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3 Epidemiology Research Unit, University of the West Indies, Kingston 7, Jamaica; 4 Institute of Psychiatry, London SE5 8AF, UK; and 5 Institute of Child Health, London WC1N 1EH, UK
* To whom correspondence should be addressed. E-mail: susan.walker{at}uwimona.edu.jm.
| ABSTRACT |
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| Introduction |
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Children hospitalized for severe malnutrition in early childhood have been reported to have problems with aggressive behavior (5), attention deficits (6), and poor social relationships at school age (7). Although stunted children have been found to have behavior changes in early childhood, such as less happiness and more apathy and fussiness (8), there has been little investigation of whether their later emotional and behavioral functioning is affected.
We conducted a prospective cohort study of stunted and nonstunted Jamaican children beginning at age 9–24 mo. In the first 2 y, the stunted children participated in a randomized trial of supplementation and psychosocial stimulation. Each treatment benefited concurrent development (2). Stimulation had sustained benefits to cognitive functioning at ages 7, 11, and 17 y (9–11), whereas benefits from supplementation were not sustained. Neither intervention affected teacher- and parent-reported behavior problems at age 11 y (12). There were no benefits of supplementation to psychological functioning at age 17 y; however, stimulation had significant benefits, including fewer symptoms of anxiety and depression and better self-esteem (13).
Stunted children who did not receive stimulation continued to have poorer levels of cognitive functioning than nonstunted children (11). Here, we compare emotional and behavioral outcomes of stunted participants with nonstunted participants at age 17–18 y. As stimulation had significant benefits to psychological functioning, we compared the nonstunted participants with the stunted participants according to whether they received stimulation. There are considerable data showing that many of the functions measured (symptoms of depression, self-esteem, attention deficit, and oppositional and antisocial behavior) are related to poverty; however, general anxiety is sometimes associated with better socioeconomic conditions (14). We therefore measured extensive socioeconomic variables to allow for any differences between the groups when assessing the effect of stunting.
| Participants and Methods |
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The children were reexamined at ages 7 and 11 y. To increase the power of comparisons between stunted and nonstunted groups, an additional 52 nonstunted children were studied from age 7 y. They had been identified in the original survey when they were aged 9–24 mo and fulfilled all inclusion criteria. They lived in the same neighborhoods as the study children and were comparable to the original group of nonstunted children in social background (9).
Follow-up at 17–18 y. Psychological functioning was assessed when participants were aged 17–18 y. The aim was to assess emotional and behavioral symptoms and no attempt was made to diagnose specific disorders. Written informed consent was obtained from the participants and their parents. Ethical approval for the study was given by the Ethics Committees of the University of the West Indies and the Institute of Child Health, University College London.
Psychological functioning. Self-esteem was assessed with the How I Think about Myself questionnaire (17), anxiety symptoms were assessed with the Manifest Anxiety (What I Think and Feel) Questionnaire (18), and depressive symptoms were assessed with the Short Mood and Feelings Questionnaire (19). Antisocial behavior was assessed with the Behavior and Activities Checklist (20). Questionnaires were administered in a private interview at our research unit. All were obtained by self report.
Although young people are considered valid informants for most behaviors by age 17 y, attention deficit and hyperactivity symptoms are exceptions. Therefore, the Conners' Parent Rating Scale (short form) (21) was administered to the mothers (or primary caregiver if not the mother) to obtain information on attention deficit. The Conners' Scale also provides scores for cognitive problems/inattention, hyperactivity, and oppositional behavior.
All questionnaires were piloted and reworded as necessary to ensure comprehension. This involved replacing words or short phrases not easily understood with others more familiar to the participants. For example, the item "often I feel sick in my stomach" was changed to "you often feel sick/upset in your belly." No items were omitted from any of the questionnaires. All questionnaires were interviewer administered; therefore, for 3 of the scales (How I Think about Myself, What I Think and Feel, and Short Mood and Feelings), which were written to allow self-administration, we changed portions of the questions from first- to second-person (i.e. "I felt ..." to "You felt...").
Test-retest reliabilities (intraclass correlation coefficient) after a 2-wk interval, in 18 nonstudy subjects recruited from schools attended by the study subjects, were
0.7 and internal consistency (Cronbach's
) ranged from 0.55 to 0.85 (Table 1). Participant interviews were administered by one interviewer and parent questionnaires by another interviewer. Interviewers were unaware of the participants' group. Inter-observer agreement with another trained interviewer in 23 interviews was
97% for all items.
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Statistical analysis.
Outcome variables were screened for normality and the depressive symptoms and antisocial behavior scales were normalized using square root transformations. Associations between participant characteristics and psychological outcomes were determined by Pearson's product-moment correlation coefficient (age, housing, mothers' PPVT) or Spearman rank correlation (hunger, occupation, and witnessing and victim of crime). Gender differences were determined by t test. An
of P < 0.05 was used to assess significance. Because stimulation but not supplementation had significant benefits on psychological functioning, to determine the effect of stunting, the nonstunted group was compared with the stunted children who had not participated in the stimulation program (nonstimulated stunted: control and supplement only groups) and with those who had received stimulation (stimulated stunted: stimulation only and stimulated and supplemented groups). Group was coded as 2 dummy variables to compare each of the stunted groups with the nonstunted group. The dummy variables were: nonstimulated stunted = 1, other groups = 0; and stimulated stunted = 1, other groups = 0. Our interest in this report is on the impact of early childhood stunting. We report the unadjusted effects of stunting followed by the effects after adjusting for possible confounders. In multiple regression analyses, participants' age, sex, and social background variables that either differed between stunted and nonstunted groups at follow-up or were correlated with the outcomes were offered stepwise before entering the 2 dummy variables for group. Social background variables offered in the analyses were hunger, housing score, mothers' PPVT and occupation, father present in the home, and whether the participants had witnessed or been a victim of violent crime in the past year.
| Results |
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Participant characteristics. The nonstunted children had higher birth weight (P < 0.001), height-for-age (P < 0.001), and better housing (P = 0.002) on enrollment than the stunted groups (Table 2). The nonstunted participants remained taller than the stunted groups (P < 0.001) at follow-up. The mothers/caregivers of the nonstunted group had better verbal scores than the combined stunted groups (P = 0.03). There were no other differences between the nonstunted and stunted groups in any measured social background variables. The nonstimulated stunted participants reported more hunger than the stimulated stunted group (P = 0.03).
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The analyses were repeated entering birth weight. Higher birth weight was associated with less anxiety (coefficient = –1.77, 95% CI = –3.52, –0.02; P = 0.05). The difference in anxiety between nonstunted and nonstimulated stunted participants remained significant (coefficient = 2.57, 95% CI = 0.47, 4.67; P = 0.02). Birth weight was not a significant predictor of any of the other outcomes.
The role of IQ. Most psychosocial problems are more common in children with low IQ (14) and we previously reported that the stunted children had lower IQ than the nonstunted children (11). IQ scores were significantly correlated with all the psychological scores. We therefore examined whether cognitive ability mediated the effect of stunting by repeating the multiple regressions entering IQ before the dummy variables for group. The change in the regression coefficients comparing the nonstimulated stunted group and the nonstunted group was tested using the method of Freedman and Schatzkin (22). The coefficients decreased (P < 0.05) for anxiety (24.8%), depressive symptoms (43%), and self-esteem (33.1%). The change in the regression coefficient for hyperactivity was not significant. The difference between stunted and nonstunted children in anxiety remained significant (P < 0.05), but the groups no longer differed in depressive symptoms or self-esteem.
| Discussion |
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A critical question is whether the association between early childhood stunting and poor psychological functioning in late adolescence is causal or whether stunting is a proxy for poor environments that independently affect psychological outcomes. The stunted and nonstunted children came from the same neighborhoods and we had measures of their socioeconomic status, maternal characteristics, and exposure to violence. Several of these measures were related to the outcomes, but after adjusting for their effects, significant differences remained between stunted and nonstunted participants, with effect sizes ranging from 0.37 SD for depressive symptoms to 0.51 SD for anxiety. The HOME score did not predict psychological functioning; however, we did not have this measure for the nonstunted participants enrolled at age 7 y. Therefore, the power of the analyses for the HOME score was less than for the other measures included. It thus remains possible that differences in the quality of the home environment, or residual confounding from unmeasured aspects of socioeconomic status, may contribute to differences between the nonstimulated stunted group and the nonstunted group. Nonetheless, it is likely that at least part of the differences in psychological functioning is due to undernutrition in the first 2 y of life. Increased internalizing problems were also found in children aged 11–14 y treated for iron deficiency anemia in infancy compared with nonanemic children (23), suggesting that psychological functioning may also be affected by specific nutrient deficiencies.
The stunted children had a more negative affect in early childhood (8) and were more inhibited at 9–10 y (24). Thus, differences in affect may have persisted since early childhood. The stunted participants also had higher conduct disorder at age 11 y (12) and the tendency to higher levels of oppositional behavior at age 17 y is consistent with this.
We cannot be certain of the mechanism whereby stunting is associated with poor psychological functioning. Animal research shows that early undernutrition can affect brain structure and function, leading to lasting cognitive and emotional effects (25). Thus, alterations to the brain as a result of childhood undernutrition could be 1 mechanism for the observed differences in psychological functioning. Lower IQ is a well-recognized risk factor for a range of child psychopathology (26). IQ was lower in the stunted participants, and when IQ was controlled for in the analyses, stunting was no longer significantly associated with depressive symptoms or self-esteem. It is possible that low IQ led to the children having lower self-esteem and more depressive symptoms. However, the stunted children had a more negative affect in early childhood (8). It is therefore also possible that stunting could have affected cognitive and psychological functioning concurrently.
Unlike the other behaviors that were more prevalent in the stunted children, hyperactivity was not affected by intervention, suggesting the effects may be difficult to reverse. In adequately nourished children, hyperactivity is associated with altered functional anatomy of several areas of the brain, including the frontal lobe and basal ganglia (27). It is possible that stunting in the first 2 y also affects these areas. Whereas hyperactivity is genetic in general populations, there is also substantial evidence for longer term effects of inadequacies in the early rearing environment on attention and hyperactivity (28).
Raised cortisol levels are associated with depression and anxiety in adequately nourished subjects (29,30). Alterations in the stress response were found in a sub-sample of the stunted children at 9–10 y of age (24) and could be another mechanism by which childhood undernutrition might affect later psychological functioning. We plan to investigate this possibility in the future.
We previously reported that an early childhood stimulation program had significant benefits to the stunted children's psychological functioning (13). We have shown here that the stunted children who received stimulation reported levels of anxiety, depressive symptoms, and self-esteem similar to those of the nonstunted participants. This is very encouraging and emphasizes the importance of early interventions. The only detectable remaining deficit in the stimulated stunted group was in hyperactive behavior.
There is some evidence of associations between growth in utero and adult psychological functioning. Exposure to famine in utero increased the risk of schizophrenia (31) and antisocial behavior (32), and birth weight was associated with psychological distress, depression, and suicidal behavior (33–35). In the present study, birth weight was related to anxiety but not to any other psychological outcomes; however, few participants had birth weights <2500 g. There is less information relating postnatal growth to later psychological functioning. In the UK, weight at 1 y was related to incidence of suicide (36) and weight gain from birth to 7 y was related to psychological distress (33).
A limitation to this study is that the instruments used have not been validated in Jamaica. However, the associations between the scores of the scales and socioeconomic background, gender, and IQ were theoretically sensible, the test retest reliability was good, and the internal reliability of the scales acceptable. We made minor modifications to the wording to facilitate better understanding by the participants and gave the questionnaires by interview because the participants' reading ability was not always adequate. We did not remove any items and it is likely that the external validity of the revised instruments would be similar to that of the original scales; however, it would be desirable to have this confirmed with clinical assessments in the future.
We used a conservative approach to examine differences between the nonstunted and stunted groups, including as covariates any variables that were correlated with the outcomes even if they did not differ among the groups. To achieve the most parsimonious model, we included covariates using stepwise analyses. Thus, although the associations found between covariates and the outcomes are plausible and consistent with the literature, it is possible that some of these may be due to chance.
Maternal depression has been shown to be associated with poor growth and undernutrition in children (37,38). Maternal psychological status, including depression and anxiety, is also an important contributor to poor adolescent mental health (39,40). We did not measure maternal affect or depression; however, it is unlikely to have been the main cause of stunting in this study. In a subsequent study of undernourished and adequately nourished Jamaican children (41), mothers of undernourished children were more likely to report depressive symptoms. However, depression did not predict the likelihood of the child being undernourished once socioeconomic factors were considered.
In conclusion, we have previously shown that stunting in early childhood is associated with deficits in cognition and educational achievement in late adolescence (11). This study provides probably the first evidence, to our knowledge, linking stunting and poor psychological functioning, extending the range of disadvantages attributed to early childhood stunting. Deficits were seen in emotional outcomes and in some aspects of behavior. Poor psychological functioning is likely to affect the participants' quality of life and may influence their social competence and parenting. The etiology of stunting may vary between settings with low or high prevalence. Further studies of the association between stunting and later psychological functioning are needed, particularly from countries where early childhood stunting is more prevalent than in Jamaica. Considering that 151 mil-lion children <5 y old in developing countries are estimated to be stunted (42), the findings further emphasize that stunting in early childhood is a serious public health concern.
| ACKNOWLEDGMENTS |
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| FOOTNOTES |
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2 Author disclosures: S. P. Walker, S. M. Chang, C. A. Powell, E. Simonoff, and S. M. Grantham-McGregor, no conflicts of interest. ![]()
Manuscript received 14 March 2007. Initial review completed 10 May 2007. Revision accepted 29 August 2007.
| LITERATURE CITED |
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1. United Nations System SCN. Fifth report on the world nutrition situation. Geneva: SCN; 2004.
2. Grantham-McGregor SM, Powell CA, Walker SP, Himes JH. Nutritional supplementation, psychosocial stimulation, and mental development of stunted children: the Jamaican Study. Lancet. 1991;338:1–5.[Medline]
3. Daniels MC, Adair LS. Growth in young Filipino children predicts schooling trajectories through high school. J Nutr. 2004;134:1439–46.
4. Martorell R, Rivera J, Kaplowitz H, Pollitt E. Long-term consequences of growth retardation during early childhood. In: Hernandez M, Argente J, eds. Human growth: basic and clinical aspects. Amsterdam: Elsevier Science Publishers B.V.;1992. p. 143–9.
5. Galler JR, Ramsey F. A follow-up study of the influence of early malnutrition on development: behavior at home and at school. J Am Acad Child Adolesc Psychiatry. 1989;28:254–61.[Medline]
6. Richardson SA, Birch HG, Grabie E, Yoder K. The behavior of children in school who were severely malnourished in the first two years of life. J Health Soc Behav. 1972;13:276–84.[Medline]
7. Richardson SA, Birch HG, Ragbeer C. The behaviour of children at home who were severely malnourished in the first 2 years of life. J Biosoc Sci. 1975;7:255–67.[Medline]
8. Gardner JM, Grantham-McGregor SM, Himes J, Chang S. Behaviour and development of stunted and nonstunted Jamaican children. J Child Psychol Psychiatry. 1999;40:819–27.[Medline]
9. Grantham-McGregor SM, Walker SP, Chang SM, Powell CA. Effects of early childhood supplementation with and without stimulation on later development in stunted Jamaican children. Am J Clin Nutr. 1997;66:247–53.
10. Walker SP, Grantham-McGregor SM, Powell CA, Chang SM. Effects of growth restriction in early childhood on growth, IQ, and cognition at age 11 to 12 years and the benefits of nutritional supplementation and psychosocial stimulation. J Pediatr. 2000;137:36–41.[Medline]
11. Walker SP, Chang SM, Powell CA, Grantham-McGregor SM. Effects of early childhood psychosocial stimulation and nutritional supplementation on cognition and education in growth-stunted Jamaican children: prospective cohort study. Lancet. 2005;366:1804–7.[Medline]
12. Chang SM, Walker SP, Grantham-McGregor S, Powell CA. Early childhood stunting and later behaviour and school achievement. J Child Psychol Psychiatry. 2002;43:775–83.[Medline]
13. Walker SP, Chang SM, Powell CA, Simonoff E, Grantham-McGregor SM. Effects of psychosocial stimulation and dietary supplementation in early childhood on psychosocial functioning in late adolescence: follow-up of randomised controlled trial. BMJ. 2006;333:472.
14. Goodman R, Scott S. Child psychiatry. Oxford: Blackwell Science; 1997.
15. Hamil P, Drizd T, Johnson C, Reed R, Roche A. Growth curves for children, birth-18 years, 165 (DHEW # 78–1650) Vital and Health Statistics Series 11. Hyatsville (MD): National Center for Health Statistics; 1977.
16. Walker SP, Powell CA, Grantham-McGregor SM, Himes JH, Chang SM. Nutritional supplementation, psychosocial stimulation, and growth of stunted children: the Jamaican study. Am J Clin Nutr. 1991;54:642–8.
17. Warr P, Jackson P. Self-esteem and unemployment among young workers. Trav Hum. 1983;46:355–66.
18. Reynolds CR, Richmond BO. What I think and feel: a revised measure of children's manifest anxiety. J Abnorm Child Psychol. 1978;6:271–80.[Medline]
19. Costello EJ, Angold A. Scales to assess child and adolescent depression: checklists, screens, and nets. J Am Acad Child Adolesc Psychiatry. 1988;27:726–37.[Medline]
20. Olweus D. Persistence and prevalence in the study of antisocial behaviour: definitions and measurement. In: Klein MW, ed. Cross-national research in self reported crime and delinquency. Dordrecht (The Netherlands): Kluwer; 1989.
21. Conners CK, Sitarenios G, Parker JD, Epstein JN. The revised Conners' Parent Rating Scale (CPRS-R): factor structure, reliability, and criterion validity. J Abnorm Child Psychol. 1998;26:257–68.[Medline]
22. MacKinnon DP, Lockwood CM, Hoffman JM, West SG, Sheets V. A comparison of methods to test mediation and other intervening variable effects. Psychol Methods. 2002;7:83–104.[Medline]
23. Lozoff B, Jimenez E, Hagen J, Mollen E, Wolf AW. Poorer behavioral and developmental outcome more than 10 years after treatment for iron deficiency in infancy. Pediatrics. 2000;105:E51.[Medline]
24. Fernald LC, Grantham-McGregor SM. Stress response in school-age children who have been growth retarded since early childhood. Am J Clin Nutr. 1998;68:691–8.[Abstract]
25. Strupp BJ, Levitsky DA. Enduring cognitive effects of early malnutrition: a theoretical reappraisal. J Nutr. 1995;125:S2221–32.[Medline]
26. Rutter M. The role of cognition in child development and disorder. Br J Med Psychol. 1987;60:1–16.[Medline]
27. Swanson J, Casellanos X, Frith U, Pennington B, Shafer D, Spitzer M, Spence MA. Developmental psychopathology. Dev Sci. 2001;4:345–58.
28. Croft C, Beckett C, Rutter M, Castle J, Colvert E, Groothues C, Hawkins A, Kreppner J, Stevens SE, et al. Early adolescent outcomes of institutionally-deprived and non-deprived adoptees. II: language as a protective factor and a vulnerable outcome. J Child Psychol Psychiatry. 2007;48:31–44.[Medline]
29. de Kloet ER, Vreugdenhil E, Oitzl MS, Joels M. Brain corticosteroid receptor balance in health and disease. Endocr Rev. 1998;19:269–301.
30. Michael RP, Gibbons JL. Interrelationships between the endocrine system and neuropsychiatry. Int Rev Neurobiol. 1963;5:243–302.[Medline]
31. Susser ES, Lin SP. Schizophrenia after prenatal exposure to the Dutch Hunger Winter of 1944–1945. Arch Gen Psychiatry. 1992;49:983–8.
32. Neugebauer R, Hoek HW, Susser E. Prenatal exposure to wartime famine and development of antisocial personality disorder in early adulthood. JAMA. 1999;282:455–62.
33. Cheung YB, Khoo KS, Karlberg J, Machin D. Association between psychological symptoms in adults and growth in early life: longitudinal follow up study. BMJ. 2002;325:749.
34. Gale CR, Martyn CN. Birth weight and later risk of depression in a national birth cohort. Br J Psychiatry. 2004;184:28–33.
35. Mittendorfer-Rutz E, Rasmussen F, Wasserman D. Restricted fetal growth and adverse maternal psychosocial and socioeconomic conditions as risk factors for suicidal behaviour of offspring: a cohort study. Lancet. 2004;364:1135–40.[Medline]
36. Barker DJ, Osmond C, Rodin I, Fall CH, Winter PD. Low weight gain in infancy and suicide in adult life. BMJ. 1995;311:1203.
37. Harpham T, Huttly S, De Silva MJ, Abramsky T. Maternal mental health and child nutritional status in four developing countries. J Epidemiol Community Health. 2005;59:1060–4.
38. Patel V, DeSouza N, Rodrigues M. Postnatal depression and infant growth and development in low income countries: a cohort study from Goa, India. Arch Dis Child. 2003;88:34–7.
39. Beardslee WR, Versage EM, Gladstone TR. Children of affectively ill parents: a review of the past 10 years. J Am Acad Child Adolesc Psychiatry. 1998;37:1134–41.[Medline]
40. Hammen C, Brennan PA. Severity, chronicity, and timing of maternal depression and risk for adolescent offspring diagnoses in a community sample. Arch Gen Psychiatry. 2003;60:253–8.
41. Baker-Henningham H, Powell C, Walker S, Grantham-McGregor S. Mothers of undernourished Jamaican children have poorer psychosocial functioning and this is associated with stimulation provided in the home. Eur J Clin Nutr. 2003;57:786–92.[Medline]
42. Grantham-McGregor S, Cheung YB, Cueto S, Glewwe P, Richter L, Strupp B. Developmental potential in the first 5 years for children in developing countries. Lancet. 2007;369:60–70.[Medline]
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