Using differential reinforcement of a discard response to treat pica

Previous research on the treatment of pica (i.e., the ingestion of inedible objects) is limited compared to research on the treatment of other types of severe problem behavior. This study involved the use of differential reinforcement of alternative behavior, with a discard response as the alternative behavior, to treat pica presented by a 13‐year‐old girl with an autism spectrum disorder. We extended previous research by thinning the schedule of reinforcement for the alternative response. Substantial reductions in pica were obtained. Limitations and future directions in the treatment of pica are discussed.     

Functional assessment and treatment of pica: a single‐case experiment

The pica of a 6‐year‐old girl diagnosed with autism was initially shown to persist in the absence of socially mediated consequences. In an attempt to provide a competing source of oral stimulation, we used a stimulus preference assessment to identify food items that were subsequently presented noncontingently. However, the noncontingent schedule could not be thinned to a practical variation while still maintaining reductions in pica. A subsequent multielement evaluation of response blocking and verbal reprimands demonstrated that neither intervention both produced and maintained low levels of pica. Verbal reprimands were then used in conjunction with noncontingent food presentation, but this intervention did not produce significant reductions in pica. Suppression of pica was ultimately obtained in both a clinic setting and in the child's natural environment using contingent, varied auditory stimulation. The results are discussed in the context of the ‘least restrictive alternative’ model of treatment selection. Copyright © 2001 John Wiley & Sons, Ltd.     

Comparison of blocking strategies informed by precursor assessment to decrease pica

Pica is dangerous behavior and often maintained by automatic reinforcement. We conducted a latency functional analysis (FA) using safe consumption items to verify that pica was maintained in part by automatic reinforcement and exclude participants for whom pica was likely maintained solely by attention. Next, we identified precursors to pica through a probability analysis and conducted a brief blocking assessment for participants' whose pica occurred in the alone and attention conditions of the FA. Finally, we compared blocking precursors with pica, touching an inedible item and the pica itself. Results showed that five of the six participants' pica was likely maintained by automatic reinforcement, and pica decreased during the brief blocking assessment for three of four participants. Results of the blocking comparison showed that blocking behaviors earlier in the response hierarchy was as effective as only blocking pica attempts for two participants and more effective for one participant.     

Response Interruption and Differential Reinforcement of Alternative Behavior for the Treatment of Pica

Pica displayed by two individuals with autism was decreased by a treatment involving differential reinforcement and response interruption that altered the chain of behavior involved in pica (i.e., picking up items and placing them in the mouth). The treatment involved establishing prompts to ‘clean‐up’ as a new discriminative stimulus (SD) for picking up items from the floor; and holding potential pica items was established as an SD for discarding those items in a trash receptacle, putting them away, or using them appropriately. After demonstrating the effectiveness of the treatment in an analog setting, the treatment package was systematically generalized to community settings. Copyright © 2011 John Wiley & Sons, Ltd.     

Varying response effort in the treatment of pica maintained by automatic reinforcement

Pica is a life-threatening behavior displayed by many individuals with developmental disabilities. In the current study, automatic reinforcement maintained the pica of 3 participants. Following functional analyses of pica, response-effort manipulations were conducted in which the effort to obtain pica or alternative items was varied systematically. Several general relations emerged as a result of the study. First, levels of pica were reduced relative to baseline when alternative items were available independent of the effort required to obtain alternative items or pica. Second, increasing the effort for alternative items resulted in increases in pica relative to when effort for alternative items was low. Third, increasing response effort for pica produced reductions in pica relative to baseline when alternative items were unavailable. Fourth, the highest levels of pica occurred when the effort to engage in pica was low or medium and no alternative items were available. These findings are discussed in terms of the relative effects of quality of reinforcement and response effort on behavior.     

Brief assessment and treatment of pica using differential reinforcement,response interruption and redirection,and competing stimuli

Pica is a life threating form of challenging behavior displayed by individuals with intellectual and developmental disabilities. In most cases, pica is maintained by automatic reinforcement. Common interventions for pica use some combination of response blocking, response interruption and redirection (RIRD), differential reinforcement of alternative behavior (DRA), and noncontingent reinforcement with competing stimuli. However, there is need for additional research regarding DRA procedures that emphasize skills acquisition by teaching alternative behaviors that modify the established behavioral chain of pica responses that occur in the presence of non-edible stimuli. There is also a need to examine the generality of recent advances in competing stimulus assessment (CSA) methodologies—namely, the augmented-CSA (A-CSA)—to pica. Thus, the purpose of the present investigation was to systematically replicate and extend previous research for the assessment and treatment of pica in an individual with IDD. First, we conducted a functional analysis to identify environmental variables associated with pica. Next, taught Patrick a differential response (i.e., discard pica items in trash receptacle) to earn reinforcers in conjunction with a RIRD procedure. Finally, we conducted an A-CSA for pica. Overall, low rates of pica were maintained over time with a combination of these procedures, and treatment was generalized across settings and people.     

TREATMENT OF PICA THROUGH MULTIPLE ANALYSES OF ITS REINFORCING FUNCTIONS

We conducted functional analyses of the pica of 3 participants. The pica of 1 participant appeared to be maintained by automatic reinforcement; that of the other 2 participants appeared to be multiply controlled by social and automatic reinforcement. Subsequent preference and treatment analyses were used to identify stimuli that would compete with the automatic function of pica for the 3 participants. These analyses also identified the specific aspect of oral stimulation that served as automatic reinforcement for 2 of the participants. In addition, functional analysis-based treatments were used to address the socially motivated components of 2 of the participants' pica. Results are discussed in terms of (a) the importance of using the results of functional analyses to develop treatments for pica and (b) the advantages of developing indirect analyses to identify specific sources of reinforcement for automatically reinforced behavior.     

FUNCTIONAL ANALYSIS AND TREATMENT OF CIGARETTE PICA

A series of analyses was conducted to assess and treat the pica of cigarette butts by a young man with mental retardation and autism. First, we demonstrated that pica was maintained in a condition with no social consequences when the available cigarettes contained nicotine but not when the cigarettes contained herbs without nicotine. Second, a choice assessment (Fisher et al., 1992) confirmed that tobacco was preferred over the other components of the cigarette (e.g., paper, filter, etc.). Third, an analogue functional analysis (Iwata, Dorsey, Slifer, Bauman, & Richman, 1982/1994) demonstrated that cigarette pica was maintained independent of social consequences. Fourth, a treatment designed to interrupt the hypothesized response—reinforcer relationship reduced consumption of cigarettes to zero. Finally, because cigarette pica occurred primarily when the individual was alone or under minimal supervision, a procedure based on stimulus control was developed to improve the effectiveness of the intervention in these situations.     

Parent treatment of complex pica in a teen with autism

Pica is a severe behavior disorder involving the persistent consumption of nonnutritive substances. Due to health complications and risks for fatality, designing effective behavioral treatments that are feasible for implementation by family members at home is imperative. This case report presents a parent-conducted functional analysis and treatment evaluation of automatically maintained pica in a teenager with autism spectrum disorder. Initial treatment with a competing stimulus was effective when paired with response interruption and redirection. Although effective, this combination of treatment components required very close parental proximity and led to increases in untargeted body-oriented pica (e.g., ingestion of skin, hair, and nails). Upon extending treatment to include the second topography of pica, both the originally targeted (object-oriented) pica and body-oriented pica decreased. Nonetheless, treatment effects were not sustained while fading parent proximity. The treatment was then augmented a third time with response cost. This final treatment package produced clinically significant reductions in all pica, facilitated parent proximity fading until the participant was alone, extended to their home, and maintained over a year of follow up.     

Behavioral Treatment of Pica in Children with Lead Poisoning

Lead poisoning, a serious problem that can result in permanent neurological damage, often results from the ingestion of inedible substances that contain lead. The behavior of ingesting nonedible substances in termed pica. In this study, behavior modification procedures were used to eliminate pica in three young children with lead poisoning. Three kinds of procedures were used: (1) discriminate training, in which the subject was taught to recognize that paint and several objects were not edible; (2) reinforcement for the absence of pica; and (3) overcorrection for the occurence of pica. Pica was eliminated in all three subjects. While it was not always clear which component of the treatment was responsible for the decrease, the sequence used had the advantage of an effictive clinical technique proceeding from least to progressively more restrictive procedures.     

The effects of a vitamin supplement on the pica of a child with severe mental retardation

The effects of a common multiple vitamin on the pica of a child with severe mental retardation and anemia were evaluated. A BAB design revealed that pica was decreased by the vitamin. The results suggest that pica can be effectively treated by implementation of a simple nutritional or biological intervention. Further research investigating the generality of this finding and the effects of combining biological and behavioral interventions are discussed.     

Further Evidence for Swimming-Based Pica in Rats

Aberrant pica behavior (i.e., kaolin clay ingestion) has been regarded as a behavioral marker of nausea in rats that cannot vomit because of anatomical and/or neural reasons. The previous study reported that a single swimming session of 40 min generated pica behavior, implying that swimming induces nausea in rats. However, the rats tested in that report were not experimentally naive. The present study successfully replicated swimming-based pica with experimentally naive rats (Experiment 1). It also showed that pica was observed with pool confinement of 20 min but not with that of 10 min (Experiments 2A and 2B) and that roaming in shallow water did not generate pica (Experiment 3). These results taken together suggest that swimming for at least 20 min induces nausea in rats, implying that rats’ taste aversion learning based on swimming is mediated by gastrointestinal discomfort.     

A long-term case study of analysis,response suppression,and treatment maintenance involving life-threatening pica

Behavioral assessment and intervention strategies used to treat chronic, life-threatening pica in an institutionalized, 16-year-old male with profoundly retarded collateral self-injurious and aggressive conduct, are described and evaluated. Thirty-minute observation sessions, conducted under baited contitions, revealed that bait saliency and the absence of caregiver supervision were discriminative for high rates of pica. Oral delivery of response-contingent lemon juice suppressed pica to near zero rates, while a procedural package incorporating delivery of water mist contingent on response-antecedant wandering contributed to further reductions in pica. Considerable suppression was maintained for approximately 18 months, with administration by paraprofessional staff. Data spanning nearly four years indicated that pica suppression was primarily a function of the introduction, maintenance, and withdrawal of aversive contingencies, rather than of concurrent schedules of positive reinforcement. Positive and negative side effects, and ethical questions associated with the use of aversive stimuli in treating life-threatening behavior, are discussed.     

MULTICOMPONENT ASSESSMENT AND TREATMENT OF CIGARETTE PICA

We conducted a multicomponent assessment and treatment for 4 individuals who engaged in cigarette pica. During Phase 1, three stimulus preference assessments were conducted to identify (a) the reinforcing component of the cigarette, (b) potential alternative reinforcers that may be used during treatment, and (c) whether the alternative reinforcer would compete effectively with cigarettes. Results were successful in identifying the reinforcing component of the cigarette and suggested the feasibility of using alternative reinforcers during treatment to eliminate cigarette pica. During Phase 2, the effects of two treatment procedures were evaluated. Noncontingent reinforcement (NCR) with the alternative edible reinforcer reduced the pica of 2 of the participants, but effects were not maintained when the initial dense schedule of NCR was thinned. Subsequently, differential reinforcement of alternative behavior with the alternative edible reinforcer was effective in reducing pica for 3 participants. An evaluation of nine treatment procedures failed to identify an effective intervention for the remaining participant; consequently, preventive measures were designed to minimize occurrences of cigarette pica.     

FUNCTIONAL ANALYSIS AND TREATMENT OF SEVERE PICA

A two-phase functional analysis of a profoundly retarded 19-year-old male's pica facilitated the design of an effective intervention containing no aversive components. In the first analysis, frequent staff-client interaction resulted in 25% and 66% less pica than limited and no interaction, respectively. Paradoxical effects were obtained in the second analysis, where no protective helmet resulted in 38% and 26% less pica than the helmet with face shield and helmet without face shield, respectively. On the basis of these analyses, limited interaction and no helmet conditions were combined in an effective, staff-implemented treatment at a medium-sized institution.     

Response blocking with and without redirection for the treatment of pica.

Although response blocking can decrease problem behavior, one potential adverse side effect is the induction of aggression. In the current study, we report on a young adult who engaged in high rates of pica maintained by automatic reinforcement. Blocking pica, however, led to aggression. When redirection to an alternative preferred food item was added to an intervention consisting of response blocking, pica was effectively treated without increasing aggression.     

Treatment of Comorbid Pica and Generalized Anxiety Disorder: A Case Study

This case report describes the assessment and treatment of a treatment-naïve 36-year-old Hispanic/Latina female with comorbid pica and generalized anxiety disorder (GAD), and iron-deficiency anemia. At the onset of treatment, the client consumed chalkboard chalk and vermiculite from potting soil approximately three times per week and presented with moderate-severity GAD. Assessment and treatment occurred over 24 weekly outpatient individual sessions. Treatment was delivered in concert with medical intervention to address anemia. A cognitive-behavioral case formulation was developed from multiple assessment sources. A process-based cognitive-behavioral therapy (CBT) intervention approach was used to target GAD and pica simultaneously, which included psychoeducation, self-monitoring, arousal reduction skills, cognitive training (reappraisal, distancing), and behavior modification/stimulus control techniques. Barriers to treatment and their solutions are discussed. At the end of treatment, the client demonstrated increased insight and understanding of her worry symptoms and pica behavior, acquired cognitive skills and arousal reduction strategies for managing GAD, and reported less than one episode of pica per week. The identified assessment and treatment approach is worthy of future investigation to inform empirically based treatment development efforts, especially for pica.     

A PRELIMINARY EVALUATION OF EMPIRICALLY DERIVED CONSEQUENCES FOR THE TREATMENT OF PICA

Individualized treatment packages were developed for 3 children with high-rate severe pica using a discrimination training paradigm and a behavioral assessment-based procedure known as empirically derived consequences. Children received empirically derived reinforcers for eating under appropriate stimulus conditions (i.e., eating food only from a plate and placemat that served as a discriminative stimulus) and empirically derived punishers for attempts to engage in pica. This treatment package resulted in marked reductions in pica and an increase in appropriate eating for all 3 children in a “baited” analogue condition. In addition, low rates of pica were maintained for 9 months for all 3 children. These results suggest that treatment effectiveness may be enhanced when behavioral assessment data are used to identify potent consequences.     

An analysis of response-blocking parameters in the prevention of pica

We manipulated two parameters of response blocking to reduce pica: (a) the criteria for initiating the procedure (either earlier or later in the response chain) and (b) the distance from which the procedure was initiated. Results suggested that response blocking may be effective only when implemented early in the chain and with near-perfect consistency. Further, additional treatment components may be required to eliminate all pica attempts.     

Outpatient Treatment of Pica in a Developmentally Delayed Child

A multiple baseline design was employed to evaluate the effectiveness of over correction and differential reinforcement to reduce pica in a 4-year-old developmentally delayed boy. Parents and classroom staff were trained as mediators of treatment by a behavioral consultant. Despite the effectiveness of the procedure, treatment mediators terminated intervention, therefore, an alternative program consisting of positive reinforcement and time-out was implemented according to a reversal design. Pica was measured via direct observation and parental monitoring during a variety of activities, including fine motor tasks, gross motor play, and independent play. Results indicated clear reductions in pica as a result of both interventions. Implications for future clinical practice and research are discussed.