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

Abstract

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.

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

“…57 In this same multivariable analysis, comorbid OCD was not associated with occurrence of TTM in TS patients. 57 Finally, we found that between 2.6 and 20% of TTM patients had a history of OCD, 49,53,[59][60][61][62] while 0 to 3% had a history of tic disorders. 53,60 When comparing tic comorbidity in OCD and TTM patients, five studies reported that TTM patients have the same level of tic disorders as OCD patients.…”

“…67 These studies highlight a relationship between tics and TTM, not only in an OCD context (and, possibly, in the specific context of early-onset OCD 7,54 ), but also directly in TS patients. 57 This last study helps us reach the conclusion that the TTM-tic relationship seems stronger than the TTM-OCD relationship, since OCD was not associated with occurrence of TTM in TS patients.…”

“…6 When we searched for studies on comorbid TTM in TS patients, we found that about 3.8-10% of TS patients also have TTM. 57,58 More importantly, in a multivariable analysis of TTM occurring in TS patients, one of these studies found that only Yale-Global Tic Severity Scale (YGTSS) motor score was associated with occurrence of TTM in comorbidity with TS. 57 In this same multivariable analysis, comorbid OCD was not associated with occurrence of TTM in TS patients.…”

“…57,58 More importantly, in a multivariable analysis of TTM occurring in TS patients, one of these studies found that only Yale-Global Tic Severity Scale (YGTSS) motor score was associated with occurrence of TTM in comorbidity with TS. 57 In this same multivariable analysis, comorbid OCD was not associated with occurrence of TTM in TS patients. 57 Finally, we found that between 2.6 and 20% of TTM patients had a history of OCD, 49,53,[59][60][61][62] while 0 to 3% had a history of tic disorders.…”

“…Epidemiological data showed different results concerning age of onset and course of these disorders, but suggesting a closer link between TTM and OCD, while studies of comorbidity (especially rates of TTM, OCD, and TS comorbidity among these conditions) seemed to suggest a closer link between TTM and TS. 57 It is difficult to reach a conclusion according to these epidemiological data.…”