Brief assessment and treatment of pica using differential reinforcement, response interruption and redirection, and competing stimuli
Have the client throw pica items into a trash can for DRA, add brief RIRD and A-CSA-matched items, and pica stays low across settings.
01Research in Context
What this study did
Ruckle and team worked with one adult who had an intellectual disability and long history of pica. First they ran a 30-minute brief assessment to see how often the client mouthed or ate non-food items.
Next they tested three parts at once: DRA for tossing pica items into a trash can, brief RIRD when pica started, and items picked from an A-CSA that matched the sensory feel of pica. They tracked pica across rooms and staff.
What they found
Pica dropped from about five times per session to near zero once the package began. The low rate stayed for three months with no extra planning.
Effects moved to new places and new people without retraining. Staff only needed a 5-minute booster one month in.
How this fits with other research
Cividini-Motta et al. (2019) showed RIRD alone can cut stereotypy, but appropriate responses did not grow. Ruckle adds a clear DRA response (discard) plus A-CSA items, giving the client something to do instead of just stopping.
Breeman et al. (2025) took the same A-CSA tool and added functional-analysis subtypes for stereotypy. Their effects were weaker and less steady, showing the pica package in Ruckle may work because pica has a strong automatic payoff that matched items easily replace.
Kirkwood et al. (2021) also paired differential reinforcement with extinction for multiply controlled mealtime behavior. Both studies find that matching the function matters, but Ruckle shows you can skip formal FA if a quick A-CSA finds the right sensory substitute.
Why it matters
If you have a client who eats items off the floor, teach the trash-toss response as the DRA. Run a 10-minute A-CSA first to pick 2-3 items that feel like the pica objects. Then use 3-second RIRD when pica starts while you hand over the matched item. You can finish the whole assessment and plan in one afternoon and see clear drops the same week.
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02At a glance
03Original abstract
AbstractPica 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.
Behavioral Interventions, 2023 · doi:10.1002/bin.1881