Broadly stated, pica is the term given to the compulsive consumption of substances not generally considered food. However, a precise definition of pica is somewhat elusive because understandings of what constitutes “food,” what symptoms signify pica, and explanations of what causes the condition vary with historical and cultural context. A more specific definition of pica is “the chronic, compulsive eating of nonfoods such as earth, ashes, chalk, and lead-paint chips …” (Hunter 1973: 171), but it may also include a “false or craving appetite” or “deliberate ingestion of a bizarre selection of food,” as well as the compulsive ingestion of nonnutritive or nonfood items such as ice and ice water (Parry-Jones and Parry-Jones 1994: 290).

Pica, in various forms, has been widely noted historically and geographically, primarily in medical texts and anthropological writings (see, for example, Laufer 1930; Cooper 1957; Anell and Lagercrantz 1958). Its practice, although not considered a disease, is of medical concern because ingestion of some substances may result in disease. Additionally, there are types of pica that have been linked by medical researchers to the correction of mineral deficiencies (see, for example, Coltman 1969; Crosby 1971; Hunter 1973). Pica is classified by the DSM-III-R (American Psychiatric Association 1987) and the ICD-10 of the World Health Organization (1992) as an eating disorder, along with anorexia nervosa, bulimia, and infant rumination. Various forms of pica have also been associated with mental retardation.