Behavior Modification

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Negative Reinforcement and Premonitory Urges in Youth With Tourette Syndrome: An Experimental Evaluation Matthew R. Capriotti, Bryan C. Brandt, Jennifer E. Turkel, Han-Joo Lee and Douglas W. Woods Behav Modif published online 21 April 2014 DOI: 10.1177/0145445514531015 The online version of this article can be found at: http://bmo.sagepub.com/content/early/2014/04/21/0145445514531015

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BMOXXX10.1177/0145445514531015Behavior ModificationCapriotti et al.

Article

Negative Reinforcement and Premonitory Urges in Youth With Tourette Syndrome: An Experimental Evaluation

Behavior Modification 1–21 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0145445514531015 bmo.sagepub.com

Matthew R. Capriotti1, Bryan C. Brandt2, Jennifer E. Turkel1, Han-Joo Lee1, and Douglas W. Woods3

Abstract Tourette syndrome (TS) is marked by the chronic presence of motor and vocal tics that are usually accompanied by aversive sensory experiences called “premonitory urges.” Phenomenological accounts suggest that these urges occur before tics and diminish following their occurrence. This has led some to suggest that tics are negatively reinforced by removal of premonitory urges. This hypothesis has proven difficult to test experimentally, however, due in part to challenges in measuring premonitory urge strength. We tested predictions of the negative reinforcement conceptualization of premonitory urges using novel experimental tactics within the context of the “tic detector” paradigm. We compared tic rates and ratings of premonitory urge strength exhibited by youth with TS or chronic tic disorder under free-to-tic baseline (BL), reinforced tic suppression (RTS), and reinforced tic suppression with escape (RTS + E) conditions. Results were consistent with previous research and hypotheses of the present study. Participants rated

1University

of Wisconsin–Milwaukee, Milwaukee, USA of South Florida, Tampa, USA 3Texas A&M University, College Station, USA 2University

Corresponding Author: Douglas W. Woods, Department of Psychology, Texas A&M University, 4235 TAMU, College Station, TX 77843, USA. Email: [email protected]


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Behavior Modification

the strength of their premonitory urges as higher during RTS conditions than during BL conditions. Within RTS + E conditions, tic rates were higher during escape portions when the contingency supporting tic suppression was inactive than during components where the contingency was active, and ratings of urge strength were higher at the onset of break periods than at the offset. All participants engaged in some level of escape from reinforced suppression during the course of the experiment. Results of this study support the notion that tics may be negatively reinforced by removal of aversive premonitory urges. Future directions for basic and clinical research are discussed. Keywords Tourette syndrome, tic disorders, experimental psychopathology Chronic tic disorders (CTDs), including Tourette syndrome (TS), are childhood-onset neurobehavioral conditions marked by the presence of multiple motor and/or phonic tics that have been consistently present for one year or longer (American Psychiatric Association, 2013). In addition to the tics, a majority of individuals report the presence of “premonitory urges” immediately prior to ticcing. Patients describe these urges as aversive somatosensory experiences which occur prior to a tic and temporarily diminish as the tic occurs (Bliss, Cohen, & Freedman, 1980; Kane, 1994; Leckman, Walker, & Cohen, 1993; Shapiro, Shapiro, Young, & Feinberg, 1988; Woods, Piacentini, Himle, & Chang, 2005). Such descriptions of the urge have led some (e.g., Bullen & Hemsley, 1983; Evers & van de Wetering, 1994) to hypothesize that relief from premonitory urges functions as a negative reinforcer central to tic maintenance. Research using patient-report data has been consistent with this negative reinforcement hypothesis. In a survey of adolescents and adults with TS (Leckman et al., 1993), 92% reported their tics were “in response to” premonitory urges. Likewise, in another study of youth with TS (Woods et al., 2005), a large majority of participants noted that after they performed a tic, premonitory urges were reduced, at least temporarily. Researchers have also evaluated the negative reinforcement hypothesis using controlled laboratory evaluations. Himle, Woods, Conelea, Bauer, and Rice (2007) demonstrated that ratings of urge strength (made every 10 s on a Likert-type scale) were higher during periods of reinforced tic suppression (RTS) than during free-to-tic baseline (BL) conditions. This was interpreted as consistent with the negative reinforcement hypothesis, which would


Capriotti et al.

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predict that (a) blocking the performance of tics would increase the salience of the urge and (b) urge ratings would be relatively low under BL conditions, in which many tics occur and could reduce urges. However, several laboratory studies (Capriotti, Brandt, Ricketts, Espil, & Woods, 2012; Conelea, Brandt, & Woods, 2011; Specht et al., 2013; Woods, Walther, Bauer, Kemp, & Conelea, 2009) have failed to replicate this finding. Reasons for these failures to replicate are unclear, but one possible reason is that different measures were used to assess urge strength. Himle and colleagues (2007) collected ratings of urge strength every 10 s during experimental conditions, whereas two of the three other studies relied on retrospective reports collected at the end of each 5 to 10 min experimental condition. In addition, the authors of two of these studies (Conelea et al., 2011; Woods et al., 2009) reported that their data were trending toward a replication of the Himle et al. (2007) study and suspected the failure to replicate may have been due to low statistical power. On the whole, experimental evidence may be regarded as partially consistent with the negative reinforcement hypothesis, with the need for further, wellpowered replications to provide clarification. Aside from statistical power, problems exist with respect to how urges are assessed. Currently, no techniques for directly assessing momentary urge strength exist, and no robust biomarker for the phenomenon has been established. Given these barriers, a plausible alternative approach may involve operationalizing urge strength as the rate of an observable response upon which removal of the urge is contingent. Indeed, at least one previous study (Hoogduin, Verdellen, & Cath, 1997) has evaluated premonitory urges within this framework by regarding tic frequency as a proxy for urge strength. Unfortunately, this particular approach does not allow for dissociation of urge phenomena from ticcing itself. In the present study, we aimed to solve this problem using a novel experimental paradigm. This approach involved (a) inducing increased urge strength via reinforcing tic suppression, (b) including an observable behavioral response distinct from ticcing itself that would produce the opportunity to escape from premonitory urges (i.e., it would produce a brief, free-to-tic period), and (c) utilizing a response that could be standardized across groups of patients with tics. Using this novel measure along with existing measures of the urge, the present study aimed to replicate and extend previous research on the functional role of premonitory urges. We hypothesized that tic rates would be lower during periods in which reinforcement was provided contingent on the nonoccurrence of tics compared with conditions in which no programmed consequences for ticcing were in effect (Hypothesis 1). We also made a number of other predictions based on a negative reinforcement model. We predicted that average urge ratings would be higher during reinforced suppression


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conditions than during free-to-tic baseline conditions (Hypothesis 2). As an exploratory aim of the present study, we also sought to find patterns in the data that might explain inconsistency in previous findings regarding the negative reinforcement hypothesis. We predicted that tic rates would be higher during free-to-tic breaks in which the participant was allowed to temporarily terminate the reinforced suppression (also known as “escape periods”) than during preceding and subsequent periods in which suppression was reinforced (Hypothesis 3). We hypothesized that ratings of momentary urge strength would be higher at the initiation of the escape-producing response than at the end of the escape interval (Hypothesis 4), and that children who indicated the presence of premonitory urges on the Premonitory Urge for Tics Scale (PUTS; Woods et al., 2005) would engage in some level of the target escape-producing behavior (Hypothesis 5).

Method Participants Children were consecutively recruited for a separate treatment study conducted through the Tic Disorders Specialty Clinic at the University of Wisconsin–Milwaukee. The present study occurred as part of an initial visit to the clinic to determine eligibility for the larger treatment study. Inclusion criteria for participation in the present study included (a) age of 8 to 17 years, (b) positive diagnosis of TS or a CTD, (c) Yale Global Tic Severity Scale (YGTSS) total tic score ≥ 13 but ≤ 30 for youth with TS, or ≥ 9 but ≤ 20 for youth with CTD, and (d) IQ ≥ 75 on the Wechsler Abbreviated Scale of Intelligence (The Psychological Corporation, 1999). Exclusion criteria were (a) ≥ 3 sessions of previous behavioral treatment for tics, (b) positive diagnosis of a current or past substance use disorder, psychotic disorder, bipolar disorder, or schizophrenia, (c) report of significant suicidal ideation and/or attempts in the past 3 months, and (d) having begun, ended, or modified a psychiatric medication regimen in the past 4 weeks. In addition, children’s participation was terminated if they did not tic at least once per minute during the initial BL condition of the experiment. Children and their parents (n = 25 dyads) provided consent/assent and began participation. Seven youth did not meet study inclusion/exclusion criteria for the following reasons: one had previously undergone behavior therapy for TS, one did not tic once per minute during the initial BL condition, two did not meet the minimum tic severity requirement, one exceeded the maximum tic severity cutoff, and two did not meet diagnostic criteria for a tic disorder. Of the 18 qualifying participants, one withdrew assent during the preexperimental assessment, another’s participation was terminated due to problem behavior during the experiment,


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and another consistently failed manipulation checks designed to test for understanding of experimental instructions. These participants were excluded from analyses, resulting in the current sample of 15 participants, whose demographic and diagnostic information appear in Table 1. Of these 15 participants, 13 completed the experiment completely and accurately, one terminated his participation following the fourth of eight experimental conditions due to time constraints, and one’s tic data were lost due to equipment failure. Data from the latter two participants were included in present analyses when possible.

Measures YGTSS. The YGTSS is a structured, clinician-rated scale used to assess tic severity. This measure has excellent internal consistency and interrater reliability (Leckman, Riddle, Hardin, & Ort, 1989). Severity is rated for motor and vocal tics along several dimensions (number, frequency, intensity, complexity, and interference; range = 0-5 each), which are summed to yield a total severity score (range = 0-50) and separate motor and vocal severity scores (range = 0-25, each). Mini Neuropsychiatric Interview for Children (MINI-KID). The MINI-KID is a brief, psychometrically sound (Sheehan et al., 2010), structured interview that yields full diagnostic information on current Axis I psychiatric disorders. Wechsler Abbreviated Test of Intelligence (WASI). The WASI is a brief, psychometrically sound test of intellectual functioning for persons ages 6 to 89 (The Psychological Corporation, 1999). The two-subtest version was used to estimate full-scale IQ. PUTS. The PUTS is a nine-item, self-report measure in which respondents rate statements describing premonitory urges on a 4-point Likert-type scale anchored by not at all true and very true. Total PUTS scores range from a minimum of 9 to a maximum of 36. The PUTS has demonstrated good internal consistency (α = .81), temporal stability, and convergent and discriminant validity in treatment-seeking samples (Woods et al., 2005). Urge and Stress Thermometers. The Urge Thermometer and Stress Thermometer are adaptations of the 9-point “feelings thermometer” rating scale designed for measuring self-reports of symptom severity during administration of the Anxiety Disorders Interview Schedule-IV (Silverman & Albano, 1996).


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M

M

M

M

M

M

F

M

M

M

M

2

3

4

5

6

7

8

9

10

11

Gender

1

Subj. ID

10

14

11

8

12

10

12

14

10

15

10

Age

none

ADHD

ADHD

none

none

none

none

none

none

ADHD, Sep Anx none

Comorbid Diagnoses

27

15

26

28

26

16

22

16

17

26

19

YGTSS Score

22

27

19

14

9

11

14

9

9

25

18

PUTS Score

none

clonidine

none

none

none

none

none

none

none

none

none

Current Tic Medication Current Tics

(continued)

Motor: blocking, arm extension Vocal: sniffing, grunting, snorting, trilling Motor: head jerk, arm reaching, tapping, lip smacking Vocal: Screaming /ah/, humming /m/phoneme, /uh/ syllable Motor: Eyebrow raise, lip “smiling” + mouth opening, hand clenching, touching own chest Vocal: none current Motor: Hard blink + cheek tightening, hand to front of face Vocal: Sniffing, /m/ syllable Motor: Abdominal tensing, hand clenching Vocal: Grunting Motor: head jerking, foot dragging, pulling at fabric on clothing or surrounding objects Vocal: None current Motor: Rapid blinking, leg bouncing Vocal: Snorting, hiccupping Motor: rapid blinking, hard blinking, eye crossing, lip pursing + squinting, nose wiggling, arm extending, symmetrical tapping, overhead arm stretching Vocal: Snorting, gulping, lip vibrating Motor: facial grimacing, lip curling, neck stretching, knuckle popping, back arching Vocal: sniffing, throat clearing, squeaking, palilalia Motor: hard blinking, facial grimacing, mouth opening, bending to side Motor: Hard blinking, squinting, eyebrow raising, nose flaring, pelvic tensing, calf tensing, wrist bending, knuckle popping Vocal: Sniffing, coughing, throat clearing

Table 1. Demographic and Clinical Characteristics of Included Child Participants.

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M

M

M

13

14

15

11.4 (2.1)

10

9

12

9

Age

none

none

Agora, Specif, OCD

none

Comorbid Diagnoses

22.1 (4.7)

20

21

25

28

YGTSS Score

18.2 (7.0)

31

21

24

20

PUTS Score

guanfacine

none

none

clonidine

Current Tic Medication Current Tics

Motor: Hard blinking, eye rolling, face scrunching, head jerking, should shrugging, foot flexing, finger extending, full body tensing + holding breath Vocal: Snorting, throat clearing, squeaking, high-pitch screaming Motor: fast blinking, eye darting, eye squinting, eye widening, mouth stretching, head nodding, abdominal tensing, arm bending + hand tensing, echopraxia Vocal: Echolalia, pallilalia Motor: Rapid blinking, eyebrow raising, nose scrunching, glute tensing + arm flailing, wrist flicking Vocal: tongue clicking, throat clearing, snorting Motor: Hard blinking, lip rolling, mouth opening, mouth “smiling” tongue protruding, head shaking, head tilting, mouth popping Vocal: Sniffing, snorting, /s/ phoneme

Note. Subj. ID = Subject identification number; M = male; F = female; ADHD = Attention deficit hyperactivity disorder; Sep Anx = Separation anxiety; Agora = Agoraphobia; Specif = Specific phobia; OCD = obsessive compulsive disorder. Tic components joined by a “+” indicate individual units of complex tics.

M (SD)

F

Gender

12

Subj. ID

Table 1. (continued)

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Manipulation checks. Before each condition, the experimenter (M.R.C.) provided the child instructions and described the contingencies programmed for the upcoming condition. The experimenter asked the child to repeat the instructions, identify whether he or she was supposed to stop tics, and, when relevant, state how points were earned, how breaks were taken, and whether it was possible to earn points during breaks. If the child correctly summarized the instructions and contingencies placed on tics for the upcoming condition, the experimenter acknowledged that the response was correct and left the room. If the child answered incorrectly, the experimenter provided the correct answer(s) and prompted the child to answer again. Immediately following the termination of each condition, the experimenter asked the child questions to assess the child’s understanding of and compliance with the instructions for the just-terminated condition. Answers to these questions were recorded, but no feedback was provided regarding their accuracy.

Procedure Before the main experiment, a trained master’s-level clinician (J.E.T.) administered the YGTSS, WASI, and the MINI-KID and conducted a structured interview to determine if the child met inclusion/exclusion criteria. Qualifying participants were exposed to a series of eight experimental conditions in an ABACABAC modified alternating treatments design, with condition “A” corresponding to BL conditions, “B” to RTS conditions, and “C” to reinforced tic suppression with escape (RTS + E) conditions, during which tic suppression was reinforced, but participants could initiate free-to-tic breaks. Detailed descriptions of conditions are provided below. Participants completed all conditions in a single, continuous session. Prior to the start of the experiment, the experimenter oriented participants to the Urge and Stress thermometers using standardized instructions and anchored examples. After the participant completed this training to criterion, the initial BL condition began. Immediately prior to each condition, the experimenter read instructions describing the upcoming condition, conducted a pre-session manipulation check, and exited the room. Conditions started shortly (

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