The EIQ domains showed no significant differences. No groups differed demographically.

CONCLUSIONS

These results suggest that the EIQ, BIS, and SST assess distinct characteristics. Notably, only the attentional domain from the BIS predicted higher severity scores. Future research needs to clarify the ideal utility for these scales as they relate to TTM and SPD. Key points The BIS, EIQ, and SST domains are associated with distinct clinical differences between high and low impulsivity groups. Only the subjects in the high attentional impulsivity domain of the BIS showed significantly elevated symptom severity. The high and low impulsivity groups within the EIQ domains did not show any significant differences. These disparate associations may indicate the need for better subtyping of impulsivity, as different measures of specific domains appear to show associations with distinct features.

The correlates of obsessive-compulsive, schizotypal, and borderline personality disorders in obsessive-compulsive disorder

We assessed correlates of obsessive-compulsive (OCPD), schizotypal (SPD) and borderline (BPD) personality disorders in 110 obsessive-compulsive disorder (OCD) patients. We found OCD patients with OCPD (20.9%) to exhibit higher rates of hoarding and bipolar disorders, increased severity of hoarding and symmetry, lower prevalence of unacceptable thoughts involving sex and religion and less non-planning impulsivity. Conversely, OCD patients with SPD (13.6%) displayed more frequently bipolar disorder, increased severity of depression and OCD neutralization, greater prevalence of "low-order" behaviors (i.e., touching), lower low-planning impulsivity and greater "behavioral" compulsivity. Finally, in exploratory analyses, OCD patients with BPD (21.8%) exhibited lower education, higher rates of several comorbid psychiatric disorders, greater frequency of compulsions involving interpersonal domains (e.g. reassurance seeking), increased severity of depression, anxiety and OCD dimensions other than symmetry and hoarding, more motor and non-planning impulsivity, and greater "cognitive" compulsivity. These findings highlight the importance of assessing personality disorders in OCD samples.

Body-focused repetitive behavior disorders in ICD-11

This article addresses the question of how body-focused repetitive behavior disorders (e.g., trichotillomania and skin-picking disorder) should be characterized in ICD-11. The article reviews the historical nosology of the two disorders and the current approaches in DSM-5 and ICD-10. Although data are limited and mixed regarding the optimal relationship between body-focused repetitive behavior disorders and nosological categories, these conditions should be included within the obsessive-compulsive and related disorders category, as this is how most clinicians see these behaviors, and as this may optimize clinical utility. The descriptions of these disorders should largely mirror those in DSM-5, given the evidence from recent field surveys. The recommendations regarding ICD-11 and body-focused repetitive behavior disorders should promote the global identification and treatment of these conditions in primary care settings.

Excoriation (skin-picking) disorder in adults: a cross-cultural survey of Israeli Jewish and Arab samples

OBJECTIVE

We sought to estimate the lifetime prevalence of Excoriation (Skin-Picking) Disorder (SPD) in the Israeli adult population as a whole and compare SPD prevalence in the Jewish and Arab communities. We also explored demographic, medical and psychological correlates of SPD diagnosis.

METHODS

Questionnaires and scales screening for SPD, and assessing the severity of perceived stress, depression, obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), alcohol use, illicit drug use, and medical disorders were completed in a sample of 2145 adults attending medical settings.

RESULTS

The lifetime prevalence of SPD was 5.4% in the total sample; it did not differ between genders or within Jewish and Arab subsamples. Severity of depression (p<0.001), OCD (p<0.001) and perceived stress (p=<0.001) were greater in the SPD positive sample. Similarly, diagnoses of BDD (p=0.02) and generalized anxiety (p=0.03) were significantly more common in the SPD-positive respondents. Alcohol use and illicit substance use were significantly more common among SPD positive respondents in the total sample (both p's=0.01) and the Jewish subsample (p=0.03 and p=0.02, respectively). Hypothyroidism was more prevalent in the SPD-positive Jewish subsample (p=0.02). In the total sample, diabetes mellitus was more common in women than in men (p=0.04).

CONCLUSION

Lifetime SPD appears to be relatively common in Israeli adults and associated with other mental disorders. Differences in the self-reported medical and psychiatric comorbidities between the Jewish and Arab subsamples suggest the possibility of cross-cultural variation in the correlates of this disorder.

Excoriation (skin picking) disorder in Israeli University students: prevalence and associated mental health correlates

OBJECTIVE

The purpose of the study was to examine the prevalence of excoriation (skin picking) disorder (SPD) and associated physical and mental health correlates in a sample of Israeli university students.

METHODS

Five thousand Israeli students were given questionnaires screening for SPD, depression, obsessive-compulsive disorder, body dysmorphic disorder and disruptive, impulse control and conduct disorders. A total of 2176 participants (43.6%) responded and were included in the analysis. Mean age was 25.1 ± 4.8 (range 17-60) years, and 64.3% were female.

RESULTS

The proportion of students who were screened positive for SPD was 3.03%, with a nearly equal gender distribution (3.0% in females and 3.1% in males). There was a trend toward significantly higher rates of psychiatric problems such as generalized anxiety, compulsive sexual behavior and eating disorders in these students. Within the group of students screening positive for SPD, alcohol intake was higher in male students, while female students perceived themselves as less attractive. No association was found between depression and SPD. A high prevalence rate of skin picking was found within first-degree family members of the participants screening positive for SPD.

CONCLUSIONS

Clinicians and public health officials within university settings should screen for SPD as it is common and associated with psychosocial dysfunction.

A family study of trichotillomania and chronic hair pulling

Little is known about the etiology of hair pulling (HP) and its relationship to other obsessive compulsive (OC) spectrum disorders. In a large-sample family study, we examined the familial aggregation of HP and co-transmission of obsessive compulsive disorder (OCD) and skin picking (SP). Our sample consisted of 110 proband cases with HP and 48 controls without HP, plus 128 first-degree case relatives and 50 first-degree control relatives. Case versus control relatives had higher recurrence risk estimates for both HP and OCD but not SP. The finding that HP is familial is consistent with the only existing twin study. Additional analyses suggest that there may be a familial subtype of HP with comorbid OCD. Those adult proband cases with HP + OCD had more anxiety and depression than cases without OCD. Probands with HP + OCD also had earlier onset of OCD. Identification of an HP subtype with comorbid OCD may have significant theoretical and treatment implications. The data did not provide evidence for an etiologic relationship between HP and SP. Replication of these findings in future studies with larger cohorts of case and control relatives is warranted.

Common and rare alleles of the serotonin transporter gene, SLC6A4, associated with Tourette's disorder

To evaluate the hypothesis that functionally over-expressing alleles of the serotonin transporter (SERT) gene (solute carrier family 6, member 4, SLC6A4) are present in Tourette's disorder (TD), just as we previously observed in obsessive compulsive disorder (OCD), we evaluated TD probands (N = 151) and controls (N = 858). We genotyped the refined SERT-linked polymorphic region 5-HTTLPR/rs25531 and the associated rs25532 variant in the SLC6A4 promoter plus the rare coding variant SERT isoleucine-to-valine at position 425 (I425V). The higher expressing 5-HTTLPR/rs25531 LA allele was more prevalent in TD probands than in controls (χ(2)  = 5.75; P = 0.017; odds ratio [OR], 1.35); and, in a secondary analysis, surprisingly, it was significantly more frequent in probands who had TD alone than in those who had TD plus OCD (Fisher's exact test; P = 0.0006; OR, 2.29). Likewise, the higher expressing LAC haplotype (5-HTTLPR/rs25531/rs25532) was more frequent in TD probands than in controls (P = 0.024; OR, 1.33) and also in the TD alone group versus the TD plus OCD group (P = 0.0013; OR, 2.14). Furthermore, the rare gain-of-function SERT I425V variant was observed in 3 male siblings with TD and/or OCD and in their father. Thus, the cumulative count of SERT I425V becomes 1.57% in OCD/TD spectrum conditions versus 0.15% in controls, with a recalculated, family-adjusted significance of χ(2) = 15.03 (P < 0.0001; OR, 9.0; total worldwide genotyped, 2914). This report provides a unique combination of common and rare variants in one gene in TD, all of which are associated with SERT gain of function. Thus, altered SERT activity represents a potential contributor to serotonergic abnormalities in TD. The present results call for replication in a similarly intensively evaluated sample. © 2013 Movement Disorder Society.