Investigating the effects of tic suppression on premonitory urge ratings in children and adolescents with Tourette's syndrome

Tics represent a complex class of behaviors that have a neurobiological origin and are influenced by factors both internal and external to the individual. One factor that has gained recent attention is the premonitory urge. Contemporary behavioral models suggest that some tics are preceded by aversive somatic urges that increase in severity when tics are suppressed and are attenuated by performance of the tic. It has been proposed that the removal of premonitory urges may strengthen or maintain tics via negative reinforcement. This investigation is the first to empirically evaluate the effect of tic suppression on the premonitory urge phenomenon. Five children and adolescents, ages 8–17 years, participated in the study. Using an ABAB reversal design, tic frequency and subjective premonitory urge ratings were recorded under conditions of free-to-tic baseline (BL) and reinforced tic suppression (differential reinforcement of zero-rate behavior). Results show that four of the five children demonstrated reliable suppression. Of the four children who achieved suppression, three demonstrated a pattern in which subjective urge ratings were higher during suppression than during BL. Results provide preliminary support for the negative reinforcement view of tic function for some children.     

Time processing in children with Tourette’s syndrome

Background

Tourette syndrome (TS) is characterized by dysfunctional connectivity between prefrontal cortex and sub-cortical structures, and altered meso-cortical and/or meso-striatal dopamine release. Since time processing is also regulated by fronto-striatal circuits and modulated by dopaminergic transmission, we hypothesized that time processing is abnormal in TS.

Methods

We compared time processing abilities between nine children with TS-only (i.e. without major psychiatric comorbidities) and 10 age-matched healthy children, employing a time reproduction task in which subjects actively reproduce different temporal intervals, and a time comparison task in which subjects judge whether a test interval is longer or shorter than a reference interval. IQ, sustained and divided attention, and working memory were assessed in both groups using the Leiter International Performance Scale-Revised, and the Digit Span sub-test of the WISC-R.

Results

Children with TS-only reproduced in an overestimated fashion over-second, but not sub-second, time intervals. The precision of over-second intervals reproduction correlated with tic severity, in that the lower the tic severity, the closer the reproduction of over-second time intervals to their real duration. Time reproduction performance did not significantly correlate with IQ, attention and working memory measures in both groups. No differences between groups were documented in the time comparison task.

Conclusions

The improvement of time processing in children with TS-only seems specific for the over-second range of intervals, consistent with an enhancement in the ‘cognitively controlled’ timing system, which mainly processes longer duration intervals, and depends upon dysfunctional connectivity between the basal ganglia and the dorso-lateral prefrontal cortex. The absence of between-group differences on time comparison, moreover, suggests that TS patients manifest a selective improvement of ‘motor’ timing abilities, rather than of perceptual time abilities. Our data also support an enhancement of cognitive control processes in TS children, probably facilitated by effortful tic suppression.     

Examining the impact of distraction on tic suppression in children and adolescents with Tourette syndrome

Tourette syndrome (TS) is characterized by motor and/or vocal tics. Tics are thought to be temporarily suppressible, and it is believed that suppression requires significant attentional resources. The aim of the current study was to examine the impact of an attention-demanding distraction task on tic suppression. A secondary aim was to examine whether performance on that task decreased during concomitant periods of suppression. Nine children with TS, ages 9-15, participated in the study. An alternating treatment design was used to compare three conditions, free-to-tic baseline (BL), reinforced tic suppression (SUP) and reinforced tic suppression plus a distraction task (SUP + DIS). Tic frequencies were significantly higher during BL conditions than both SUP and SUP + DIS conditions, and tic frequencies during SUP and SUP + DIS did not differ. Accuracy on the distraction task decreased during SUP + DIS as compared to BL. Results suggest that contextual distractions may not negatively impact tic frequencies. In addition, accuracy on an attention-demanding task may be impacted if a child is simultaneously suppressing.     

Hoarding in obsessive compulsive disorder: results from a case-control study

Hoarding occurs relatively frequently in obsessive-compulsive disorder (OCD), and there is evidence that patients with hoarding symptoms have more severe OCD and are less responsive to treatment. In the present study, we investigated hoarding symptoms in 126 subjects with OCD. Nearly 30% of the subjects had hoarding symptoms; hoarding was twice as prevalent in males than females. Compared to the 90 non-hoarding subjects, the 36 hoarding individuals had an earlier age at onset of, and more severe, obsessive-compulsive symptoms. Hoarders had greater prevalences of symmetry obsessions, counting compulsions, and ordering compulsions. Hoarders also had greater prevalences of social phobia, personality disorders, and pathological grooming behaviors (skin picking, nail biting, and trichotillomania). Hoarding and tics were more frequent in first-degree relatives of hoarding than non-hoarding probands. The findings suggest that the treatment of OCD patients with hoarding symptoms may be complicated by more severe OCD and the presence of co-occurring disorders. Hoarding appears to be transmitted in some OCD families and may differentiate a clinical subgroup of OCD.     

Psychopathological Profile in Children with Chronic Tic Disorder and Co-existing ADHD: Additive Effects

The nature of the co-occurrence of chronic tic disorders (CTD) and attention deficit hyperactivity disorder (ADHD) is unclear. Especially in the field of psychopathology, the relationship of CTD and ADHD remains to be clarified. Thus, the aim of the present chart review study was to specify the contribution of CTD and/or ADHD to the psychopathological profile of the comorbid group (CTD+ADHD). The psychopathological profiles of four large groups (CTD-only (n=112), CTD+ADHD (n=82), ADHD-only (n=129), controls (n=144)) were measured by the eight subscales of the Child Behavior Checklist (CBCL) and analyzed by a 2×2 factorial design followed by contrasts. There were main effects of ADHD diagnosis on all but one subscale of the CBCL (Somatic Complaints). For CTD diagnosis, main effects were found for Attention Problems, Anxious/Depressed, Thought Problems, Social Problems and Somatic Complaints. The only interaction effect was seen for Somatic Complaints. While CTD and ADHD were both related to internalizing psychopathology of children in the CTD+ADHD group, ADHD had the largest effect on externalizing psychopathology in the comorbid group. At the level of psychopathology, an additive model for the co-occurrence of CTD and ADHD is strongly supported. In the comorbid group (CTD+ADHD), the ADHD diagnosis shows the strongest relation to externalizing psychopathology.     

Cognitive behavioral management of Tourette's syndrome and chronic tic disorder in medicated and unmedicated samples

Objective

Cognitive behavior therapy (CBT) and medication can be administered in combination in treating tic disorders but there are no studies evaluating the effectiveness of CBT with and without medication. The current study compares the efficacy of CBT in combination with medication and without medication.

Method

CBT was administered in a consecutively referred sample of 76 people diagnosed either with Gilles de la Tourette Syndrome or chronic tic disorder. The sample was divided into a medicated and a non-medicated group. Twenty three were stabilized on medication and 53 were not receiving medication. Measures administered pre- and post-CBT in both groups included: main outcome measure of Tourette Syndrome Global Scale and measures of mood.

Results

Repeated measures analysis of variance on the initial sample revealed no difference between medicated and non-medicated groups in outcome. A further analysis comparing the 23 receiving medication with 23 not receiving medication matched on baseline clinical variables also yielded no significant group differences, either in treatment outcome on main tic outcome measures or on other clinically relevant questionnaires.

Discussion

CBT for tic disorders is an effective treatment administered either in combination with medication or alone.     

The impact of a stress induction task on tic frequencies in youth with Tourette Syndrome

Tourette Syndrome (TS) is a neuropsychiatric disorder characterized by motor and vocal tics. Tic fluctuations are common and thought to be attributable in part, to contextual variables. Stress is one such variable, but its effects and mechanism of action are poorly understood. The current study measured the effects of a stress induction task on tic frequencies during periods of suppression and non-suppression of tics. Ten youth with TS between the ages of 9 and 17 were exposed to four conditions in random sequence: free-to-tic baseline (BL), reinforced tic suppression (SUP), reinforced tic suppression plus a stress induction task (SUP + STRESS), and a stress induction task alone (STRESS). Tic frequencies did not differ during STRESS and BL. Tic frequencies were greater in SUP + STRESS than SUP. Stress may impact tics through disrupting suppression efforts. Clinically, results suggest that interventions designed to improve tic inhibition in the presence of acute stressors may be beneficial.