Pica involves the eating of non-nutritive, non-food substances inappropriate to the developmental level of the individual. Non-food substances may include soil, clay, paper, coal, wood, string, pebbles or hair. Research into Pica is limited and the prevalence may be under-reported due to feelings of embarrassment.

Due to the nature of the disorder, Pica can lead to medical complications such as lead poisoning, intestinal problems and mineral deficiencies. Due to tooth damage, dental problems may also arise.

Iron deficiencies may be an underlying factor in some cases. Some individuals with developmental disabilities may be affected by Pica. This may in part be due to their inability to distinguish between food and non-food items. Small scale studies have pointed to feelings of compulsion and obsession in some individuals affected by Pica, suggesting obsessive compulsive disorder (OCD) may be a factor in some cases.