Pica is generally defined as the consumption of nonnutritive items, which is inappropriate for developmental age, continues for more than a month, and is not part of a culturally sanctioned practice. In other words, pica involves eating items that are not food for at least one month, and the individual must be “too old” to be putting things into their mouth (i.e., individuals over the age of 2 years). Anywhere from 6 to 26% of individuals with intellectual disabilities (ID) may engage in pica, and the behavior is more likely if the individual is diagnosed with autism or has more significant intellectual disabilities.
Individuals with ID have been reported to engage in pica with many different types of items including cigarette butts, paper, paint chips, rocks, sticks, and dirt, just to name a few. Depending on what the individual eats, pica can be quite dangerous and lead to infection, blockage, breaks or holes in the stomach or intestine, and choking. Paint chips and dirt can contain lead, so eating these items can result in lead poisoning.
In rare cases, people who engage in pica may not be getting enough of certain minerals in their diet, such as iron. However, even in these cases, once the mineral problem is fixed, pica often continues and requires additional treatment. Behavioral interventions have been shown to be effective at reducing pica by individuals with intellectual disabilities.
References for Further Reading:
Beavers GA, Iwata BA, Lerman DC. (2013). Thirty years of research on the functional analysis of problem behavior. Journal of Applied Behavior Analysis, 46(1), 1-21.
Hagopian LP, Rolider NU, Rooker GW. (2011). Behavioral assessment and treatment of pica. In J. K. Luiselli (Ed.), The handbook of high-risk challenging behaviors in people with intellectual and developmental disabilities (pp. 161-176). Baltimore, MD: Brookes Publishing.
Carter SL. (2009). Treatment of pica using a pica exchange procedure with increasing response effort. Education and Training in Developmental Disabilities, 44(1), 143-147.
Wasano LC, Borrero JC, Kohn CS. (2009). Brief report: A comparison of indirect vs. experimental strategies for the assessment of pica. Journal of Autism and Other Developmental Disorders, 39(11), 1582-1586.
Iwata BA, Dozier CL. (2008). Clinical application of functional analysis methodology. Behavior Analysis in Practice, 1(1), 3-9.
Kern L, Starosta K, Adelman BE. (2006). Reducing pica by teaching children to exchange inedible items for edibles. Behavior Modification, 30(2), 135-158.
Stiegler LN. (2005). Understanding pica behavior: A review for clinical and educational professionals. Focus on Autism and Other Developmental Disabilities, 20, 27-38.
Hanley GP, Iwata BA, McCord BE. (2003). Functional analysis of problem behavior: A review. Journal of Applied Behavior Analysis, 36(2), 147–185.
Ricciardi JN, Luiselli JK, Terrill S, Reardon K. (2003). Alternative response training with contingent practice as intervention for pica in a school setting. Behavioral Interventions, 18, 219-226.
Piazza CC, Roane HS, Keeney KM, Boney BR, Abt KA. (2002). Varying response effort in the treatment of pica maintained by automatic reinforcement. Journal of Applied Behavior Analysis, 35(3), 233-246.
Hagopian LP, Adelinis JD. (2001). Response blocking with and without redirection for the treatment of pica. Journal of Applied Behavior Analysis, 34(4), 527-530.
Rose EA, Porcerelli JH, Neale AV. (2000). Pica: Common but commonly missed. Journal of the American Board of Family Medicine, 13(5), 353-358.
Goh HL, Iwata BA, Kahng SW. (1999). Multicomponent assessment and treatment of cigarette pica. Journal of Applied Behavior Analysis, 32(3), 297-316.
Matson JL, Bamburg JW. (1999). A descriptive study of pica behavior in persons with mental retardation. Journal of Developmental and Physical Disabilities, 11, 353-361.
Fisher WW, Piazza CC, Bowman LG, Kurtz PF, Sherer MR, Lachman SR. (1994). A preliminary evaluation of empirically derived consequences for the treatment of pica. Journal of Applied Behavior Analysis, 27(3), 447-457.
Iwata BA, Dorsey MF, Slifer KJ, Bauman KE, Richman GS. (1994). Toward a functional analysis of self-injury. Journal of Applied Behavior Analysis, 27(2), 197-209. (Reprinted with permission from Analysis and Intervention in Developmental Disabilities, 2, 3-20, 1982)
Paniagua FA, Braverman C, Capriotti RM. (1986). Use of a treatment package in the management of a profoundly mentally retarded girl’s pica and self-stimulation. American Journal of Mental Deficiency, 90(5), 550-557.
Danford DE, Huber AM. (1982). Pica among mentally retarded adults. American Journal of Mental Deficiency, 87(2), 141-146.
Foxx RM, Martin ED. (1975). Treatment of scavenging behavior (coprophagy and pica) by overcorrection. Behaviour Research and Therapy, 13(2-3), 153-162.