Introduction
Skin picking is one of the self-injurious habits identified among individuals with impaired psychological function or mental illness. Self-injurious skin picking, also known as excoriation disorder (name used in DSM-5) or dermatillomania is characterized by repetitive and impulsive scratching, pulling, lancing, squeezing, picking, and gouging of one’s skin (Deckersbach et al., 2002). Skin picking can be operationally defined as an individual that impulsively breaks their skin in one or more ways just mentioned despite not having a dermatological condition.
Self-injurious skin picking occurs in both non-disabled individuals and people with developmental disabilities. It is more common in individuals with developmental disabilities and seems to be related to gender (females), obsessive-compulsive behaviors, anxiety, and depression (Lang et al., 2009). Skin picking can be detrimental to an individual’s life. Chronic skin picking can result in scars, tissue damage, skin lesions, ulcerations, and infections. As well as guilt, shame, and embarrassment of open sores, wounds, and scars (Deckersbach et al., 2002). People normally pick areas like arms, face, and neck. CPS is one of the self-injurious behaviors that predispose individuals to a high risk of infection and scarring resulting from tissue damage and sores that develop from the behavior (Deckersbach et al., 2002). Individuals who engage in skin picking also report significant psychological distress and impaired social functioning.
Applied Behavior Analysis is an evidence-based practice that would be greatly beneficial to individuals who engage in skin picking. Researchers have reported that habit reversal can be an effective behavior therapy in treating CSP behavior (Lang et al., 2009). Coping skills and replacement behavior can be taught so that this behavior is diminished if not completely stopped (Lang et al., 2009). This would allow these individuals to live healthier and happier lives. The present study evaluates the effectiveness of habit reversal in decreasing skin-picking behavior in the young male population with Autism Spectrum Disorder (ASD).
Participants and Setting
John is a 12-year-old male diagnosed with Autism Spectrum Disorder (ASD) who engages in chronic skin-picking. The participant is observed at his home and school for 3 hours at a time for 5 weeks. John was referred by his neurologist for treatment for his skin-picking. John’s parents reported that skin-picking began when he was 4 years old, but it has become chronic in the last 2 years. Around this time, the family moved to a new house, and John began to go to a new school. John’s parents report that the transition has been very hard for their son.
The interventions and treatment procedures were conducted within the clinic on a bi-weekly basis during planned treatment sessions held later in the afternoon. The sessions were an hour long. The room where the therapy sessions were held measured 13ft by 13ft, and it resembled a lounge room where the participant could access a chair, a couch a coffee table, a desk, and pillows. The desktop contained the following items: a clipboard, marker, and pencil for data collection. As data was collected, two RBTs, supervised by a BCBA, were always present in the treatment room.
Procedure
The therapist employed an ABAB reversal design to evaluate and observe the interventions. The baseline phase consisted of 20 days, followed by an intervention and reversal phase, each lasting 30 days, for a total of 60 days. The last phase was the fading phase which lasted 50 days. During the intervention, the therapist placed a small wicker basket on the coffee table that had different fidget and sensory toys like a pop bubble toy, fidget spanner, and spinner ring. The toys were tailor-modeled to John, and they remained on the coffee table for easy access throughout the intervention phase’s therapy sessions and the entire duration of each session. The therapist told John that he could earn a check mark for his board for utilizing the fidget and sensory toys, either through prompting or through his own volition, or if he did not pick his skin. If John used or held any of the fidget toys for at least 15 seconds, then such use was operationally deemed correct.
The therapist gave John a large board, placed on the therapy room’s wall where his reinforcement was recorded. A differential reinforcement procedure entailed writing a bold check mark using a marker pen on the board, and John could earn it if he used the fidget toys without prompting or abstained from picking his skin during the ten-minute intervals throughout the session. If John grabbed or used the fidget toy immediately after getting instruction following the observation of a skin-picking episode, he would earn a think check mark, written in pencil. The therapist involved John in reviewing all the criteria and the data collected after each session’s conclusion.
Once John earned eight check marks, he could exchange them for extra reinforcements like a drink, a snack item, a board game to play during the session, or a computer being availed in the room. John could choose to go and watch a movie for the entire duration of the next session if he earned all the bolded check marks for a session’s duration. Before each intervention phase, the therapist conducted an FBA to identify appropriate reinforcement for John.
At the treatment fading phase, the therapist offered differential reinforcement but eliminated the competing response of the fidget toys. John was reinforced for not picking his skin, but no reaction was given if the skin-picking behavior occurred. The therapist increased the interval for checkmark reinforcement at the midpoint of this phase from ten to twenty minutes.
Data Collection
In this experiment, a skin-picking episode began at the first instance of John picking his skin on a particular region and stopped when he abstained from picking for at least 5 seconds following the episode. The data collection was conducted on a continuous schedule frequency during each session, which was typically sixty minutes long (Cooper et al., 2020). Since it is difficult to record every occurrence of skin-picking behavior, the therapist defined and recorded each of the episodes of the behavior (Lang et al., 2009). The skin-picking behavior was recorded by two RBTs on a form placed on a clipboard with a pencil.
Interobserver Agreement
This is the degree to which at least two independent observers report the same values from observing the same events. When collecting data about behavior, it is advisable, therefore, to have more than one person recording the data. IOA data is crucial in revealing the clarity or the lack of clarity of an operational definition (Barlow et al., 2009). It helps in determining whether an observer requires extra training in data collection, among other useful information.
Trial-by-trial is an interobserver agreement that is appropriate when dealing with non-numerical data. The non-numerical data could include the example where the observer records “yes or no”. Also, trial-by-trial IOA does not need to involve interval data. It calculates the percentage of trials to which the observers can agree. It is obtained by dividing the number of agreement trials by the number of trials, then multiplying the product by one hundred percent (Barlow et al., 2009). The other types include interval by interval IOA, scored interval IOA, un-scored interval IOA, Total duration IOA, and Mean Duration –per occurrence IOA.
The two RBTs collecting the data throughout the sessions completed the interobserver agreement (IOA). For each session included in the experiment, each RBT independently recorded skin-picking sessions after every 10 minutes. During the sessions, the RBTs would sit across from each other, on the room’s opposite ends, both facing John and ensuring they did not see each other’s data collection forms while still having the client in full view. All the sessions during the study’s duration entailed the calculation of IOA. The study employed the trial-by-trial IOA method since it is a stringent and conservative method (Barlow et al., 2009). The calculation of IOA entailed taking the number of agreed-upon trials and dividing them by the total number of trials, then multiplying them by a hundred. The average agreement on skin-picking behavior and non-skin-picking behavior was 96%, from a range of 90% to 100%.
Design
Single-subject experimental designs, also known as within-subject or single-case experimental designs, are one of the most popular designs in CSD treatment interventions. It provides the framework for a quantitative, scientific approach where a participant acts as their experimental control (Barlow et al., 2009). It essentially entails the use of repeated measurements in understanding a person’s variability so that a scientist can use their knowledge of variability to determine how their therapy affects the individual.
A single-subject design has specific features that identify it. Firstly, an individual case is regarded as the unit of intervention and data analysis. Secondly, for comparison, the case provides its control (Barlow et al., 2009). For instance, John’s series of outcome variables can be measured before the intervention and then compared with measurements obtained during and after the intervention. Lastly, the outcome variable is measured several times, within and across varying levels of conditions of the independent variable.
Structurally, the single-subject experimental study describes the arrangement of its baseline and treatment phases. The conditions in a single-subject experiment are often assigned the letters A and B, with A denoting the baseline or the no intervention or treatment phase, while B is the experimental or treatment phase. At times, other letters are used to denote other experimental phases. The A phase generally serves as the duration in which the individual’s behavior of interest is counted or scored before the treatment is introduced (Cooper et al., 2020). The B phase, on the other hand, entails the period where the same behavior is scored or counted over time under intervention conditions while therapy is administered. The decisions concerning the therapy’s effect are then made by comparing the performance of the individual during the treatment, at phase B, and when there is no treatment.
The ABAB reversal design was the single-subject design implemented in this study. It was chosen because it could allow the therapist to individualize treatment, enable John to act as his control, and make it possible to have a clear visual analysis of the relevant conclusions (Barlow et al., 2009). Moreover, the ABAB reversal design enabled the strong demonstration of the functional relationship between the differential reinforcement procedures, skin-picking behavior, and the intervention of the competing response training (Deckersbach et al., 2002). Moreover, it allowed the therapist to observe quantifiable behavior change (Barlow et al., 2009). In this study, irreversibility was neither a concern nor a behavior of interest.
Conclusion
This section entails the results from the intervention, as summarized in Figures 1 and 2, below. The frequency of skin-picking episodes for each session for baseline, intervention, and treatment fading phases are detailed in Figure 1. The skin-picking episodes varied moderately during the baseline (M=15, range, 13, 23). However, the skin-picking episodes decreased during the intervention phase, compared to the baseline, with moderate variability (M=5; range, 0, 9). Overall, the intervention period had a descending trend.
The frequency of skin picking during the reversal analysis entailed moderate variability with both ascending and descending trends (M=11, Range, 7, 14). Nevertheless, the overall number of episodes was fewer than the baseline. Once the intervention phase was implemented, the frequency of skin-picking episodes reduced with a slight variability attaining a trend of zero (M=2, range, 0, 3). This showed that the skin episodes did not occur for five consecutive sessions in this phase. During the treatment fading phase, where only differential reinforcement was implemented, figure 2, a decrease in the frequency of appropriate behavior (M=, range, 10, 16) corresponded with an increase in skin-picking behavior (aggressive behavior; M=2, range, 0, 5). Nevertheless, the frequency remained remarkably lower than both baseline phases.
References
Barlow, D. H., Nock, M. K., & Hersen, M. (2009). Single case experimental designs: Strategies for studying behavior change (3rd ed.). Pearson Education.
Cooper, J. O., Heron, T. E., & Heward, W. L. (2020). Applied behavior analysis (3rd ed.). Pearson.
Deckersbach, T., Wilhelm, S., Keuthen, N., Baer, L., & Jenike, M. (2002). Cognitive-behavior therapy for self-injurious skin picking. Behavior Modifications, 26, 361-377.
Lang, R., Didden, R., Sigafoos, J., Rispoli, M., Regester, A., & Lancioni, G. E. (2009). Treatment of chronic skin-picking in an adolescent with Asperger syndrome and borderline intellectual disability. Clinical Case Studies, 8(4), 317-325. Web.