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

Hastings et al. (2001) worked with two young adults who ate non-food items. The team compared two ways to stop pica: blocking the hand only, or blocking plus giving a favorite snack right after.

Each method was tested in short sessions. The researchers counted how often pica happened and whether any aggression showed up.

Blocking alone cut pica but made the clients hit and pinch. Adding the edible redirect kept pica low and erased the aggression.

The simple add-on turned a punishing moment into a chance to eat something safe and tasty.

Frank-Crawford et al. (2025) later used the same redirect trick in a 33-person case series. Their larger study shows the 2001 tactic still works and now has stronger numbers behind it.

Ruckle et al. (2023) folded the redirect into a full package: discard training, response interruption, and matched competing items. The 2001 finding became one piece of a stronger toolkit.

Phillips et al. (2025) seems to clash—they saw blocking alone sometimes increase behavior. The key difference is they did not add redirection and their participants had mixed functions, not just automatic reinforcement.

If you block pica maintained by oral sensation, immediately offer a preferred bite. This single step prevents the aggression that pure blocking can spark and keeps treatment humane. Use it alone for quick wins or fold it into larger packages like Frank-Crawford and Ruckle do for even better outcomes.