Pica (disorder)

Pica
Stomach contents of a psychiatric patient with pica: 1,446 items, including "457 nails, 42 screws, safety pins, spoon tops, and salt and pepper shaker tops".
Pronunciation
SpecialtyPsychiatry
Causes

Pica (/ˈpaɪkə/ PY-kə) is the psychologically compulsive craving or consumption of objects that are not normally intended to be consumed.[2] It is classified as an eating disorder but can also be the result of an existing mental disorder.[3] The ingested or craved substance may be biological, natural, or manmade. The term was drawn directly from the medieval Latin word for the Eurasian magpie, a bird subject to much folklore regarding its opportunistic feeding behaviors.[4]

According to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), pica as a standalone eating disorder must persist for more than one month at an age when eating such objects is considered developmentally inappropriate, not part of culturally sanctioned practice, and sufficiently severe to warrant clinical attention. Pica may lead to intoxication in children, which can result in an impairment of both physical and mental development.[5] In addition, it can cause surgical emergencies to address intestinal obstructions, as well as more subtle symptoms such as nutritional deficiencies, particularly iron deficiency, as well as parasitosis.[5] Pica has been linked to other mental disorders. Stressors such as psychological trauma, maternal deprivation, family issues, parental neglect, pregnancy, and a disorganized family structure are risk factors for pica.[5][6]

Pica is most commonly seen in pregnant women,[7] small children, and people who may have developmental disorders such as autism.[8] Children eating painted plaster containing lead may develop brain damage from lead poisoning. A similar risk exists from eating soil near roads that existed before the phase-out of tetraethyllead or that were sprayed with oil (to settle dust) contaminated by toxic PCBs or dioxin. In addition to poisoning, a much greater risk exists of gastrointestinal obstruction or tearing in the stomach. Another risk of eating soil is the ingestion of animal feces and accompanying parasites. Cases of severe bacterial infections occurrence (leptospirosis) in patients diagnosed with pica have also been reported.[9] Pica can also be found in animals such as dogs[10] and cats.[11]

Signs and symptoms

Chalky stone composed of kaolinite with traces of quartz, small pieces of which were sucked on by a person with pica

Pica is the consumption of substances with no significant nutritional value such as soap, plaster, plastic or paint. Subtypes are characterized by the substance eaten:[12]

This eating pattern should last at least one month to meet the time diagnostic criteria of pica.[20]

Complications

Complications may occur due to the substance consumed. For example, lead poisoning may result from the ingestion of paint or paint-soaked plaster,[21] hairballs may cause intestinal obstruction, and Toxoplasma or Toxocara infections may follow ingestion of feces or soil.[22]

Causes

Pica is currently recognized as a mental disorder by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). According to the DSM-5, mineral deficiencies are occasionally associated with pica, but biological abnormalities are rarely found.[3] People practicing forms of pica, such as geophagy, pagophagy, and amylophagy, are more likely to be anemic or to have low hemoglobin concentration in their blood, lower levels of red blood cells (hematocrit), or lower plasma zinc levels.[23] Specifically, practicing geophagy is more likely to be associated with anemia or low hemoglobin.[23] Practicing pagophagy and amylophagy is more highly associated with anemia.[23]

Mental health conditions such as obsessive–compulsive disorder (OCD) and schizophrenia have been proposed as causes of pica.[24] More recently, cases of pica have been tied to the obsessive–compulsive spectrum, and a move has arisen to consider OCD in the cause of pica.[25] Sensory, physiological, cultural, and psychosocial perspectives have also been used to explain the causation of pica.[26][27][28][29][30][31]

Pica may be a cultural practice not associated with a deficiency or disorder. Ingestion of kaolin (white clay) among African American women in the US state of Georgia shows the practice to be a DSM-4 "culture-bound syndrome" and "not selectively associated with other psychopathology".[32] Similar kaolin ingestion is also widespread in parts of Africa.[33] Such practices may stem from purported health benefits, such as the ability of clay to absorb plant toxins and protect against toxic alkaloids and tannic acids.[34]

Diagnosis

No single test confirms pica, but because pica can occur in people who have lower than normal nutrient levels and poor nutrition (malnutrition), the health care provider should test blood levels of iron and zinc. Hemoglobin can also be checked to test for anemia. Lead levels should always be checked in children who may have eaten paint or objects covered in lead-paint dust. The healthcare provider should test and monitor for infection if the person has been eating contaminated soil or animal waste.[20]

DSM-5

The DSM-5 posits four criteria that must be met for a person to be diagnosed with pica:[3]

  1. Person must have been eating non-nutritive nonfoods for at least one month.[3]
  2. This eating must be considered abnormal for the person's stage of development.[3]
  3. Eating these substances cannot be associated with a cultural practice that is considered normal in the social context of the individual.[3]
  4. For people who currently have a medical condition (e.g.: pregnancy) or a mental disorder (e.g.: autism spectrum), the action of eating non-nutritive nonfoods should only be considered pica if it is dangerous and requires extra medical investigation or treatment on top of what they are already receiving for their pre-existing condition.[3]

Differential diagnosis

In individuals with autism, schizophrenia, and certain physical disorders (such as Kleine–Levin syndrome), non-nutritive substances may be eaten.[3] In such instances, pica should only be noted as an additional diagnosis if the eating behaviour is sufficiently persistent and severe to warrant additional clinical attention.[3]

Treatment

Both psychotherapeutic and pharmacological interventions for pica have been criticized for low evidence quality.[35] It is recommended that treatment options for pica vary by patient and suspected causes.[35] Pica may often fade on its own when in pregnant women or children,[36] though treatment and routine evaluation are advised due to potentially serious consequences.[35]

Due to its impact on physical health, pica may require a vast assortment of experts to be managed, and it is recommended that physical health conditions be addressed prior to treatment.[35] An initial approach often involves screening for, and if necessary, treating any mineral deficiencies or other comorbid conditions.[8] From there, treatment may primarily involve decreasing access to the craved substance or providing a supplement, especially for at-risk patients (e.g. pregnant women).[37] Iron deficiencies or other nutrient deficiencies should be treated using dietary supplements and through dietary changes.[37][38][39]

Certain psychotherapeutic approaches have been found helpful for pica. Behavior-based treatment options can be useful for people who have a developmental disability or mental illness.[37][36] These treatments may involve teaching strategies to help patients alter their responses to certain stimuli. Behavioral treatments have been shown to reduce pica severity by 80% in people with intellectual disabilities.[40] Aversion therapy is another option, wherein the person learns through positive reinforcement and mild aversions which foods are good and which ones they should not eat.[37][36] Differential reinforcement is also commonly used to block pica responses by redirecting focus to other activities.[37][36]

Use of medication in pica treatment is generally scarce when not aimed at treating underlying conditions, as no existing pharmacological intervention is specifically tailored towards pica.[35][37] Antipsychotic medication is recommended in certain instances, though is generally cautioned against due to side-effects and the anecdotal nature of evidence.[37][36] SSRIs have been successfully used for pica associated with OCD.[41] A case-report found that asenapine resulted in significant improvement on a woman with several mental health conditions after bariatric surgery,[42] whereas another found use in venlafaxine for pica associated with depression.[43] Reports prior to these publications have cautioned against the use of medication until all non-psychogenic causes have been ruled out.[44]

Epidemiology

The prevalence of pica is difficult to establish because of differences in definition and the reluctance of patients to admit to abnormal cravings and ingestion,[5] thus leading to the prevalence recordings of pica among at-risk groups being in the range of 8% to 65% depending on the study.[7] Based on compiled self-report and interview data of pregnant and postpartum women, pica is most prevalent geographically in Africa, with an estimated prevalence of 44.8%, followed by North and South America (23.0%) and Eurasia (17.5%).[45] Factors associated with Pica in this population were determined to be anemia and low levels of education, both of which are associated with low socioeconomic backgrounds.[45] Two studies of adults with intellectual disabilities living in institutions found that 21.8%[46] and 25.8%[47] of these groups had pica.[48]

Prevalence rates for children are unknown.[48][49] Young children commonly place non-nutritious material into their mouths. This activity occurs in 75% of 12-month-old infants, and 15% of two- to three-year-old children.[49]

In institutionalized children with mental disabilities, pica occurs in 10–33%.[49]

History

The condition currently known as pica was first described by Hippocrates.[50]

The term pica originates in the Latin word for magpie, pīca,[4][51] a bird famed for its unusual eating behaviors and believed to eat almost anything.[52] The Latin may have been a translation of a Greek word meaning both 'magpie, jay' and 'pregnancy craving, craving for strange food'.[53][54] In 13th-century Latin work,[clarification needed] pica was referenced by the Greeks and Romans;[when?] however, it was not addressed in medical texts until 1563.[8]

In the southern United States in the 1800s, geophagia was a common practice among the slave population.[8] Geophagia is a form of pica in which the person consumes earthly substances such as clay, and is particularly prevalent to augment a mineral-deficient diet.[55] Kaolin was consumed by slaves from West African in the Southeastern United States, particularly the Georgia belt, due to the antidiarrheal qualities in the treatment of dysentery and other abdominal ailments.[56] The practice of consuming kaolin rocks was thereafter studied scientifically, the results of which led to the subsequent pharmaceutical commercialization of kaolinite, the clay mineral contained in kaolin. Kaolinite became the active ingredient in antidiarrheal drugs such as Kaopectate, although it was replaced by attapulgite in the 1980s and by bismuth subsalicylate starting in 2004.[57]

Research on eating disorders from the 16th to the 20th centuries suggests that during that time in history, pica was regarded more as a symptom of other disorders rather than its own specific disorder. Even today, what could be classified as pica behavior is a normative practice in some cultures as part of their beliefs, healing methods, or religious ceremonies.[8]

Prior to the elimination of the category of "feeding disorders in infancy and early childhood", which is where pica was classified, from the DSM-5, pica was primarily diagnosed in children.[50] However, since the removal of the category, psychiatrists have started to diagnose pica in people of all ages.[50]

The Glore Psychiatric Museum in Saint Joseph, Missouri has a 1910 exhibit with "an imaginative starburst arrangement of 1,446 buttons, screws, bolts, and nails that were eaten by a patient who died unexpectedly. They were only discovered during her autopsy."[58]

Animals

Unlike in humans, pica in dogs or cats may be a sign of immune-mediated hemolytic anemia, especially when it involves eating substances such as tile grout, concrete dust, and sand. Dogs exhibiting this form of pica should be tested for anemia with a complete blood count or at least hematocrit levels.[59][60] Although several hypotheses have been proposed by experts to explain pica in animals, insufficient evidence exists to prove or disprove any of them.[10] In addition to domestic cases, animal studies have helped scientists better understand pica and other disordered eating patterns. Animal Models of Eating Disorders highlights that eating disorders are often caused by a mix of environmental, genetic, and social factors, and studying animals can help isolate these causes. For example, researchers can separate abnormal eating patterns from changes in body weight to see how eating behavior alone affects health and brain function.[61]

Experimental studies have also explored treatment responses. One study found that pica-like behavior in rats caused by chemotherapy drugs was reduced after specific vagotomies, showing a biological connection between the brain, stomach, and eating behavior.[62] These findings help explain how pica and related eating behaviors can be both physical and psychological. All bodies are interconnected, all functions and processes in a body of any animal are affected by one another, through these experiments and observation we can infer how any eating disorder or specifically pica has a noticeable affect in all aspects of life.

Cultural and Real-Life Perspectives

Cultural research continues to show that pica is not only medical but also social. For example, a study in North-Central Nigeria found that pica among women is often shaped by cultural beliefs and community practices, rather than just psychological or nutritional causes.[63] Real-life cases, such as a 10-year-old boy who felt a strong, uncontrollable urge to eat fibers and described relief after doing so, demonstrate how pica can overlap with obsessive-compulsive behaviors.[64]

See also

References

  1. ^ "Pica". Merriam-Webster. Retrieved April 19, 2020.
  2. ^ OED ed. 3 via Apple Dictionary.
  3. ^ a b c d e f g h i "Feeding and Eating Disorders". Diagnostic and Statistical Manual of Mental Disorders. DSM Library. American Psychiatric Association. May 22, 2013. doi:10.1176/appi.books.9780890425596.dsm10. ISBN 978-0-89042-555-8 – via archive.org.
  4. ^ a b T. E. C. Jr. (October 1, 1969). "The origin of the word pica". Pediatrics. 44: 4 – via AAP.
  5. ^ a b c d Blinder BJ, Salama C (May 2008). "An update on pica: prevalence, contributing causes, and treatment". Psychiatric Times. 25 (6).
  6. ^ Singhi S, Singhi P, Adwani G (December 1981). "Role of Psychosocial Stress in the Cause of Pica". Clinical Pediatrics. 20 (12): 783–785. doi:10.1177/000992288102001205. PMID 7307412. S2CID 1129239.
  7. ^ a b López LB, Ortega Soler CR, de Portela ML (March 2004). "Pica during pregnancy: a frequently underestimated problem". Archivos Latinoamericanos de Nutricion. 54 (1): 17–24. PMID 15332352.
  8. ^ a b c d e Rose EA, Porcerelli JH, Neale AV (2000). "Pica: Common but commonly missed". The Journal of the American Board of Family Practice. 13 (5): 353–358. PMID 11001006.
  9. ^ Fabiani A, Dal Bo E, Di Bella S, Gabrielli M, Bologna A, Albert U, Sanson G (July 5, 2021). "Pica (Allotriophagy): An Underestimated Risk Factor for Severe Leptospirosis (Weil's Diseases)? Report of a Leptospira Septic Shock Successfully Managed with ECMO". Infectious Disease Reports. 13 (3): 619–626. doi:10.3390/idr13030058. ISSN 2036-7449. PMC 8293114. PMID 34287302.
  10. ^ a b "Pica: Why Pets Sometimes Eat Strange Objects". The Humane Society of the United States. Archived from the original on March 14, 2016. Retrieved July 20, 2019.
  11. ^ Bradshaw JW, Neville PF, Sawyer D (April 1, 1997). "Factors affecting pica in the domestic cat". Applied Animal Behaviour Science. Behavioural Problems of Small Animals. 52 (3): 373–379. doi:10.1016/S0168-1591(96)01136-7. ISSN 0168-1591.
  12. ^ Peter Sturmey, Michel Hersen (2012). Handbook of Evidence-Based Practice in Clinical Psychology, Child and Adolescent Disorders. John Wiley & Sons. p. 304. ISBN 978-0-470-33544-4.
  13. ^ "Acuphagia and Eating Metal". Psychology Today. Retrieved March 16, 2019.
  14. ^ a b Coleman AM (2015). A Dictionary of Psychology. Oxford University Press. p. 576. See Google books link.
  15. ^ Sturmey P, Hersen M (2012). Handbook of Evidence-Based Practice in Clinical Psychology, Child and Adolescent Disorders. John Wiley & Sons. p. 304. See Google books link.
  16. ^ Johnson BE, Stephens RL (1982). "Geomelophagia. An unusual pica in iron-deficiency anemia". The American Journal of Medicine. 73 (6): 931–2. doi:10.1016/0002-9343(82)90802-6. PMID 7148884.
  17. ^ Andrew M. Colman (2015). A Dictionary of Psychology. OUP Oxford. p. 576. ISBN 978-0-19-105784-7.
  18. ^ Somalwar A, Keyur Kishor Dave (March 2011). "Lithophagia: Pebbles in and Pebbles out" (PDF). Journal of the Association of Physicians of India. 59: 170. PMID 21751627. Archived from the original (PDF) on May 31, 2012. Retrieved July 22, 2012.
  19. ^ Gowda M, Patel BM, Preeti S, Chandrasekar M (2014). "An unusual case of xylophagia (paper-eating)". Industrial Psychiatry Journal. 23 (1): 65–7. doi:10.4103/0972-6748.144972. PMC 4261218. PMID 25535449.
  20. ^ a b Pica New York Times Health Guide
  21. ^ "Mental Health and Pica". WebMD. Retrieved March 16, 2019.
  22. ^ Spitzer, Robert L. Diagnostic and Statistical Manual of Mental Disorders: (DSM III). Cambridge: Univ. of Cambridge, 1986. Print.
  23. ^ a b c Miao D, Young SL, Golden CD (January 2015). "A meta-analysis of pica and micronutrient status". American Journal of Human Biology. 27 (1): 84–93. doi:10.1002/ajhb.22598. ISSN 1520-6300. PMC 4270917. PMID 25156147.
  24. ^ Gull WW (1874). "Anorexia nervosa (apepsia hysterica, anorexia hysterica)". Trans. Clin. Soc. Lond. 7 (5): 498–502. doi:10.1002/j.1550-8528.1997.tb00677.x. PMID 9385628.
  25. ^ Hergüner S, Ozyildirim I, Tanidir C (2008). "Is Pica an eating disorder or an obsessive–compulsive spectrum disorder?". Progress in Neuro-Psychopharmacology & Biological Psychiatry. 32 (8): 2010–1. doi:10.1016/j.pnpbp.2008.09.011. PMID 18848964. S2CID 207408405.
  26. ^ Frazzoli C, Pouokam GB, Mantovani A, Orisakwe OE (October 1, 2016). "Health risks from lost awareness of cultural behaviours rooted in traditional medicine: An insight in geophagy and mineral intake". Science of the Total Environment. 566–567: 1465–1471. Bibcode:2016ScTEn.566.1465F. doi:10.1016/j.scitotenv.2016.06.028. ISSN 0048-9697. PMID 27342642.
  27. ^ Gundacker C, Kutalek R, Glaunach R, Deweis C, Hengstschläger M, Prinz A (July 1, 2017). "Geophagy during pregnancy: Is there a health risk for infants?". Environmental Research. 156: 145–147. Bibcode:2017ER....156..145G. doi:10.1016/j.envres.2017.03.028. ISSN 0013-9351. PMID 28342960. S2CID 2661446.
  28. ^ Nyanza EC, Joseph M, Premji SS, Thomas DS, Mannion C (April 15, 2014). "Geophagy practices and the content of chemical elements in the soil eaten by pregnant women in artisanal and small scale gold mining communities in Tanzania". BMC Pregnancy and Childbirth. 14 (1): 144. doi:10.1186/1471-2393-14-144. ISSN 1471-2393. PMC 3997190. PMID 24731450.
  29. ^ Njiru H, Elchalal U, Paltiel O (July 1, 2011). "Geophagy During Pregnancy in Africa: A Literature Review". Obstetrical & Gynecological Survey. 66 (7): 452–459. doi:10.1097/OGX.0b013e318232a034. ISSN 0029-7828. PMID 21944157. S2CID 29431551.
  30. ^ Madziva C, Chinouya MJ (October 1, 2023). "African migrant women acquisition of clay for ingestion during pregnancy in London: a call for action". Public Health. 223: 110–116. doi:10.1016/j.puhe.2023.07.021. ISSN 0033-3506. PMID 37634450. S2CID 261189504.
  31. ^ Madziva C, Chinouya MJ (2020). "Clay Ingestion During Pregnancy Among Black African Women in a North London Borough: Understanding Cultural Meanings, Integrating Indigenous and Biomedical Knowledge Systems". Frontiers in Sociology. 5 20. doi:10.3389/fsoc.2020.00020. ISSN 2297-7775. PMC 8022624. PMID 33869429.
  32. ^ R. Kevin Grigsby, et al. (February 1999). "Chalk Eating in Middle Georgia: a Culture-Bound Syndrome of Pica?". Southern Medical Journal. 92 (2): 190–192. doi:10.1097/00007611-199902000-00005. PMID 10071665.
  33. ^ Franklin Kamtche (January 12, 2010). "Balengou: autour des mines" [Balengou: around the mines]. Le Jour (in French). Archived from the original on July 15, 2011. Retrieved March 1, 2010.
  34. ^ Marc Lallanilla (January 4, 2006). "Eating Dirt: It Might Be Good for You". ABC News. Retrieved November 30, 2020.
  35. ^ a b c d e Williams F, Gibbs S, Addo AS (November 2022). "The assessment and management of pica in people with intellectual disability". BJPsych Advances. 28 (6): 383–392. doi:10.1192/bja.2022.24. ISSN 2056-4678.
  36. ^ a b c d e "Pica: What It Is, Causes, Symptoms & Treatment". Cleveland Clinic. May 6, 2022.
  37. ^ a b c d e f g Al Nasser Y, Muco E, Alsaad AJ (2025), "Pica", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 30335275, retrieved September 3, 2025
  38. ^ Ganesan PR, Vasauskas AA (2023). "The Association Between Pica and Iron-Deficiency Anemia: A Scoping Review". Cureus. 15 (4) e37904. doi:10.7759/cureus.37904. ISSN 2168-8184. PMC 10199804. PMID 37220446.
  39. ^ Abu BA, Morrissey A, Wu Y, Castillo DA, Becker R, Wu T, Fiscella K, Gill S, Xiao J (January 3, 2025). "Pica practices, anemia, and oral health outcomes: a systemic review". BMC Oral Health. 25 (1): 13. doi:10.1186/s12903-024-05371-7. ISSN 1472-6831. PMC 11697756. PMID 39754099.
  40. ^ Hagopian LP, Rooker GW, Rolider NU (2011). "Identifying empirically supported treatments for pica in individuals with intellectual disabilities". Research in Developmental Disabilities. 32 (6): 2114–2120. doi:10.1016/j.ridd.2011.07.042. PMID 21862281.
  41. ^ Bhatia MS, Gupta R (May 11, 2007). "Pica responding to SSRI: An OCD spectrum disorder?". The World Journal of Biological Psychiatry. 10 (4–3): 936–8. doi:10.1080/15622970701308389. PMID 17853279. S2CID 30089547.
  42. ^ Tabaac BJ, Tabaac V (February 2015). "Pica patient, status post gastric bypass, improves with change in medication regimen". Therapeutic Advances in Psychopharmacology. 5 (1): 38–42. doi:10.1177/2045125314561221. ISSN 2045-1253. PMC 4315675. PMID 25653830.
  43. ^ Mehra A, Sharma N, Grover S (2018). "Pagophagia in a Female with Recurrent Depressive Disorder: A Case Report with Review of Literature" (PDF). Turk Psikiyatri Dergisi = Turkish Journal of Psychiatry. 29 (2): 143–145. PMID 30215844.
  44. ^ Fotoulaki M, Panagopoulou P, Efstratiou I, Nousia-Arvanitakis S (2007). "Pitfalls in the approach to pica". European Journal of Pediatrics. 166 (6): 623–4. doi:10.1007/s00431-006-0282-1. PMID 17008997. S2CID 1429977.
  45. ^ a b Fawcett EJ, Fawcett JM, Mazmanian D (June 2016). "A meta-analysis of the worldwide prevalence of pica during pregnancy and the postpartum period". International Journal of Gynaecology and Obstetrics. 133 (3): 277–283. doi:10.1016/j.ijgo.2015.10.012. ISSN 1879-3479. PMID 26892693. S2CID 205265004.
  46. ^ Ashworth M, Hirdes JP, Martin L (2009). "The social and recreational characteristics of adults with intellectual disability and pica living in institutions". Research in Developmental Disabilities. 30 (3): 512–20. doi:10.1016/j.ridd.2008.07.010. PMID 18789647.
  47. ^ Danford DE, Huber AM (1982). "Pica among mentally retarded adults". American Journal of Mental Deficiency. 87 (2): 141–6. PMID 7124824.
  48. ^ a b Hartmann AS, Becker AE, Hamptom C, Bryant-Waugh R (November 2012). "Pica and Rumination Disorder in DSM-5". Psychiatric Annals. 42 (11): 426–30. doi:10.3928/00485713-20121105-09.
  49. ^ a b c Chatoor I (2009). "Chapter 44: Feeding and eating disorders of infancy and early childhood". In Sadock BJ, Sadock VA, Ruiz P (eds.). Kaplan and Sadock's Comprehensive Textbook of Psychiatry (9th ed.). Lippincott, Williams & Wilkins. p. 3607. ISBN 978-0-7817-6899-3.
  50. ^ a b c Michalska A, Szejko N, Jakubczyk A, Wojnar M (2016). "Nonspecific eating disorders - a subjective review". Psychiatria Polska. 50 (3): 497–507. doi:10.12740/PP/59217. ISSN 2391-5854. PMID 27556109.
  51. ^ Lewis CT, Short C (1879). "pīca". A Latin Dictionary. Clarendon Press. Archived from the original on July 13, 2021 – via Perseus Project.
  52. ^ Thyer BA, Wodarski JS (2007). Social work in mental health: an evidence-based approach. John Wiley and Sons. pp. 133. ISBN 978-0-471-69304-8.
  53. ^ "Pica | Etymology, origin and meaning of pica by etymonline".
  54. ^ "Henry George Liddell, Robert Scott, A Greek-English Lexicon, κίσσα^".
  55. ^ "geophagy". Merriam-Webster Dictionary. Retrieved October 27, 2014.
  56. ^ Martin A (2013). Life Traces of the Georgia Coast: Revealing the Unseen Lives of Plants and Animals. Indiana University Press. p. 43. ISBN 978-0-253-00602-8.
  57. ^ Pray WS, Pray JJ (2005). "Diarrhea: Sweeping Changes in the OTC Market". US Pharmacist. 30 (1). Retrieved March 24, 2017.
  58. ^ "Glore Psychiatric Museum, St. Joseph, Missouri". Archived from the original on April 22, 2021.
  59. ^ Plunkett SJ (2000). Emergency Procedures for the Small Animal Veterinarian. Elsevier Health Sciences. p. 11. ISBN 978-0-7020-2487-0.
  60. ^ Feldman BF, Joseph G. Zinkl, Nemi Chand Jain, Oscar William Schalm (2000). Schalm's Veterinary Hematology. Blackwell Publishing. p. 506. ISBN 978-0-683-30692-7.
  61. ^ Kim SF (June 1, 2012). "Animal models of eating disorders". Neuroscience. 211: 2–12. doi:10.1016/j.neuroscience.2012.03.024. ISSN 1873-7544. PMC 3351502. PMID 22465439.
  62. ^ De Jonghe BC, Horn CC (March 2008). "Chemotherapy-induced pica and anorexia are reduced by common hepatic branch vagotomy in the rat". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 294 (3): R756 – R765. doi:10.1152/ajpregu.00820.2007. ISSN 0363-6119.
  63. ^ Uche AO, Oloyede DB, Aiyelabegan CJ (March 31, 2025). "PUBLIC PERCEPTION OF PICA PRACTICE AMONG WOMEN IN NORTH-CENTRAL NIGERIA". African Journal of Social and Behavioural Sciences. 15 (2). ISSN 2141-209X.
  64. ^ Hergüner S, Ozyildirim I, Tanidir C (December 12, 2008). "Is Pica an eating disorder or an obsessive-compulsive spectrum disorder?". Progress in Neuro-Psychopharmacology & Biological Psychiatry. 32 (8): 2010–2011. doi:10.1016/j.pnpbp.2008.09.011. ISSN 0278-5846. PMID 18848964.

Further reading

allikas: http://en.wikipedia.org/wiki/Glass_eater