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Bought in the act: How prevalent is compulsive buying?

Although shopping is a necessity in modern life, it is also a leisure activity and a form of entertainment with a rewarding value for some people. However, as I have noted in a number of my previous blogs, when taken to the extreme, shopping (or buying) can be a harmful and destructive activity for a minority of individuals. The consequences of compulsive buying behaviour (CBB) are often underestimated.

For instance, CBB can result in (i) large debts, (ii) inability to meet payments, (iii) criticism from partners, friends and acquaintances, (iv) legal and financial consequences, (v) criminal legal problems, and (vi) guilt. Furthermore, individuals with CBB often describe an increasing level of urge or anxiety that can only be alleviated and lead to a sense of completion when a purchase is made. Research has demonstrated that compulsive buying is a frequent disorder in a small minority of shopping mall visitors and is associated with important and robust indicators of psychopathology such as psychiatric distress, borderline personality disorder, and substance abuse. Compared to non-compulsive buyers, compulsive buyers are over twice as likely to abuse substances, have any mood or anxiety disorder, and three times more likely to develop eating disorder than non-compulsive buyers. However, most of these findings are based on a small number of studies, all of which have sampling limitations.

Despite many studies highlighting the severe negative consequences that compulsive buying can lead to, the latest (fifth) edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) did not include compulsive buying disorder due to insufficient research in the field. Therefore, individuals with the condition are classified within the residual category of “Unspecified disruptive, impulse-control, and conduct disorders”. Diagnostic criteria elsewhere include (i) maladaptive preoccupation with buying or shopping, or maladaptive buying or shopping impulses; (ii) generation of marked distress by the buying preoccupations, impulses or behaviours, which are time consuming, significantly interfere with social or occupational functioning or result in financial problems; and (iii) lack of restriction of the excessive buying or shopping behaviour to periods of hypomania or mania.

The age of onset for CBB appears to be in the late teens or early twenties, although some studies have reported a later mean age of 30 years. There is also a lack of consensus relating to gender differences. Most clinical studies report that women are much more likely to become compulsive buyers than men, but not all surveys have found significant differences in buying tendencies between men and women. Cultural mechanisms have been proposed to recognize the fact that CBB mainly occurs among individuals living in developed countries. Elements reported as being necessary for the development of CBB include the presence of a market-based economy, the availability of a wide variety of goods, disposable income, and significant leisure time. For these reasons, most working in the area agree that CBB is unlikely to occur in poorly developed countries, except among the wealthy elite.

Given this background, Aniko Maraz, Zsolt Demetrovics and I recently carried out a meta-analytic review that was published in the journal Addiction using all the empirical data concerning the prevalence of compulsive buying in non-clinical populations. We attempted to estimate a pooled prevalence of compulsive buying behaviour (CBB) in different populations across the world where studies have been carried out. We also examined the effect of age, gender, geographical location of the study.

Our initial literature search identified 638 publications. We then excluded case studies (n=23), reviews or theoretical works (n=192), studies involving data from clinical samples (n=244), qualitative studies (n=26), studies that used a compulsive buying scale to determine shopping severity but didn’t report a prevalence rate (n=73), studies written in a foreign language (n=15), dissertations and conference abstracts (n=7), studies written in a foreign language (n=15), small studies with a sample size of below 145 participants (n=16), and studies involving adolescents (n=2). This left 40 studies that met the inclusion criteria for the review. We then extracted sample mean age, proportion of females (in %), the study’s geographical location, and the screening instrument used to assess CBB, and the reported prevalence estimate of CBB.

The 40 relevant studies identified reported 49 different prevalence rate estimates for 32,333 participants. We then divided the data into four sub-samples: adult representative, adult non-representative, university student and shopping-specific. The mean prevalence of compulsive buying was 4.9% in adult representative samples [10,102 participants], 12.3% in adult non-representative samples [3,929 participants], 8.3% in university student samples [14,947 participants] and 16.2% in shopping-specific samples [4,686 participants]. Unsurprisingly, the highest prevalence rates were among shopping-specific samples.

We noted that the heterogeneity in prevalence rates of CBB may be because of the lack of consensus regarding the definition of compulsive buying. Studies used different measures to assess CBB, each having a different conceptual background. Most definitions include cognitive-affective indicators as well as maladaptive behavioural consequences when defining the disorder (e.g., debts). The screening instruments used across studies differed in indicators of financial consequences (e.g., credit card use, debts, loan etc.) and are subject to differences according to countries, sub-cultures and/or age groups.

Another problem we identified was that measures used to assess CBB didn’t explicitly distinguish current and lifetime assessment of CBB. Prevalence rates assessed with an instrument that assessed lifetime prevalence report 1.6 times higher rates on average than those that assessed current prevalence. We also observed that non-representative samples (e.g., adults, university students, shoppers) tended to recruit younger participants who were more likely to be female than representative studies. However, we also noted that the mean age of the sample and the proportion of males and females did not have a reliable effect on the prevalence estimates.

Being of a younger age was predictive of CBB according to individual study results and also according to the regression analysis that we carried out in the representative samples. However, it remains open as to whether compulsive buying tendency decreases with age or this difference reflects generational differences. If the latter was the case, then the prevalence of compulsive buying behaviour is expected to increase in the future. We also found some evidence for increasing rates of CBB in Germany and in Spain, but longitudinal studies are needed to clarify this.

In relation to data collection, estimates from the United States (18 out of 49) were over-represented compared to countries other than the USA, although there was no difference in the reported estimates between the U.S. and non-U.S. countries. However, it is difficult to draw reliable conclusions regarding the cultural variance of CBB given that adult representative estimates are only available from the USA, Spain, Germany and Hungary.

The fact that compulsive buying behaviour is a relatively common disorder with severe consequences for a minority of individuals should not be overlooked. It appears that approximately one in 20 individuals suffer from CBB at some point in their lives and that being young and female are associated with a higher risk of CBB. High heterogeneity is likely to be the result of methodological variability within studies, such as assessment screens with different time frames and conceptual background. We concluded that future studies should therefore think carefully about how to conceptualise the disorder and to clearly separate out current versus lifetime prevalence in the samples used.

Dr. Mark Griffiths, Professor of Behavioural Addiction, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Please note : This article was co-written with Aniko Maraz and Zsolt Demetrovics (Institute of Psychology, Eötvös Loránd University, Budapest, Hungary)

Further reading

Alemis, M. C., & Yap, K. (2013). The role of negative urgency impulsivity and financial management practices in compulsive buying. Australian Journal of Psychology, 65(4), 224-231.

Andreassen, C.S., Griffiths, M.D., Pallesen, S., Bilder, R.M., Torsheim, T. Aboujaoude, E.N. (2015). The Bergen Shopping Addiction Scale: Reliability and validity of a brief screening test. Frontiers in Psychology, 6:1374. doi: 10.3389/fpsyg.2015.01374.

Basu, B., Basu, S., & Basu, J. (2011). Compulsive buying: an overlooked entity. Journal of the Indian Medical Association, 109(8), 582-585.

Black, D.W., Shaw, M., McCormick, B., Bayless, J.D., Allena, J. (2012). Neuropsychological performance, impulsivity, ADHD symptoms, and novelty seeking in compulsive buying disorder. Psychiatry Research, 200, 581–587.

Black, D. W. (2007). A review of compulsive buying disorder. World Psychiatry, 6, 14-18.

Davenport, K., Houston, J.E., Griffiths, M.D. (2012). Excessive eating and compulsive buying behaviours in women: An empirical pilot study examining reward sensitivity, anxiety, impulsivity, self-esteem and social desirability. International Journal of Mental Health and Addiction, 10, 474–489.

Dittmar, H., Long, K. & Bond, R. (2007). When a better self is only a button click away: Associations between materialistic values, emotional and identity-related buying motives, and compulsive buying tendency online. Journal of Social and Clinical Psychology, 26, 334-361.

Duroy, D., Gorse, P., & Lejoyeux, M. (2014). Characteristics of online compulsive buying in Parisian students. Addictive Behaviors, 39, 1827-1830.

Frost, R.A., Tolin, D.F., Steketee, G., Fitch, K.E., Selbo-Bruns, A. (2009). Excessive acquisition in hoarding, Journal of Anxiety Disorders, 23, 632-639.

Guo, Z., Cai, Y. (2011). Exploring the antecedents of compulsive buying tendency among adolescents in China and Thailand: A consumer socialization perspective. African Journal of Business Management, 5(24), 10198-10209.

Harvanko, A., Lust, K., Odlaug, B. L., Schreiber, L., Derbyshire, K., Christenson, G., & Grant, J. E. (2013). Prevalence and characteristics of compulsive buying in college students. Psychiatry Research, 210(3), 1079-1085.

Jung, J., & Yi, S. (2013). Assessment of heterogeneity of compulsive buyers based on affective antecedents of buying lapses. Addiction Research and Theory, 22, 37-48.

Koran, L.M., Faber, R.J., Aboujaoude, M.A., Large, M.D., Serpe, R.T. (2006). Estimated prevalence of compulsive buying behavior in the United States. American Journal of Psychiatry, 163, 1806-1812.

Kukar-Kinney, M., Ridgway, N. M., & Monroe, K. B. (2012). The role of price in the behavior and purchase decisions of compulsive buyers. Journal of Retailing, 88(1), 63-71.

Lejoyeux, M., Weinstein, A. (2010). Compulsive buying. American Journal of Drug and Alcohol Abuse, 36 (5), 248–253.

Maraz, A., Griffiths, M. D., Demetrovics, Z. (2015). The prevalence of compulsive buying in nonclinical populations: a systematic review and meta-analysis. Addiction, doi:10.1111/add.13223.

Mikołajczak-Degrauwe, K., & Brengman, M. (2014). The influence of advertising on compulsive buying – The role of persuasion knowledge. Journal of Behavioral Addictions3(1), 65–73.

Mueller, A., Mitchell, J. E., Peterson, L. A., Faber, R. J., Steffen, K. J., Crosby, R. D., & Claes, L. (2011). Depression, materialism, and excessive Internet use in relation to compulsive buying. Comprehensive Psychiatry, 52(4), 420-424.

Tommasi, M., & Busonera, A. (2012). Validation of three compulsive buying scales on an Italian sample 1. Psychological Reports, 111(3), 831-844.

Weinstein, A., Maraz, A., Griffiths, M.D., Lejoyeaux, M. & Demetrovics, Z. (in press). Shopping addiction and compulsive buying: Features and characteristics of addiction. In V. Preedy (Ed.), The Neuropathology Of Drug Addictions And Substance Misuse. London: Academic Press.

Bog standard: A brief look at toilet tissue eating

In previous blogs I have looked at pica (i.e., the eating of non-nutritive items or substances) and subtypes of pica such as geophagia (eating of soil, mud, clay, etc.), pagophagia (eating of ice), acuphagia (eating of metal), and coprophagia (eating of faeces). It wasn’t until I started to research on specific sub-types of pica, that I discovered how many different types of non-food substances had been identified in the academic and clinical literature. For instance, Dr. V.J. Louw and colleagues provided a long list in a 2007 issue of the South African Medical Journal including cravings for the heads of burnt matches (cautopyreiophagia), cigarettes and cigarette ashes, paper, starch (amylophagia), crayons, cardboard, stones (lithophagia), mothballs, hair (trichophagia), egg shells, foam rubber, aspirin, coins, vinyl gloves, popcorn (arabositophagia), and baking powder. Most of these are generally thought to be harmless but as Louw and colleagues note, a wide range of medical problems have been documented:

“These include abdominal problems (sometimes necessitating surgery), hypokalaemia, hyperkalaemia, dental injury, napthalene poisoning (in pica for toilet air-freshener blocks), phosphorus poisoning (in pica for burnt matches), peritoneal mesothelioma (geophagia of asbestos-rich soil), mercury poisoning (in paper pica), lead poisoning (in dried paint pica and geophagia), and a pre-eclampsia-like syndrome (baking powder pica)”.

In the clinical literature, the eating of paper has been occasionally documented (although anecdotal evidence suggests this is fairly common and I remember doing it myself as a child). A recent review paper on pica by Dr. Silvestre Frenk and colleagues in the Mexican journal Boletín Médico del Hospital Infantil de México highlighted dozens of pica-subtypes and created many new names for various pica sub-types. They proposed that people who eat paper display ‘papirophagia’ (in fact if you type ‘papirphagia’ into Google, you only get one hit – the paper by Silvestre and colleagues – although this blog may make it two!). Eating paper is not thought to be particularly harmful although I did find a case of mercury poisoning because of ‘paper pica’ (as the authors – Dr. F. Olynk and Dr. D. Sharpe – called it) in a 1982 issue of the New England Journal of Medicine.

One sub-type of papirophagia is the eating of toilet paper. As far as I am aware, there is only one case study in the literature and this was published back in 1981, Dr. J. Chisholm Jr. and Dr. H. Martín in the Journal of the National Medical Association. They described the case of a 37-year old black woman with an “unusually bizarre craving” for toilet tissue paper. The authors reported that:

“[The] woman was referred for evaluation of disturbed smell and loss of taste for over one year. These were associated with chronic fatigue and listlessness. During this same period of time, she rather embarrassedly admitted to an overwhelming desire to eat toilet tissue. Frequently, she would awaken at night and dash to her bathroom to eat toilet tissue. No other type(s) of pica were admitted. In addition, she gave a long history of menorrhagia and frequently passed vaginal blood clots during her menses. Her libido was normal and there was no history of poor wound healing, skin or mucous membrane lesions, or intestinal symptoms. Her dietary history suggested a high carbohydrate diet, and due to a mild exogenous obesity she intermittently resorted to a vegan-like diet that included beans and various seeds”

A variety of medical tests were carried out and she was diagnosed with combined iron and zinc deficiency. She was treated with iron and zinc tablets and within a week, both her taste and smell had returned, and her energy levels greatly improved. Zinc deficiencies can lead to a wide variety of clinical disorders including loss of small and taste, anorexia, dwarfism (i.e., growth retardation), impaired wound healing, and geophagia. The woman’s (sometimes) vegan diet may have been to blame for her zinc deficiency as the authors noted that:

Although vegetables contain zinc, vegans should be made aware that zinc from plant sources is not readily absorbed because naturally occurring phytates, particularly high in beans and seeds, reduce zinc gastrointestinal absorption. Carbohydrates are very poor sources of zinc. Chronic iron deficiency secondary to chronic menorrhagia accounts well for the anemia, fatigue, and unusual pica for toilet tissue noted in this patient”.

Paper pica has occasionally been mentioned in other academic papers although details have typically been limited. For instance, a 1995 paper in the journal Birth by Dr. N.R. Cooksey on three cases of pica in pregnancy reported that one of the women chewed non-perfumed blue toilet paper during the first trimester of her pregnancy (and was forced by her mother to stop). There was also a 2003 paper published by Dr. Dumaguing in the Journal of Geriatric Psychiatry and Neurology examining pica in mentally ill geriatrics. One of the cases mentioned was a 76-year old patient that not only ingested their medication (an emollient cream for arthritis) but was also recorded eating toilet paper, napkins, Styrofoam cups, crayons, and other patients’ medications.

A more recent 2008 paper by Dr. Sera Young and her colleagues in the journal PLoS ONE, critically reviewed procedures and guidelines for interviews and sample collection in relation to pica substances. In describing the protocols involved, they referred to paper pica in the questions that should be asked:

“What is the local name, brand name, or type of pica substance desired or consumed? This will help others to know if this substance has already been studied and assist interested researchers in obtaining subsequent samples at a later date. Furthermore, different manufactured products may contain different materials, e.g. Crayola chalkboard chalk contains slightly different ingredients from other brands. Similarly, the consequences of toilet tissue paper consumption are different from those of eating pages of a novel; information would be lost if the substance was simply described as paper. For these reasons, the substance consumed should be described in as much detail and as accurately as possible”.

Personally (and based on anecdotal evidence), I think that papirophagia is not overly rare (especially among children – although I admit this may be more out of curiosity that craving) but the clinical literature suggests that it is a fairly rare disorder found amongst distinct sub-groups (pregnant women, the mentally ill). Given the fact that for most people eating paper would not cause any problems, this would provide the main reason why so few cases end up seeking medical, clinical, and/or psychological help.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Chisholm Jr, J. C., & Martín, H. I. (1981). Hypozincemia, ageusia, dysosmia, and toilet tissue pica. Journal of the National Medical Association, 73(2), 163-164.

Cooksey, N.R. (1995). Pica and olfactory craving of pregnancy: How deep are the secrets? Birth, 22, 129-137.

Dumaguing, N.I., Singh, I., Sethi, M., & Devanand, D.P. (2003). Pica in the geriatric mentally ill: unrelenting and potentially fatal. Journal of Geriatric Psychiatry and Neurology, 16, 189-191.

Frenk, S., Faure, M.A., Nieto, S. & Olivares, Z. (2013). Pica. Boletín Médico del Hospital Infantil de México, 70(1), 55-61

Louw, V.J., Du Preez, P., Malan, A., Van Deventer, L., Van Wyk, D., & Joubert, G. (2007). Pica and food craving in adults with iron deficiency in Bloemfontein, South Africa. South African Medical Journal, 97, 1069-1071.

Olynyk, F., & Sharpe, D. H. (1982). Mercury poisoning in paper pica. The New England Journal of Medicine, 306, 1056 -1057.

Young, S.L., Wilson, M.J., Miller, D., Hillier, S. (2008). Toward a comprehensive approach to the collection and analysis of pica substances, with emphasis on geophagic materials. PLoS ONE, 3(9), e3147. doi:10.1371/journal.pone.0003147

A pining for dining: A brief overview of Gourmand Syndrome

In 2005, an article in the May 8th issue of the New York Times magazine reported the case of an unnamed European political journalist who had a stroke that caused some damage to the right frontal lobe in his brain. The journalist made a full recovery but experienced an unexpected side effect – he developed an unusual passion for gourmet food (that he didn’t have prior to his stroke).  He capitalized on his strange new behaviour and became a food columnist. Similarly, a 2011 article in the Huffington Post reported the story of Kevin Pearce, a snowboarder who sustained right hemispheric brain damage following an accident that nearly killed him. Waking up from a coma he developed a craving for basil pesto (something that he never did prior to his accident). Both of these cases are examples of a rare disorder that has been named Gourmand Syndrome, a strange behaviour first written about (clinically and academically) in the mid-1990s. Gourmand Syndrome basically comprises individuals becoming totally preoccupied and obsessed with food and ‘fine dining’.

This rare (and benign) condition only seems to occur in people who have sustained brain injuries involving the right frontal lobe and was first described (and named) by neuropsychologist Dr. Marianne Regard and neurologist Dr. Theodor Landis in a 1997 issue of the journal Neurology (one of only two empirical papers on the topic). The authors noted that hyper-orality is part of other conditions such as the Kluver-Bucy syndrome that occurs in patients with bilateral mesial temporal lesions (and which I examined in a previous blog).

Regard and Landid described the cases of two individuals who both had partial damage to the right anterior cerebral hemisphere of the brain. The first case was the political journalist briefly mentioned at the start of this article. He became totally preoccupied with gourmet food and continued after he had been discharged from hospital. The second case that Regard and Landis wrote about was a businessman who (following a stroke) also developed a passion for gourmet food. However, his preoccupation with gourmet food was part of a wider disturbance of impulse control as he also made repeated sexual advances towards the female nursing staff at the hospital he was in. (Interestingly, a later 2003 study by Regard and Landis on 21 pathological gamblers – and published in the journal Cognitive and Behavioral Neuropsychology – reported that 38% of them [n=8] were reported to have Gourmand Syndrome, again suggesting that these impulsive behaviours are highly inter-linked).

Having named this type of behaviour as Gourmand Sydrome, Regard and Landis then conducted a prospective study examining the frequency and the clinical and anatomical correlates of the syndrome. Over a three-year period, and using a self-constructed checklist, they carried out 723 neuropsychological examinations of patients with known (or strongly suspected) cerebral lesions. The specific criteria for Gourmand syndrome were: (i) the presence of a significant change in a person’s eating habits (i.e. preoccupation with the preparation and eating of fine-quality food), (ii) the onset of which was associated with a single cerebral lesion in the absence of other medical or social conditions, and (iii) previous eating disorders; or other neurological or psychiatric illness. A total of 36 people fulfilled the criteria for Gourmand Syndrome (5%).

Of those identified fulfilling the three criteria, 94% of them (n=34) appeared to have right hemisphere damage in the brain (in particular, the right anterior part of the brain involving basal ganglia, cortical areas, and limbic structures). Most of the individuals’ symptoms were caused by tumours (although there were other causes including focal seizures, head trauma [with focal concussion], haemorrhage, and cerebrovascular accidents). The authors concluded that:

“Most patients with the ‘gourmand syndrome’ had clinical and anatomical evidence of a unilateral right-sided lesion, mainly involving anterior cortico-limbicregions. The strong clinical-anatomical correlation suggests that gourmand eating can represent a neurological sign of diagnostic value. The eating behavior does not correspond to any known category of eating disorders. At most, it could be classified as a benign, non-disabling form of hyperphagia, but with a specific preference for fine food”

A later case study of Gourmand Syndrome by Dr. Mary Kurian and her Swiss colleagues was published in the journal Epilepsy and Behavior. They reported the case of a 10-year-old boy with epilepsy (and who had hemispheric brain damage (i.e., “right temporoparietal hemorrhagic lesion”). As with previous adult cases, he developed Gourmand Syndrome and experienced a significant change in his eating habits, or as the authors put it, an “abnormal preoccupation with the preparation and eating of fine-quality food…without any previous history of eating disorders or psychiatric illness”. More specifically, the boy’s parent’s noticed that he began to avoid eating at fast-food restaurants and would only eat or cook the finest foods. The authors argued that their case study confirmed previous observations relating to the importance of the right cerebral hemisphere in disturbed eating habits, not just in Gourmand Syndrome but eating disorders such as anorexia and obesity.

Both of the published empirical papers noted that Gourmand Syndrome includes an obsessive component along with other behavioural consequences typically associated with addiction (e.g., cravings, preoccupation, salience, etc.). They also notes that one-third of the 36 patients identified in their prospective study had symptoms of mania (e.g., aggression, diminished impulse control, disinhibition, affective lability). In recent a review of Gourmand Syndrome by trainee psychiatrist Alexandros Chatziagorakis in the Neuropsychiatry News concluded that:

“Owing to the rarity of further articles and reports of Gourmand syndrome, its diagnostic significance is yet to be proven. It would be worth using Regard [and] Landis checklist during neuropsychological assessment of neurological patients to establish its frequency and its clinical and anatomical correlates. At the same time, it would be worth performing a psychiatric assessment to determine whether Gourmand syndrome presents in the context of an already defined psychiatric syndrome such as mania. This will tell us whether Gourmand syndrome has indeed a diagnostic value as a neurological or even neuropsychiatric sign”.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Chatziagorakis, A. (2012). Gourmand Syndrome. Neuropsychiatry News, 5 (Spring), 23-24.

Holt, T. (2005). Of two minds. New York Times (Magazine), May 8. Located at:

Huffington Post (2011). The Gourmand Syndrome: Brain Damage Can Trigger Food Obsession, Huffington Post, October 9. Located at:

Kurian, M., Schmitt-Mechelke, T., Korff, C., Delavelle, J., Landis, T. & Seeck, M. (2008). “Gourmand syndrome” in a child with pharmacoresistant epilepsy. Epilepsy and Behavior, 13, 413-415.

Regard, M., Knoch, D., Gütling, E. & Landis, T (2003). Brain damage and addictive behavior: A neuropsychological and electroencephalogram investigation with pathologic gamblers. Cognitive and Behavioral Psychology, 16, 47-53.

Regard, M. & Landis, T (1997). ‘Gourmand syndrome’: Eating passion associated with right anterior lesions. Neurology, 48, 1185-1190.

Uher, R. & Treasure, J. (2005). Brain lesions and eating disorders. Journal of Neurology, Neurosurgery and Psychiatry, 76, 852–7.

Pica boom? A beginner’s guide to pica

Pica is an eating disorder that has been documented in the psychological literature for hundreds of years and refers to a behaviour in which individuals eat non-nutritive items or substances (such as coal, hair and wood). The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) defines pica as “the persistent eating of nonnutritive substances for a period of at least one month, without an association with an aversion to food”. Therefore, one-off instances of eating non-nutritious items would not constitute pica. Children who occasionally eat items like crayons are rarely diagnosed as having pica. Pica comes from a Latin word for the magpie bird (known for its strange eating behaviours).

The prevalence rates of pica depend on which patient populations have been studied. Prevalence estimates are also skewed by the fact that many people suffering from pica are embarrassed about the behaviour and may not tell anyone and/or seek medial treatment. However, it is well established that pica is more prevalent in children, pregnant women, adults from lower socioeconomic classes, and children with developmental disabilities (such as autism). The incidence of pica is also higher amongst those suffering from family-related stress. Although pica can be a symptom of anaemia (i.e., iron deficiency) and other chemical imbalances, research has shown it is actually more common among those who have normal iron levels.

Prevalence rates of pica have range anywhere between 0.02% and 74% depending on the study and population studied. For instance, studies have reported pica prevalence rates of:

  • 0.02% in Danish pregnant women
  • 8% in US black pregnant women (pagophagia)
  • 9% in Saudi Arabian pregnant women
  • 26.5% in Tanzanian pregnant women (geophagia)
  • 31% of Californian Mexican pregnant women
  • 44% of Mexican pregnant women
  • 50% of Nigerian pregnant women
  • 74% in Kenyan pregnant women
  • 44% in French anaemic patients (vs. 9% matched controls)
  • 64% in Turkish anaemic patients (vs. 17% controls)
  • 22%-26% in mentally retarded adults
  • 34% in sickle cell disease patients

The Danish figure from a study led by Dr Tina Mikkelsen (University of Southern Denmark) is likely to be the most accurate as it was carried out on a sample of 100,000 pregnant Danish women and only 14 of the total sample reported that they had pica. The authors concluded that in privileged populations, pica is more a myth than a reality.

Despite increased research in the area, there has been no definitive explanation as to why some people consume such substances as hair (trichophagia), ice (pagophagia – which I briefly examined in a previous blog), soil/clay (geophagia), wood (xylophagia), stones (lithophagia), glass (hyalophagia), plumbophagia (lead paint chips), or laundry (uncooked) starch (amylophagia). Dr. Ella Lacey (Southern Illinois University) also listed many other non-food substances that pica sufferers may eat that don’t have specific names such as those people who eat paper, balloons, grass, soap, cotton wool, and cigarette butts. Pica is a widespread practice throughout Africa and India. It has also been reported in Australia, Canada, Israel, Iran, Uganda, Jamaica and various European countries. A recent review on pica led by Dr Sera Young (University of California, USA) noted that geophagia is the most common type of pica described in the psychological and medical literature. They also noted that:

  • Geophagics frequently eat other non-food stuffs.
  • Those who eat more manufactured substances say they use them as a replacement for earth, either because the desired soil is unavailable or socially unacceptable
  • Bar the eating of ice, most pica substances are absorptive in the dry state and all easily absorb moisture.
  • Pica substances are typically craved with great intensity or ‘‘devouring passion’’

A variety of conditions are known to cause some types of pica including mineral deficiencies, hookworm infection (parasitic infection in the small intestine), coeliac disease (an autoimmune disorder of the small intestine) and Kleine-Levin Syndrome (also known as Sleeping Beauty Syndrome, a neurological disorder characterized by recurring periods of excessive amounts of sleeping and eating). Interestingly, there are culture-specific cases where pica is not related to psychopathological disorders or deficiencies. For instance, black women in Georgia (USA) are known to eat kaolin (white dirt that is actually a clay mineral) – a so-called “culture-bound syndrome” (i.e., a recognizable combination of psychiatric and somatic symptoms that are only within a specific culture or society).

Some pica type disorders may be part of a wider psychiatric condition (such as schizophrenia) and/or may be part of a sexual paraphilia such as the small numbers of people who engage in coprophagia (eating faces) as part of coprophilia and people who engage in urophagia (drinking urine) as part of urophilia. If the primary focus for eating the item or substance was sexual, it would be more likely diagnosed as a sexual paraphila rather than pica. However, many of those with pica claim to love the taste, texture and/or smell of the things they eat. Some studies have suggested an association between pica and addictive behaviors. Others suggest pica is on the obsessive-compulsive disorder (OCD) spectrum of diseases. For instance, a study based on pica case studies by Dr Dan Stein and colleagues (a the University of Stellenbosch, South Africa) came to the conclusion that (based on their case studies), pica may be a symptom of OCD, and that pica may be phenomenologically reminiscent of an impulse control disorder.

For many people, pica is not dangerous but for some there may be complications including (i) parasitic infections (such as geophagics eating soil or copraphagics eating faeces), (ii) internal bodily obstruction (e.g., such as tricophagics getting hair stuck in their intestines), (iii) toxic reactions (e.g., such as autistic children getting lead poisoning from eating painted plaster), (iv) excessive caloric intake (such as that occurring with starch cravings), (v) dental injuries and infections, and (vi) nutritional deficiencies.

As Dr. Lacey concluded: Pica appears to be a complex behavior that requires deliberate study rather than application of ex post facto single cause theories. Although such theories may motivate any given study of pica, it should be apparent that any single cause model will likely offer only a limited explanation of such diverse practices as have been described in the literature through case reports,’ research studies, and literature ‘reviews of various clinical and applied disciplines”

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

al-Kanhal, M.A., & Bani, I.A. (1995). Food habits during pregnancy among Saudi women. International Journal for Vitamin and Nutrition Research, 65, 206-210.

Ashworth, M., Hirdes, J.P. & Martin, L. (2008). The social and recreational characteristics of adults with intellectual disability and pica living in institutions. Research in Developmental Disabilities, 30, 512-520.

Danford, D.E. & Huber, A.M. (1982). Pica among mentally retarded adults. American Journal of Mental Deficiency, 87, 141-146.

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