Ingesting or craving of substances with no nutritional value.
Examples of substances may include dirt, paint chips, clay, leaves, pebbles, etc. Pica is considered a disorder when the behavior is not developmentally appropriate (e.g., >18–24 mo) and persists for at least 1 month. The course of pica is most often in the range of months, rather than years. It is most common in children but has also been studied in pregnant women. The etiology of pica has not empirically been determined, but hypotheses include nutritional deficiencies, cultural factors (ingestion of starch, soil, or clay is regarded as acceptable by various groups), low socioeconomic status, learned behavior (especially in children with developmental disabilities), or underlying biochemical disorder. Prevalence is unclear, because it is often unrecognized and underreported. Pica is a potentially serious disorder depending on the toxicity of the substance being ingested (such as the ingestion of...