Development and Psychopathology, 13 (2001), 611–628 Copyright 2001 Cambridge University Press Printed in the United States of America
Salivary cortisol levels in children adopted from Romanian orphanages
MEGAN R. GUNNAR,a SARA J. MORISON,b KIM CHISHOLM,c MICHELLE SCHUDERd
AND
a c
University of Minnesota; bCentre for Community Health and Health Evaluation Research; St. Francis Xavier University; and dHarvard University
Abstract Six and a half years after adoption, 6- to 12-year-old children reared in Romanian orphanages for more than 8 months in their first years of life (RO, n = 18) had higher cortisol levels over the daytime hours than did early adopted (EA, ≤ 4 months of age, n = 15) and Canadian born (CB, n = 27) children. The effect was marked, with 22% of the RO children exhibiting cortisol levels averaged over the day that exceeded the mean plus 2 SD of the EA and CB levels. Furthermore, the longer beyond 8 months that the RO children remained institutionalized the higher their cortisol levels. Cortisol levels for EA children did not differ in any respect from those of CB comparison children. This latter finding reduces but does not eliminate concerns that the results could be due to prenatal effects or birth family characteristics associated with orphanage placement. Neither age at cortisol sampling nor low IQ measured earlier appeared to explain the findings. Because the conditions in Romanian orphanages at the time these children were adopted were characterized by multiple risk factors, including gross privation of basic needs and exposure to infectious agents, the factor(s) that produced the increase in cortisol production cannot be determined. Nor could we determine whether these results reflected effects on the limbic–hypothalamic–pituitary– adrenal axis directly or were mediated by differences in parent–child interactions or family stress occasion by behavioral problems associated with prolonged orphanage care in this sample.
Throughout this century, developmental science has hotly debated whether young children deprived of stimulation by virtue of institutional rearing would be necessarily and permanently affected (Rutter, 1981). Based on This research was supported by a grant from the MacArthur Foundation. Our thanks to Charles Nelson, Thomas Boyce, and David Kupfer for their support and encouragement of this work. Much thanks is due to Elinor Ames, who facilitated the cortisol follow-up study, and to Lianne Fisher, who helped merge the Simon Fraser Team’s data set with the cortisol data set. The research was also supported by an Independent Scientist Award to the first author by the National Institute of Mental Health (MH00946). Thanks are also due to Mary Carlson and Felton Earls, who first encouraged us to work with orphanage-reared children, and to Ronald Barr, who graciously stored the samples at his laboratory in Montreal. Finally, our deep appreciation is due to the families of the children in this report who took on the task of collecting multiple saliva samples and completing health and diary information over several days.
studies in the 1960s and 1970s, dire predictions of irrevocable damage gave way to less extreme positions. Some children did appear to be permanently affected, but others recovered to normal functioning once placed in families. Until recently, it has been difficult to isolate the impact of early adversity because few children who suffered extreme deprivation and neglect in their first years subsequently moved into the type of enriching environments that might allow them a chance at recovery. Furthermore, when such children could be found, the length of time spent in deprived conditions was typically confounded with child characteristics (Verhulst, Althaus, & Versluis–Den Bieman, 1990a, 1990b, 1992). Address correspondence and reprint requests to: Dr. Megan R. Gunnar, Institute of Child Development, 51 East River Road, University of Minnesota, Minneapolis, MN 55455; E-mail:
[email protected].
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The fall of the Romanian dictator, Nicolae Ceaus¸escu, in December of 1989 offered developmental science a chance to return to these early experience questions (Rutter, 1998). Ceaus¸escu’s program for population growth resulted in upward of 65,000 abandoned children reared in state-run institutions under the most bleak and deprived conditions imaginable (Kaler & Freeman, 1994). In the months following the demise of his regime, prospective parents journeyed to Romania to adopt these children. From the early months of 1990 until June of 1991, when the Romanian government declared a moratorium on international adoption, thousands of children left Romania for homes in Western Europe and North America. Nearly all of the children were under the age of 5 years. Some were adopted at birth, others were adopted from families, but most were adopted after spending nearly all their early lives in institutions. Severe, global privation describes these children’s institutional experience: periods of malnutrition, poor medical care, high pathogen load, lack of sensory and motor stimulation, and a life devoid of emotional and social relationships (Rutter, 1998). In addition to several studies of convenience samples (e.g., Benoit, Jocelyn, Moddermann, & Embree, 1996; Groze & Ileana, 1996), two epidemiological studies recently have been published. One study in the United Kingdom examined a stratified, random sample adopted under the age of 42 months (Castle, Groothues, Bredenkamp, Beckett, O’Connor, Rutter, & ERA Study Team, 1999; O’Connor, Bredenkamp, & Rutter, 1999; Rutter, 1998). The other study in British Columbia, Canada, conducted by a research group from Simon Fraser University examined all of the orphanage-reared Romanian children adopted by families in the province (Ames, 1997; Chisholm, 1998; Fisher, Ames, Chisholm, & Savoie, 1997; Morison, Ames, & Chisholm, 1995; Morison & Ellwood, 2000). Behavior was the focus in both of these studies. Researchers found that, for the most part, children adopted before 6 months of age developed normally in both cognitive and social domains. Children adopted later made less certain recoveries. Several years postadoption
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many of these children scored well within the normal range on standardized tests of cognitive functioning and exhibited few behavioral or emotional problems. Nonetheless, some exhibited persistent cognitive deficits, insecure and often atypical attachment patterns, and clinically significant behavior problems. The likelihood of continued problems tended to increase with the duration of institutional experience. In none of these studies were physiological measures beyond height and weight obtained. Indeed, few studies of children reared in orphanages have ever assessed the physiological impact of early privation (e.g., see review of early deprivation studies, Rutter, 1981). This is true despite evidence of psychosocial dwarfism in orphanage-reared children and early onset puberty in some orphanage-reared girls (Johnson, 2000; Proos, Hofvander, & Turvermo, 1991; Rutter, 1998). While children show remarkable catch-up in height after adoption, often they remain shorter than other children (Johnson, 2000). Indeed, it is now recognized that neglect can suppress the growth of the long bones (Albanese, Hamill, Jones, Skuse, Matthews, & Stanhope, 1994; Gohlke, Khadilkar, Skuse, & Stanhope, 1998; Skuse, Albanese, Stanhope, Gilmour, & Voss, 1996). Both of these phenomena are potential reflections of early experiences impacting the development of neuroendocrine functioning. This may, in part, reflect the impact of chronic stress during institutionalization operating through effects on the limbic–hypothalamic– pituitary–adrenocortical (LHPA) system. In particular, corticotropin releasing hormone (CRH) and peripheral glucocorticoid (i.e., cortisol) are known to operate on the growth hormone system and on the production of growth factors in ways that suppress growth (Johnson, Kamilaris, Chrousos, & Gold, 1992). This reflects the role of the LHPA system in inhibiting future-oriented developmental processes under conditions that threaten survival. The impact of deprivation on neuroendocrine activity has been the focus of much of the research in rodents and nonhuman primates. Beginning decades ago, this work has dealt largely with the LHPA system (e.g., Levine & Thoman, 1970). The LHPA axis is
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involved in restoring homeostasis and facilitating adaptation to real or imagined threats to survival (de Kloet, Vreugdenhil, Oitzl, & Joels, 1998). Neurons in the paraventricular region of the hypothalamus express CRH and other cosecretogogues that stimulate the anterior pituitary to release adrenocorticotropic hormone (ACTH). ACTH travels through circulation to affect activity of the adrenal cortex resulting in the production and release of glucocorticoids (predominantly cortisol in humans). Basal levels of cortisol follow a daily or circadian rhythm mediated, in part, through the activity of mineralocorticoid receptors (MRs) in the hippocampus. Elevations in cortisol over baseline levels are contained, in part, through the activity of glucocorticoid receptors (GRs) in the hippocampus, as well GRs at other levels of the LHPA axis. Alterations in the balance of MRs and GRs are believed to play a role both in setting basal cortisol levels and in the individual’s capacity to contain stress-induced elevations in cortisol. There are a number of reasons to expect that orphanage care might alter activity of the LHPA system. Activity of the LHPA axis is affected by exposure to repeated or chronic stressors in ways hypothesized to contribute to negative emotionality and affective disorders (Rosen & Schulkin, 1998). Early adverse experiences are believed to be especially important in this regard (Heim, Owen, Plotsky, & Nemeroff, 1997). Gross privation characterized the conditions in Romanian orphanages for children adopted in 1990 and 1991 (e.g., Rutter, 1998). In addition to the lack of developmentally appropriate social and physical stimulation, food was scare, hygiene was poor, pathogen load was high, and it is likely that some of the children were physically and sexually abused (Frank, Klass, Earls, & Eisenberg, 1996). All of these conditions might influence activity of the LHPA axis. For example, Fernald and Grantham– McGregor (1998) have shown that children who experienced childhood growth retardation under the age of 2 years several years later had higher baseline cortisol levels than did other children drawn from the same neighborhoods. De Bellis, Baum, Birmaher, Keshavan, Eccard, Boring, Jenkins, and Ryan
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(1999) have shown that school-aged children with posttraumatic stress disorder (PTSD) due to physical or sexual abuse when they were preschoolers had higher 24-hr integrated urinary cortisol and epinephrine levels under ambulatory conditions than did children without a history of abuse. They also described pathways through which elevated cortisol and catecholamines could impair brain development. These data would all predict that orphanagereared children would have elevated cortisol levels. Animal studies also show long-term impact of early experiences on activity of the LHPA system. In animals, depriving infants of adequate maternal stimulation increases responsivity of the axis to stressors later in life (Caldji, Tannenbaum, Sharma, Francis, Plotsky, & Meaney, 1998; Levine, 1994; Meaney, Diorio, Francis, Widdowson, La Plante, Caldji, Sharma, Seckl, & Plotsky, 1996; Meaney, O’Donnell, Viau, Bhatnagar, Sarrieau, Smythe, Shanks, & Walker, 1993; Plotsky & Meaney, 1993; Sutanto, Rosenfeld, de Kloet, & Levine, 1996). And again, in animals, it has been shown that administering an endotoxin that causes high fever early in life produces effects on the LHPA axis that mimic those of maternal deprivation (Shanks, Laroque, & Meaney, 1995). Although manipulations of the pup during the first 2 weeks of life rarely result in elevated basal activity of the LHPA system, when privation is severe enough to cause growth retardation (Gilles, Schultz, & Baram, 1996) or when social and sensory privation is implemented in the 3rd week and extends into the late juvenile period (Sanchez, Aguado, Sanchez–Toscano, & Saphier, 1998) chronic elevations in basal activity have been noted. Early experiences in nonhuman primates also appear to affect the development of the LHPA axis. Rhesus monkeys raised under depriving conditions on cloth surrogates or only with peers exhibit larger and more prolonged elevations in cortisol to stressful stimulation (Higley, Suomi, & Linnoila, 1992). Disturbing mother–infant interaction by making maternal foraging demands unpredictable has also been shown to lead to increases in CRH levels measured when the offspring are adults (Coplan, Andrews, Owens, Friedman, Gor-
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man, & Nemeroff, 1996). Thus, the gross privation of young children in orphanage settings, including lack of stimulation, lack of social relations, malnutrition, high pathogen load, and increased likelihood of physical and sexual abuse all would predict increases in cortisol levels. To date, however, the only published study of cortisol levels in orphanage-reared children found only modest support for the prediction of elevated cortisol concentrations (Carlson, Dragomir, Earls, Farrell, Macovei, Nystrom, & Sparling, 1995; Carlson & Earls, 1997). This study was conducted on 2-yearolds living in an infant home in Romania and examined ambulatory basal cortisol levels at three points during the day, near wakeup, at noon before lunch, and in the late afternoon or evening. Overall, the children exhibited marked physical growth retardation and cognitive and motor delays. Nonetheless, Carlson found that ambulatory salivary cortisol levels were only slightly higher in these children as compared to ambulatory cortisol levels in family-reared Romanian 2-year-olds. More striking was the pattern of cortisol production over the day. For the family-reared children, as expected, cortisol levels were highest in the early morning and declined across the day. For the institutionally reared children, peak cortisol levels were sometimes noted at noon, with few children exhibiting the expected decline in cortisol over the hours between early morning and later afternoon or early evening. Furthermore, Carlson and Earls (1997) reported that noon levels correlated positively with delays in cognitive functioning. Thus, the Carlson et al. (1995) findings suggest that orphanage-rearing disturbs the normal diurnal pattern of cortisol production, but does not produce markedly elevated cortisol concentrations. The present study was designed to use a methodology similar to the Carlson et al. (1995) study. Cortisol was sampled under ambulatory conditions near the time of awakening, at noon, and in the evening as the children went about their normal daily routine. The opportunity to conduct this study was the result of a collaboration with the research team at Simon Fraser University who had
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conducted the study of Romanian children adopted into British Columbia (Ames, 1997; Chisholm, 1998; Fisher et al., 1997; Morison et al., 1995; Morison & Ellwood, 2000). Several years after their second assessment of the children, the families were asked to collect saliva samples for cortisol assessment on several days as the children went about their normal activities. The groups examined reflected the design developed by the Simon Fraser team. They had followed all of the Romanian orphanage (RO) children (n = 46) adopted after 8 months of orphanage experience by families in British Columbia. To provide a comparison sample, they used the records of four hospitals in the Vancouver area to identify age and gender matched Canadian children reared in their birth families. Then after phone interviews with these families, they identified and recruited Canadian born (CB) children who matched the RO children not only with regard to age and gender but also in other family characteristics, particularly maternal education. Finally, they also recruited an early adopted (EA, n = 29) group who were Romanian children adopted at or near birth ( .40) were noted for wakeup, noon, or evening values. Because of the wide range in age at sampling, however, age was covaried in several of the analyses described below. Parents collected saliva samples on 3 days, 15–30 min after the child woke up and before breakfast (“wakeup”), before lunch and preferably between 11 a.m. and 1 p.m. (“noon”), and within 30 min of bedtime and preferably between 8 and 9 p.m. (“evening”). They were asked to select days when nothing particularly
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exciting or unusual was scheduled and to eliminate milk-based products and products with caffeine in the hour prior to sampling. Parents recorded the time of sampling. Although there were variations between families in sampling times within the windows we allowed, within families the timing of sampling was highly stable across days (r’s > .80 for wakeup, noon, and evening sampling times) and thus were averaged to examine time-ofday differences between groups. No significant differences were noted. As shown in Table 1, wakeup sampling averaged between 8: 28 and 8:44 a.m. among groups. Noon sampling averaged between 12:00 and 12:34 p.m. among groups. With the exception of one RO child who was consistently sampled at 4 p.m., evening sampling averaged between 8:15 and 8:49 p.m. among groups. Analyses were computed with and without the child sampled at 4 p.m. As results did not differ, to preserve power this child’s data were retained in the sample. Including this child, cortisol values were not correlated with time of day during any sampling period (n = 60, r’s ranged from −.21 to −.06, ns). A few of the children were missing one or two of the three samples requested at each time of day, or the samples provided had too little saliva to analyze or cortisol concentrations that were so high as to indicate a nonphysiological concentration (see below). Overall, the complete protocols with usable data were available for 91% of the wakeup samples, 85% of the noon samples, and 88% of the evening samples. Only two children had more than one missing value at any time point (one EA child at noon and one RO child in the evening). By group, of all of the samples requested in the protocol 3% were missing for the RO children, 6% for the EA children, and 4% for the CB children. To stimulate saliva flow, children chewed a piece of original flavor Trident sugarless gum for about 1 min and then spat through a 2-in. plastic straw into a vial. These procedures do not to alter cortisol concentrations (Schwartz, Granger, Susman, Gunnar, & Laird, 1998). The vial was tightly capped and stored in the family’s refrigerator. When all
6.6 (6.2–7.2) 6.8 (6.4–7.4) 8.37 (1.24) 12.57 (0.17) 20.33 (0.47)
6.7 (6.1–7.7) 8.55 (7.6–11.8) 8.3 (0.78) 12.46 (0.13) 20.25 (1.10)
Early Adopted (N = 15)
20.81 (0.96)
12.38 (0.08)
8.74 (0.65)
7.9 (7.0–9.8)
NA
Canadian Born (N = 27)
Note: NA, not applicable; EA, early adopted; CB, Canadian born; RO, Romanian orphanage.
Years in adoptive home at cortisol sampling (mean and range) Age at cortisol sampling in years (mean and range) Time of wakeup sampling (mean and SD) Time of noon sampling (mean and SD) Time of evening sampling (mean and SD)
Romanian Orphanage (N = 18)
Table 1. Descriptive characteristics related to salivary cortisol sampling
Bonferoni NA EA < CB < RO NA NA NA
Significance and F Test ns, F (1, 31) = 1.5 p < .01, F (2, 57) = 21.7 ns, F (2, 57) = 1.5 ns, F (2, 57) = 0.57 ns, F (2, 57) = 2.22
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samples were complete, they were mailed to a laboratory in Canada for storage at −20°C. These procedures have been shown to have no effect on cortisol values (Clements & Parker, 1998). When salivary collection for the study was completed, the saliva samples were carried on dry ice by courier to the endocrine laboratory in the United States where they were assayed. These procedures precluded the need for separate customs clearances for each set of samples. Samples were assayed in duplicate using a modification of the CIBA Magic Cortisol Assay (Kirschbaum, Strasburger, Jammers, & Hellhammer, 1989). Samples were assayed in duplicate with all samples from a subject in the same assay batch to prevent interassay variation from obscuring patterns of daily cortisol production. Assay batches were constructed so that group differences would not be a reflection of interassay variation. This assay returns values down to .02 µg/dl. The values were scanned for ones that appeared physiologically improbable (i.e., >4.0 µg/dl). Inter- and intraassay coefficients of variation were 13.10 and 5.31. Distributions were examined for skew and kurtosis. As is often the case for cortisol, distributions were positively skewed (measures of skew, >1.0; measure of kurtosis, >1.0). The values were therefore log10 transformed prior to analysis.
Health and daily questionnaire Parents completed a daily questionnaire where they recorded the child’s bedtime, wake time, meal times, and sampling times. Parents also noted whether the child was showing any symptoms of being ill (i.e., runny nose, sneezing) and recorded any medications taken that day. Parents were asked to avoid sampling if the child had a fever. All daily diaries indicated the children were in good health at the time of sampling. On a separate form, parents recorded whether the child was diagnosed with a clinical condition or was taking psychotropic or steroid medication. As noted earlier, six children were removed from the analyses because of medications. (Note that the main analyses were also
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computed including these children. Inclusion or exclusion of the children on psychotropic medications did not alter any of the conclusions. These data are available from the authors on request.)
Previously collected data Once the cortisol data were assayed, they were merged with some of the behavioral data previously collected from these children. The variables examined in this report were age at adoption, months of institutional care, maternal education and child IQ assessed using the Stanford Binet IV, and the classification by the Simon Fraser group of children with three or four serious problems (low IQ, atypical attachment, stereotyped behavior, clinical levels of behavior problems). Collection of these data and description of the classification are described in previous publications (Ames, 1997; Chisholm, 1998; Fisher et al., 1997; Morison et al., 1995; Morison & Ellwood, 2000). The average time between the behavioral testing and cortisol sampling for the three groups was as follows: RO, M = 3.6 years (SD = 5 months); EA, M = 2.2 years (SD = 4 months); and CB, M = 2.6 years (SD = 7 months). The differences among groups in time between behavioral and cortisol sampling reflected the age of the children when the cortisol project was inaugurated. The behavioral testing on the last of the EA children was just being completed when the cortisol study began, and we were able to request cortisol measures close to when the EA children turned 6 years of age. In contrast, the behavioral testing on the RO and CB children was already completed and the children were over 6 years old when the cortisol project began. Given several years had transpired, we do not report on cortisol associations with most of these measures. We did, however, examine IQ as low cognitive functioning might reflect general neurological impairment and confound interpretation of the cortisol results. Not all children had been administered the Stanford Binet IV in the original sample. The IQ measure was available for 17 RO, 14 EA, and 21 CB children we studied.
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Results Characteristics of the sample We first examined the characteristics of this sample to provide a context in which to interpret the salivary cortisol results (see Table 2). The median age at adoptive placement for the RO children was 18 months, with a range of 9–68 months. The median time spent in institutional care was 17 months, with a range of 9–48 months. Eleven of the 18 RO children had been in institutional care continuously prior to adoption, 5 had spent 3 months or less with their families prior to institutionalization, while 1 child had spent 20 months with his family. At adoptive placement this latter child had been in institutional care for 28 months. (Note that when the data were analyzed without this child, none of the results described below differed in their statistical significance.) The median time spent in institutional care was 2 months for the EA children. Six of the 15 were placed within 1 or 2 weeks of birth, while 9 spent more than 1 month in institutional care prior to adoption. Parents of 55 of the children provided data on the children’s weight, while 53 provided data on height. As shown in Table 2, EA and CB groups averaged close to the 50th percentile for age on both height and weight. Weight was close to the 50th percentile for the RO children; however, height was lower. The mean differences were not statistically significant. However, when we examined the percentage of children with heights below the 20th percentile, we noted that 40% of the RO children had heights within this range, compared to 7% of the EA and 13% of the CB children, χ2 (2) = 6.4, p < .05. Cortisol data Substantial day-to-day variability is typically reported for ambulatory cortisol measures (Smyth, Ockenfels, Gorin, Catley, Porter, Kirschbaum, Hellhammer, & Stone, 1997). We therefore averaged the measures across days within time periods (wakeup, noon, evening) prior to analysis. All available samples per child were used to compute these mea-
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sures. To examine the rank order stability of these samples, Pearson correlations were computed within time of day. The average of the three correlations was less than r = .25 for both the wakeup and noon time points but was r = .45 for the evening time point. Because we were using the three samples as, in a sense, items on a cortisol scale at each time point, we also computed Cronbach alphas to determine how closely the items cohered or reflected the averaged values at each time point. The Cronbach alphas for the wakeup and noon averages were modest (α = .45 and .46, respectively), while that for the evening average was good (α = .73). Thus both analyses converged on the conclusion that the evening measures were most stable across days for the children and most reliably reflected an individual child’s cortisol levels. This led us to view the evening measures as the most useful in analyses comparing children within groups (e.g., correlations with other measures). For the wakeup and noon values we would need to rely on averaging over children within group to reduce error, and thus these measures might usefully contribute only to group level comparisons (e.g., ANOVAs). We then examined the relations between group and wakeup, noon, and evening cortisol averages using a repeated measures analysis of variance (Table 3). The main effect of group was significant, F (2, 57) = 4.39, p < .02, as was the effect of time of day, F (2, 114) = 245.4, p < .001. The group by time interaction was not significant (F < 1.0). As can be seen in Table 3, cortisol was high near wakeup for all groups and decreased over the day. To examine the main effect of group more closely, given that the Group × Time of day interaction was not significant, we standardized the values within time of day and averaged to compute a daily average cortisol (DAC) measure. This measure was subjected to Bonferoni post hoc testing. The results showed that RO children had significantly higher DAC than did either EA or CB children (p’s < .05). EA and CB children did not differ significantly. The EA group was included to help control for potential differences between children who might be placed in orphanages so that the duration of orphan-
2.0 (0.5–4) 2.0 (0.5–4) 15.3 (12–20) 48.6 (33.5) 53.6 (26.9) 104.1 (82–126)
18.0 (9–68) 17.0 (9–48) 13.9 (12–18) 50.8 (31.8) 36.9 (28.2) 87.1 (65–110)
Early Adopted (N = 15) NA NA
Canadian Born (N = 27)
106.7 (89–123)
50.6 (31.9)
14.6 (12–20) 57.9 (34.1)
Note: NA, not applicable; EA, early adopted; RO, Romanian orphanage; CB, Canadian born.
Age at adoption (median and range) Months of institutional experience (median and range) Maternal education (mean and SD) Weight percentile at cortisol assessment (mean and SD) Height percentile at cortisol assessment (mean and SD) Stanford Binet II (Simon Fraser group) (mean and range)
Romanian Orphanage (N = 18)
Bonferoni EA < RO EA < RO NA NA NA RO < EA, RO < CB
Significance p < .001, F (1, 31) = 30.4 p < .001, F (1, 31) = 49.2 ns, F (2, 53) = 1.5 ns, F (2, 52) = 0.7 ns, F (2, 50) = 1.5 p < .01, F (2, 41) = 12.0
Table 2. Descriptive characteristics potentially affecting interpretation of group differences in salivary cortisol levels
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Table 3. Means (and standard deviations) for cortisol (µg/dl) by group Groups
N
Wakeup
Noon
Evening
Romanian orphanage Early adopted Canadian born
18 15 27
.80a (.18) .68 (.18) .68 (.18)
.35 (.16) .26 (.17) .28 (.14)
.16 (.31) .10 (.26) .10 (.33)
a
Values have been reconverted to linear units; means based on log10 transformed values.
age experience (i.e., longer than 8 months) could be examined. However, some of the EA children were adopted at birth and thus we could not be sure that they would have been institutionalized. Taking these children out of the EA sample reduced that group to nine adopted from institutions but allowed us to be the most certain that they were drawn from a population similar in background characteristics to the RO children. Recomputing the DAC analyses with only these children in the EA group yielded identical results, F (2, 48) = 4.02, p < .05, with significant differences between the RO group and the EA group adopted from institutions (p < .05), and no difference between this subset of the EA children and the CB group. The individual DAC values have been graphed for all three groups in Figure 1. Note that only 4 (22%) of the RO children had DAC values that were below the median of the combined EA and RO groups. Furthermore, 31% of the combined EA and CB groups had DAC levels that were below the lowest value for the RO group. Finally, using the mean plus 2 SD of the combined EA and CB groups as a conservative estimate of elevated DAC (i.e., 1.24 in standard units), 4 (22%) of the RO group had DAC values above this cutoff. Thus, not only was a significant mean difference noted for the RO children, but also the magnitude of the effect appeared to be fairly large and the entire distribution for the RO children appeared to be shifted to higher values. Analyses of potential confounding factors To determine whether the age differences among the groups might be contributing to the group difference, the analysis of the DAC
measure was recomputed entering age at sampling as a covariate. The effect of the covariate was not significant, F (1, 56) = 0.00, ns. With the covariate in the model, the group difference continued to be significant, F (1, 56) = 3.2, p < .05. Similarly, because of the group differences in height percentiles, this variable was entered as a covariate. Its effect was not significant, regression F (1, 49) = 0.60, ns. Group continued to be significant after height was entered into the model, F (2, 49) = 3.69, p < .05. (Reduction in df was because not all children had height measures available.) Next we considered whether the markedly lower IQ in the RO group might account for the group differences in DAC. IQ was strongly related to RO status. When a binomial correlation was computed between a variable representing RO versus the other children and IQ, the resulting r was .67. This strong association created a significant problem of colinearity for any covariate analysis. Therefore, to address the question of whether IQ might be determining the cortisol results, we examined the correlation of cortisol levels and IQ within each of the groups. None of these correlations between IQ and DAC were significant (RO, r (15) = −.18, ns; EA, r (12) = −.47, ns; CB, r (19) = +.10, ns). We also examined the percentage of RO children with IQ measures below 85 who had DAC levels in the elevated range (i.e., less than mean plus 2 SD of combined EA and CB group). The Fisher Exact test was not significant (Fisher Exact = 0.29, ns). Thus, we could not conclude that low IQ accounted for the higher cortisol levels observed among the RO group. Months of institutionalization Next we turned to the question of whether the duration of institutional care for the RO chil-
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Figure 1. Daily average cortisol (mean of Z–log10 wakeup, Z–log10 noon, Z–log10 evening) averaged over the 3 days of assessment. Individual values are plotted for each child in the CB, EA, and RO groups. A line is drawn at the median of the combined EA and CB distribution.
dren was associated with their cortisol levels. First we examined whether children who had been in institutional care the longest had higher DAC levels. Longest was defined as being in the top third of the distribution for months of institutional care, which meant being institutionalized for 22 months or more. The DAC levels for children institutionalized for 22 months or more averaged 1.04 (in standard units), compared to 0.23 (in standard units) for those adopted after less than 22 months of institutional care, t (16) = −2.34, p < .056. The DAC measure weighted equally the wakeup, noon, and evening values, even though the wakeup and noon values were poor reflections of individual children’s cortisol levels. We therefore reexamined this
question using Pearson correlations between months of institutional rearing and the wakeup, noon, and evening cortisol measures separately. The correlations were not significant for the less reliable wakeup and noon values, r (16) = .009 and r (16) = −.06, respectively. The correlation with evening cortisol was highly significant, r (16) = .69, p < .001. To determine whether this was due to the association between IQ and duration of institutional stay, a partial correlation was computed controlling for IQ, partial r (14) = .66, p < .001. Thus, even controlling for IQ, for the RO children the longer they were in institutional care prior to adoption, the higher their evening cortisol levels. In Figure 2, this relationship has been graphed along with the evening cortisol
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Figure 2. A scatterplot of log10 evening cortisol against the months of institutional rearing. (CB children are plotted at 0 months of institutional care: (*) CB, (∆) EA, (䊐) RO.)
data for the EA and CB children (all CB graphed as 0 months of institutionalization). Discussion The results clearly showed that 6.5 years after adoption into families in Canada, children who lived for more than 8 months in orphanages in Romania (RO) exhibited the expected decrease in cortisol levels over the daytime hours, as did children adopted with less than 4 months of institutional care (EA) and children reared in their families of origin (CB). Thus there was no evidence of the lack of the normal decrease in cortisol levels over the day that was found for children living in Romanian institutions (Carlson et al., 1995; Carlson & Earls, 1997). Nonetheless, the RO group exhibited higher ambulatory cortisol levels. In addition, in the RO group, cortisol levels correlated with how long the children
had remained in institutions beyond 8 months. The question, however, is to what extent we can attribute these effects to the gross privation experienced by these children early in life. There are two obvious ways in which these differences might not directly reflect the effects of early experiences on the LHPA system. First, these cortisol effects might reflect indirect effects mediated by effects of institutionalization on the children’s behavior or on stressors in the family perhaps related to the children’s behavioral and emotional problems. Because we did not have concurrent behavioral measures on the children or their families, this alternative could not be ruled out. The second obvious alternative explanation is that prenatal conditions or genetic or family characteristics associated with orphanage placement produced the RO difference. Here the design implemented by the Simon
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Fraser Team helps to mitigate against this explanation. The children in the EA group were either already in institutions (9 of the 15) or were adopted from hospitals soon after birth prior to placement in an orphanage. Because the EA and CB children did not differ in their cortisol levels, it seems more likely that something associated with prolonged orphanage experience either affected the LHPA system or affected behavior, which in turn heightened stressors concurrent with the cortisol assessment. However, because we could not be certain that children adopted near birth actually would have been placed in institutions (i.e., the parents might have been wrong), we reanalyzed the cortisol data with only the EA children who had actually been in institutions at the time of adoption. The results remained the same. Thus, it seems unlikely that the RO cortisol difference reflected family or child characteristics that produced orphanage placement in the first place. The RO and EA children differed in several ways, however, that might confound interpretation of the results. The RO children were significantly older when the cortisol sampling was conducted: 8 months older than the CB children, on average, and 19 months older than the EA children. However, entering age as a covariate had no effect on the significance of the RO group difference. Furthermore, although the CB children were an average of over 13 months older than the EA children, no differences in cortisol were noted between these two groups. Thus, there is little reason to believe that age at sampling could account for the differences between the RO children and the other children. Similarly, more of the RO children were of short stature than were the EA and CB children (i.e., below the 20th percentile on height). However, controlling for height percentile had no effect on the group difference in cortisol levels. Finally, given that only a subsample of the original RO group participated in this cortisol study, it could be that parents of more disordered children chose to participate, while those whose children were doing well declined. While we cannot completely rule out this possibility because we lack concurrent behavior or family functioning measures, the comparisons that
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were made between this subsample and the total sample suggest that the subsample was representative. Thus, the families who participated in the RO group were ones with comparable maternal education and comparable child IQ at last assessment. Importantly, at the last assessment the Simon Fraser Team used their data to group the children into those with multiple, serious problems. About 30% of the total RO group fell into this category. In this study, 38% of our RO sample (or one child more than would have yielded 30%) was drawn from this multiple problem group. Thus, it seems unlikely that the cortisol difference for the RO group was due to which RO families chose to participate. Finally, as noted by the Simon Fraser research team (e.g., Ames, 1997; Morison & Ellwood, 2000), the longer the children lived in institutions, the more likely they were to exhibit below-normal IQs. Rutter and his colleagues reached a similar conclusion using their larger sample of Romanian adoptees in the United Kingdom (Castle et al., 1999). We were thus concerned that the presence of a large percentage of RO children with IQs of 85 or lower might explain the RO group difference. However, IQ was not significantly correlated with cortisol levels in the RO group. Thus, while there might be a relationship between low IQ and higher cortisol production were a larger sample to be examined, it did not seem in the present study that low IQ could account for the RO cortisol difference. The conclusion that the RO group difference was a function of gross privation was enhanced by evidence that within the RO group longer duration of institutional care correlated with higher cortisol levels. This effect was significant when the DAC measure was used and when only the evening cortisol measure was used. Cortisol levels should be close to zero in the evening near the lowest point of the daily cycle. Failure to bring cortisol concentrations to low levels at this time of day is believed to reflect a fundamental dysregulation of this neuroendocrine system (Young, Haskett, Grunhaus, Pande, Weinberg, Watson, & Akil, 1994). Elevations in evening levels have been found for some chil-
Ambulatory cortisol levels
dren with major depressive disorder (Brent, Ryan, Dahl, & Boris, 1995; Dahl, Ryan, Puig–Antich, Nguyen, Al-Shabbout, Meyer, & Perel, 1991). Indeed, it has been argued that the time near the nadir or lowest point of the daily cortisol rhythm should be a sensitive time to detect basal alterations in the axis. Thus, the fact that cortisol levels were elevated in the evening in association to how long the child had lived in an institution may be particularly meaningful. Nevertheless, it should be noted that cortisol levels were elevated at all time points and not just in the evening hours. The significant correlation between evening cortisol and duration of institutionalization and the lack of this significant association for wakeup or noon values may merely reflect the relative day-to-day instability of these latter measures. Another point to consider is the strength of the RO effect. Certainly, despite an average group difference, there was considerable overlap in the distributions. However, when we calculated the mean plus 2 SD of DAC for the combined EA and CB groups and used this as a conservative estimate of elevated cortisol levels, 4 of the 18 RO children (22%) had values that were above this cutoff. In contrast, only 4 (22%) of the RO children had daily averaged values below the median of the combined CB and EA distribution and none had levels in the bottom third of levels exhibited by CB and EA children. Thus nearly a quarter of the RO children appeared to have elevated levels of cortisol as they went about their everyday lives. In addition, the entire distribution of values for the RO children appeared to be shifted higher. In short, despite the overlap in values, the effect appeared to be consistent and substantial. While the results argue for an impact of factors associated with early orphanage care on the activity of this stress sensitive neuroendocrine system, they also raise several questions. One question is whether the results of the present study argue for a sensitive period in the organization of the LHPA system in humans. The results are certainly consistent with the rodent research where a sensitive period does appear to exist. However, for several reasons—not the least of which are the small
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sample size, the need for replication, and the possibility that concurrent stress related to the children’s behavior might be producing the elevations—caution is warranted in applying a sensitive period interpretation to these findings. It is also not clear what these elevations in cortisol might portend for these children’s futures. One prediction from the animal and adult research is that chronic elevations in cortisol should be associated with increased fearfulness, anxiety, and risk of depressive disorders (Heim et al.,1997; Rosen & Schulkin, 1998; Schulkin, 1994). In this context, it is noteworthy that none of the studies of Romanian-adopted children have reported increases in fear, anxiety, or depression. Indeed, for the full sample of RO children tested by the Simon Fraser team several years earlier, the predominant problems were ones in the externalizing spectrum (Ames, 1997). Anxiety and depression, however, are difficult to assess using measures like the Child Behavior Checklist, the measure used in previous studies of postinstitutionalized children (e.g., Ames, 1997; Verhulst et al., 1992). Thus, in future studies it will be important to examine LHPA activity in relation to assessments sensitive to problems of anxiety, fearfulness, and depression. Another prediction drawn from arguments posed by De Bellis and colleagues (1999) is that elevated cortisol could impair brain development leading to cognitive impairment. Although variations in cortisol within the RO group were not clearly associated with low IQ, certainly as a group the RO children evinced lower IQs at their last assessment. Alterations in LHPA function might have contributed. In conclusion, the results of this study raise many questions. Not only do they raise the need to replicate the findings, as the sample was small, but they also raise questions about whether the results generalize beyond the group of children adopted from Romanian orphanages of the Ceaus¸escu era. In the future, studies examining concurrent behavior and family stress will be needed to determine whether altered cortisol activity reflects early experiences or concurrent cortisol–experience associations. This study examined ambulatory cortisol levels. We do not know whether chil-
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dren with prolonged orphanage experience would show increased cortisol responses to stressors, and this needs to be examined. Finally, in order to more conclusively determine whether orphanage experiences alter activity of the LHPA system it will be necessary to assess children as they transition from institutional to family settings. Unfortunately, developmental studies of orphanage-reared children are quite feasible. The orphanages of Ceaus¸escu’s regime were not anomalies. Since 1990, nearly 73,000 children have been adopted internationally by families in the United States alone. Although Romania now accounts for
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few of these children, it is estimated that nearly 65% of internationally adopted children currently come from orphanages (Johnson, 2000). Like the postinstitutionalized children of the Ceaus¸escu era, they show growth declines characteristic of psychosocial dwarfism and delays in cognitive and social development. Economic and political conditions in their countries of origin result in orphanage conditions that in too many instances rival those experienced by the children in this study. Thus, there are likely to be many opportunities to replicate and extend this line of research.
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