Using differential reinforcement of a discard response to treat pica

The team worked with a 13-year-old girl who had autism and pica.

They taught her to throw away items instead of eating them.

Each time she discarded, she got a favorite snack or toy.

Later they gave rewards less often to see if the skill stuck.

Pica drops stayed big even when rewards came only now and then.

The girl kept tossing objects into the trash on her own.

No extra punishment or gear was needed.

Matson et al. (1999) also saw DRA beat NCR when they thinned the schedule for cigarette pica.

Thomas et al. (2023) later showed parents can run a bigger home package—competing items, RIRD, plus response cost—and still keep pica down for a year.

Morris et al. (2021) ran a quick home FA first, then used DR of mands instead of discard; both studies got large drops, proving you can pick the replacement response that fits the child.

Rojahn et al. (1987) used water-mist punishment and got fast suppression too, but Slocum’s reinforcement-only method avoids any aversive side effects.

You now have a low-intrusion option for pica: teach “throw it away,” reinforce, then thin.

No need for helmets, sprays, or time-out.

Start with dense reinforcement, stretch the intervals, and watch the skill survive in real-life clutter.