Salivary Testosterone and Cortisol in Disruptive Children: Relationship to Aggressive, Hyperactive, and Internalizing Behaviors

Salivary Testosterone and Cortisol in Disruptive Children: Relationship to Aggressive, Hyperactive, and Internalizing Behaviors I

ANGELA SCARPA SCERBO, PH.D.,

AND

DAVID

J.

KOLKO, PH.D.

ABSTRACT Objective: To test predictions that basal salivary testosterone and cortisol are related to antisocial and internalizing

behaviors, respectively, and that cortisol moderates the testosterone-aggression relationship. Method: Saliva samples were assayed to determine testosterone and cortisol levels in 40 clinic-referred disruptive children (aged 7 through 14 years) who were rated on aggression, inattention/overactivity, and internalizing behavior by parents, teachers, and clinic staff members. Results: Results indicated significant positive relationships between testosterone and staff-rated aggression and between cortisol and parent-rated internalizing behavior. A significant negative relationship was found between cortisol and staff-rated inattention/overactivity. No interactions between testosterone and cortisol were found. These results were maintained regardless of age, racial background, height, weight, diagnosis, or medication status. Conclusions: Results suggest moderate relationships between testosterone and observed aggression, and between

cortisol and emotional behaviors, in a group of disruptive children. Cortisol did not moderate the testosterone-aggression relationship in this population. J. Am. Acad. ChildAdo/esc.Psychiatry, 1994, 33, 8:1174-1184. Key Words: testosterone, cortisol, aggression, disruptive behavior.

There is increasing recognition that biological factors play some role in the expression of antisocial behavior (Eysenck and Gudjonsson, 1989; Moffitt and Mednick, 1988; Raine and Scerbo, 1991), with recent research examining the functions of hormones on behavior (Rubin, 1987). Among animals, testosterone has been shown to facilitate aggression in various vertebrates (Archer, 1988; Brain, 1977; Harding, 1983), but primate studies have been less conclusive (Bernstein et al., 1983; Dixson, 1980; Eberhart et al., 1980). While testosterone tends to decrease with nondominance and reduced aggressivity in animals, however, cortisol has

Accepted April 2, 1994. From the Division of Child and Adolescent Psychiatry, Western Psychiatric Institute and Clinic, University ofPittsburgh School ofMedicine, Pittsburgh, PA. The authors thank Oscar Bukstein, MD., Boris Birmaher, M.D., and James W Dabbs, Ph.D., fOr their helpftl comments on drafts of this article; Jerome Barron and Kim Hinkle, R.N, fOr their help in data collection; and Dr. James Perel and Stacy StullfOr conducting the hormone assays. This work was conducted and the article written while Dr. Scerbo was a fellow at the Western Psychiatric Institute and Clinic, undertraininggrant T32 MH18269. Correspondence to Dr. Scerbo, Department ofPsychology, MS-94, Eastern Washington University, 5265th Street, Cheney, WA 99004-2431. 0890-8567/94/3308-1174$03.0010©1994 by the American Academy of Child and Adolescent Psychiatry.

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been shown to rise dramatically (MacLean, 1990). Furthermore, there seems to be a connection between these hormones in response to stress, namely an increase in cortisol with an accompanying decrease in testosterone (Henry, 1992). Such animal research raises the question of the existence of similar hormonal relationships to aggression in humans. Previous studies have shown high salivary, serum, and CSF testosterone levels in human adult males to be related to chronic aggressive behavior (Ehrenkranz et al., 1974), violent crime (Dabbs et al., 1987; Kreuz and Rose, 1972; Virkkunen et al., 1994), antisocial personality disorder (Dabbs et al., 1990; Dabbs and Morris, 1990), and peer ratings of "toughness" (Dabbs et al., 1987), although not all have found such relationships (Bain et al., 1987, 1988). Similarly, testosterone levels in adolescents have been related to "problem behaviors" such as smoking, drinking, or sex (Udry, 1989); verbal aggression (Olweus, 1987; Schalling, 1987); physical and provoked aggression (Olweus, 1987); and violent crime (Dabbs et al., 1991). Interestingly, Dabbs et al. (1991) found a significant interaction between testosterone and cortisol whereby a stronger

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testosterone-violence relationship was found for subjects with low cortisol levels. Others have found no evidence oftestosterone-aggression relationships in adolescents (Susman et al., 1987) or children (aged 4 to 10 years) (Constantino et al., 1993). More detailed reviews regarding the influence of testosterone on aggression may be found in Archer (1991) and Rubin (1987). Studies exploring the role of salivary, urinary, or serum cortisol in aggressive behavior have produced inconsistent findings. Virkkunen (1985) found low cortisol levels in adult males with antisocial personality disorder, habitual violence, and truancy and undersocialized conduct disorder in adolescence. Others have found no relationship between cortisol and antisocial personality disorder (Moss et al., 1990) or increased cortisol in aggressive subjects (Buydens-Branchey and Branchey, 1992). Likewise, relationships between low cortisol levels and disruptive behaviors in children have been found in some studies (Tennes and Kreye, 1985; Tennes et al., 1986; Vanyukov et al., 1993), but not others (Dabbs et al., 1991; Kruesi et al., 1989). Still, others found cortisol to moderate the relationship between testosterone and violence (Dabbs et al., 1991) or between conduct and anxiety disorders, with higher cortisol levels in conduct-disordered children who have comorbid anxiety (McBurnett et al., 1991). The finding of heightened cortisol levels in children with comorbid anxiety is consistent with prior work showing increased levels of salivary cortisol in inhibited children (Kagan et al., 1988) and stressed animals (Henry, 1992). Cortisol has also been found to be related to anxiety, depression, introversion, and arousal (Dabbs and Hopper, 1990; Foreman and Goodyer, 1988), although others have found no differences in cortisol levels of depressed versus control children and adolescents (Birmaher et al., 1992; Kutcher et al., 1991; Puig-Antich et al., 1989). If a relationshipexists between cortisol and internalizing behaviors, this may moderate the relationship between cortisol and disruptive/aggressive behaviors (McBurnett et al., 1991). In summary, the literature suggests that testosterone and cortisol may be related to disruptive/aggressive behavior, and cortisol may be more strongly related to internalizing behaviors. However, diversity in methodology makes it difficult to derive clear conclusions from these findings. One difference across studies involves the hormone collection procedures used, such

}. AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 33:8, OCTOBER 1994

as sampling from serum, urine, or saliva, or taking single versus multiple measurements. Validity data measures in this area have been equally diverse as represented by observations, ratings by professionals or parents, and archival records that evaluate variables ranging from violent behavior to simple oppositionalism. Finally, study samples have included schoolchildren, diagnosed inpatients, and incarcerated offenders. Given such heterogeneity, it· is encouraging that some consistent patterns have emerged, but further study is necessary to clarify the link between hormones and behavior, especially in young children. Few studies have studied hormone-aggression relationships using measures across sources or settings and in children clinically referred for disruptive behavior disorders. Such a study would contribute to our understanding of the manifestation and underlying mechanisms of clinically significant behavioral dysfunction in children. It has been suggested, for example, that antisocial individuals may be hyperresponsive to reward (Quay, 1988; Scerbo et al., 1990) or unable to learn from punishment (Fowles, 1980; Newman, 1987), based on an imbalance of two biologically based motivational systems, namely the Behavioral Activation System (BAS) and the Behavioral Inhibition System (BIS) (Gray, 1975). The BIS inhibits behavior in response to punishment, while the BAS activates behavior in response to reward. The relationship of testosterone and cortisol to these systems may be clarified by hormonebehavior research in antisocial children. This study measures salivary testosterone and cortisol in disruptive children referred for clinical services. Hormones are measured using saliva because it offers several advantages over serum measurement. Serum measurement, although standard and reliable, necessitates the use of venipuncture, which may be distressing and uncomfortable for subjects. Salivary measurement is relatively convenient to obtain and less distressing, minimizing reluctance for subjects to participate. Salivary samples provide measures of the biologically active or free portions of each hormone (Riad-Fahmy et al., 1982) and thus tend to show very high correlations with serum concentrations (Bober et al., 1988; Butler et al., 1989; Vittek et al., 1985; Woolston et al., 1983). Furthermore, salivary cortisol and testosterone have similar patterns of diurnal variation, showing increased morning levels and decreased evening levels (Butler et al., 1989; Foreman and Goodyer, 1988). Therefore,

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although it is desirable to measure hormones at several points throughout the day or on more than one day, obtaining a saliva sample in the morning provides a sufficient level of the hormone to be reliably detected, and research on salivary testosterone indicates correlations between days of approximately r = .64 (Dabbs, 1990), similar to the reliability of serum measurements (Gutai et al., unpublished) . Based on the aforementioned studies, four predictions are tested: (1) salivary testosterone levels will be positively related to aggressive behavior, (2) salivary cortisol levels will be negatively related to aggressive behavior, (3) salivary cortisol levels will be positively related to internalizing behavior, and (4) the testosterone-aggression relationship will be strongest for children with low cortisol levels. A limitation of previous research is addressed by collecting multiple measures of aggression, hyperactivity, and internalizing behavior from different informants in different settings (i.e., parents, teachers, and clinic staff). Hyperactivity and aggression are both examined because they are highly correlated behaviors (johnston et al., 1985; Stewart et al., 1981), thus making it important to assess whether hormone-aggression relationships are specific to aggressive behaviors. Such clarification seems necessary to elucidate variables related to their separate etiology, maintenance, and treatment. Finally, this study uses a clinic sample of children referred for disruptive behavior disorders. Based on the literature reviewed above, it seemed that hormones might be more specifically related to particular symptoms rather than diagnostic syndromes. Given the substantial degree of comorbidity in clinical populations, clarifying the relationship of hormonal markers to specific symptoms can provide useful information regarding the manifestation of particular behaviors in patients.

METHOD SUbjects Data were collected on 37 boys and three girls in an initial evaluation for the 1992 Summer Treatment and Enrichment Program, a 7-week treatment program for children with disruptive disorders. The children were 7 through 14 years old (mean = 11.18 years); 30 were Mrican-American and 10 were Caucasian. Hollingshead family class (two-factor) ranged from 1 to 4 (mean = 2.08).

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Each child received a comprehensive assessment by a child psychiatrist using a standardized clinical interview based on the Schedule for Affective Disorders and Schizophrenia for SchoolAge Children (Chambers er al., 1985), which used DSM-III-R diagnostic criteria. Nineteen had a diagnosis of conduct disorder (CD), 23 attention-deficit hyperactivity disorder (ADHD), and 17 oppositional defiant disorder (ODD). Of the 23 children with ADHD, 11 had comorbid CD , and 8 had comorbid ODD. Three children had a comorbid mood disorder (two dysthymia, one bipolar disorder). Seven children were taking medication at the time of hormone measurement (e.g., methylphenidate, clonidine, haloperidol, lithium).

Design and Measures Hormone collection occurred during the first eight program days. Behavioral and emotional symptom ratings were obtained from teachers, parents, and clinic staff after the child's intake interview. Staff ratings were completed daily and averaged across the seven program weeks. The psychiatrist and all raters were blind to results of the hormone assays. The experimenter obtaining saliva samples was blind to behavioral ratings. HormoneMeasurement. A salivarysample for hormone determination was collected ar a consistent time (between 9 and 10 A.M.) for each child, while seated in a separate office, after a 30-minute quiet period in a nonstressful situation. Saliva was collected using a commerciallaboratoty Salivette kit from Sarsredr, Inc. (Arlington Heights, IL) by having the child soak gauze in his or her mouth for 45 to 60 seconds, which was then put in a test tube, immediately placed into a freezer, and stored at -80°C until assayed. Salivary testosterone (nanograms/milliliter) and cortisol (micrograms/deciliter) concentrations were determined by the Clinical Pharmacology Laboratory of Western Psychiatric Institute and Clinic (Pittsburgh , PAl using a solid-phase radioimmunoassay procedure outlined by Diagnostic Products Corporation (Los Angeles, CA), modified for use with salivary samples. Each sample was processed in dupl icate. The intraassay coefficient of variations (CV) ranged from 0.04% to 2.85% (mean = 0.87%) for cortisol and from 0.02% to 4.20% (mean = 1.03%) for testosterone. Samples with an intraassay CV greater than 5% were retested. Too few assays were run to determine interassay CV for either testosterone or cortisol. Vital Signs. A single measurement of pulse rate and blood pressure was obtained at this time as a potential indicator of apprehension experienced at the time of saliva collection. High levels of stress might be expected to produce high levels of pulse rate and blood pressure. An oscillometric digital blood pressure meter (A & D Engineering, Inc, Milpitas, CA; model UA-751) was used, consisting of a pediatric cuff with a pressure valve placed around the upper left arm and attached to a digital reader that displayed systolic and diastolic blood pressure and pulse rate. Rating Scales. Several scales were used to assess behavioral and emotional problems. Aggressionwas measured using the Aggression subscale factor scores from the Child Behavior Checklist, parent (CBCL) and teacher (Teacher Report Form; TRF) versions (Achenbach and Edelbrock, 1983; Edelbrock and Achenbach, 1984), and from two items reflecting verbal and physical aggression toward others on the Overt AggressionScale (OAS) rated by staff (Yudofsky et aI., 1986). Inartention/overactivity was measured using the factor score from the Iowa-Conners (I/O-C) questionnaire rated by teachers and staff (Loney and Milich, 1982; Pelham er al., 1989) and from the first four items of the Conners Parent Questionnaire (Goyette et al., 1978), which correspond to four of the five I/O-C inatrention/overactivity items. Internalizing behavior was measured

]. AM. ACAD . CHILD ADOLESC . PSYCHIATRY, 33:8, OCTOBER 1994

HORMONES AND DISRUPTIVE BEHAVIOR using the Internalizing factor score from the CBCL and TRF, and from a clinic staff measure designed as a brief monitor of depressed mood, which consists of three items reflecting unhappiness, sad affect, and irritability.

verbal and physical aggression throughout the program ranged from 0 to 2.31 (on a scale of 0 to 4), suggesting somewhat milder forms of aggression displayed inprogram than at home or school. Staff OAS ratings, however, correlated positively but nonsignificandy with both parent (r = .21, not significant [NS]) and teacher (r = .38, NS) ratings. Mean inattention/overactivity scores for this sample were low to moderate, extending the full range of 0 through 12 for parents and 0 through 15 for teachers, but averaging 0.25 to 8.79 (on a scale of 0 through 15) for staff ratings throughout the program. Again, staff ratings of behavior in-program seem lower than

RESULTS Descriptive Information

Table 1 provides descriptive information regarding physical characteristics, hormonal concentrations, and behavioral measures. Children in this sample obtained average CBCL (range = 55 to 93) and TRF (range = 55 to 91) aggression scores falling within the clinical range (i.e., tscore of70 or greater). StaffOAS ratings of

TABLE 1 Means (Standard Deviations in Parentheses) for Physical, Hormonal, and Behavioral Characteristics by Gender and Race

Physical characteristics Age (yr) Height (inches) Weight (lbs) Hormones Testosterone (ng/mL) Cortisol (~g/dL) Behavioral measures Aggression Parent (CBCL) Teacher (TRF) Staff (OAS) Inattention/overactivity Parent (CPO) Teacher (I10-C) Staff (I10-C) Internalizing behavior Parent (CBCL) Teacher (TRF) Staff (DEP)

Boys

Girls

AfricanAmerican

Caucasian

Total

11.16 (1.90) 58.50 (5.14) 93.94 (29.07)

11.36 (2.59) 60.00 (1.41) 89.25 (3.89)

11.25 (2.03) 58.49 (5.06) 91.43 (27.42)

10.95 (1.62) 59.02 (5.09) 103.67 (32.02)

11.18 (1.92) 58.59 (4.99) 93.65 (28.18)

0.054 (0.026) 0.148 (0.081)

0.050 (0.000) 0.100 (0.046)

0.054 (0.027) 0.159 (0.083)

0.054 (0.022) 0.098 (0.044)

0.054 (0.025) 0.144 (0.079)

71.62 (12.48) 71.00 (11.55) 0.855 (0.732)

66.33 (16.39) 71.00 (4.24) 0.412 (0.257)

69.96 (12.12) 71.67 (11.48) 0.778 (0.681)

74.11 (14.24) 69.00 (10.45) 1.040 (0.898)

71.13 (12.66) 71.00 (11.07) 0.827 (0.718)

7.13 (3.64) 8.83 (4.00) 3.92 (2.50)

4.00 (2.83) 6.00 (2.83) 4.55 (2.84)

7.43 (3.82) 9.10 (4.28) 3.85 (2.49)

5.67 (2.92) 7.56 (2.92) 4.43 (2.59)

6.94 (3.64) 8.66 (3.96) 3.96 (2.48)

63.10 (10.08) 64.59 (10.44) 2.87 (1.02)

63.33 (14.57) 56.00 (0.00) 4.55 (1.16)

63.48 (9.54) 62.50 (10.03) 2.90 (1.16)

62.22 (12.54) 68.00 (10.73) 3.30 (0.73)

63.12 (10.27) 63.87 (10.26) 2.97 (1.09)

Note: Behavior rating scale is in parentheses: CBCL = Child Behavior Checklist; TRF = Teacher Report Form; OAS = Overt Aggression Scale; CPQ = Conners Parent Questionnaire; I10-C = Conners Inattention/Overactivity items; DEP = clinic staff measure of depressed mood. See text for explanation of each scale.

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at home or school, but correlate positively with parent (r= .39, p < .055) and teacher ratings (r= .41, p < .05). Because hyperactivity and aggression are often correlated (johnston et al., 1985; Stewart et al., 1981), measures of both were included to assess their relative relationships to testosterone and cortisol. Correlations were computed to examine the relationship of hyperactivity, as measured by the inattention/overactivity factor, and aggression in this sample. Results indicated significant correlations based on teacher (r = .70, P < .001) and staff (r = .37, P < .05), but not parent (r = .22, NS), ratings. Mean internalizing factor scores fell within normal limits, with CBCL scores ranging from 46 to 82 and TRF scores from 42 to 89. Staff ratings of depressed mood observed throughout the program ranged from 0.69 to 5.38 (on a scale of 0 through 9) and did not correlate with either teacher (r = .08, NS)-or parent internalizing ratings (r = - .13, NS). Mean testosterone and cortisol levels for the entire group were 0.054 ng/mL (range = 0.01 to 0.13 ng/ mL) and 0.144 J-lg/dL (range = 0.04 to 0.37 ug/dl.), respectively. Boys (n = 37) and girls (n = 3) had similar levels of testosterone (mean = 0.054 versus 0.05 ng/ mL) and cortisol (mean = 0.148 versus 0.10 J-lg/dL), and so it was decided to include the few girls in all analyses where their data were available. No significant differences in racial background (Caucasian versus African-American) were found for salivary testosterone. Cortisol levels were significantly lower in Caucasian children (t[38] = 2.22 , P < .035). However, racial status did not differentiate any of the behavioral variables associated with cortisol, suggesting that the racial difference in cortisol concentrations did not influence the cortisol-behavior relationships (see below for results of hormone-behavior relationships). Relationship of Hormones to Behavior

Correlations. Pearson correlations were computed between salivary testosterone and cortisol concentrations and each scale reflecting aggression, inattention/ overactivity, or internalizing behavior. Table 2 presents these correlations. Basal salivary testosterone concentration was significantly positively correlated with aggression as rated by teachers and staff, and with inattention/overactivity as rated by parents and teachers. Cortisol concentration was significantly positively correlated with parent-rated 1178

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internalizing behavior and significantly negatively correlated with staff-rated inattention/overactivity. Multiple Regressions. Multiple regression analyses were conducted to examine the separate and interactive effects of testosterone and cortisol in predicting scores on each of the scalesmeasuring aggression, inattention/ overactivity, and internalizing behavior that were significantly correlated with one of the hormones. The right-hand side of Table 2 presents the standardized ~ weights, partial r values, and t scores of the main effects from these analyses. Results indicated that testosterone level was a significant predictor of aggression rated by teachers and staff and inattention/overactivity rated by parents and teachers, and cortisol level was a significant predictor of parent-rated internalizing behavior and staff-rated inattention/overactivity. An interaction between testosterone and cortisol was found for teacher-rated inattenrion/overactivity, where the testosterone-behavior relationship was stronger for those with high (r = .57, P < .05) versus low (r = .40, NS) levels of cortisol. . Relationship of Hormones to Combined Ratings from Informants

Since behavior ratings were made by parents, teachers, and staff, supplemental analyses were conducted to examine the relationship of testosterone and cortisol to combined scores across informants. As described above, ratings of aggression and inattention/overactivity tended to intercorrelate positively among parents, teachers, and staff, while ratings of internalizing behavior did not. Scores on each scale were standardized and summed across informants for each symptom construct, and the aggregated scores were correlated with each hormone. Results indicated trends of positive relationships between testosterone and aggregated aggression (r= .50, p < .052) and inattention/overactivity (r = .36, P < .076), and no significant relationships between cortisol and any aggregate. Relationship of Hormones to Other Behaviors Associated with Aggression or Internalizing Problems

Supplemental analyseswere conducted with available measures of delinquency (i.e., subscale of the CBCL), oppositional behavior (i.e., Aggression factor of the I/O-C rated by teachers and staff), depression (i.e., Depression subscale of the CBCL), and anxiety (i.e.,

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HORMONES AND DISRUPTIVE BEHAVIOR

TABLE 2 Correlations and Multiple Regressions Showing Testosterone and Cortisol Relationships with Aggression, Inattention/Overactivity, and Internalizing Subscales Rated by Parents, Teachers, and Staff Correlations Construct Aggression P (CBCL) T (TRF) S (OAS) Inattention/overactivi ty P (CPQ) T (II0-C) S (II0-C) Internalizing behavior P (CBCL) T (TRF) S (DEP)

Test r

Regressions Cort r

.14 .47* .45**

.29 -.02 -.14

.39* .43* .13

-.16 -.15 -.36*

-.09 .21 -.08

.54*** -.03 -.25

Standardized ~

Partial i-

t

.48* .44*

.23 .18

2.47 2.60

.38* .41* -.35*

.14 .17 .12

2.19 2.45 2.01

.29

3.45

.55***

Note: Test = testosterone; Cort = cortisol; P = parent-rated; T = teacher-rated; S = staff-rated. Rating scale is in parentheses: CBCL = Child Behavior Checklist; TRF = Teacher Report Form; pAS = Overt Aggression Scale; CPQ = Conners Parent Questionnaire; I10-C = Conners Inattention/Overactivity items; DEP = clinic staff measure of depressed mood. See text for explanation of each scale. Regressions show main effects of testosterone or cortisol in predicting behavior.

*p < .05; **p < .01; ***p < .005.

Schizoid-Anxious subscale of the CBCL, Anxious subscale of the TRF) since they are often associated with aggression or internalizing behavior. Parent-rated delinquency (r = .73, P < .001), and teacher (r = .70, P < .001) and staff (r= .64, p < .001) ratings ofoppositional behavior were correlated with ratings of aggression; parent ratings of depression (r = .93, P < .001) and anxiety (r = .76, P < .001) were correlated with internalizing behavior; and teacher ratings of anxiety (r = .78, P < .001), but not depression (r = .16, NS), were correlated with internalizing behavior. None of these were significantly correlated with testosterone. Cortisol was positively correlated with parent-rated depression (r = .58, P < .01) and negatively correlated with staffrated oppositional behavior (r = - 040, P < .05). Relationship of Hormones to Physical Characteristics, Vital Signs, Diagnosis, and Medication Status

Age (r = 042, P < .008), height (r = .56, P < .002), and weight (r = .36, P < .045) were significantly correlated with testosterone, but not cortisol. Body mass (weight/height) was not significantly correlated with either hormone. A plot of testosterone by age suggested that testosterone levels were greater in children aged 11 and older. Regression analyses were repeated by adding age, height, and weight as predictor variables for each analysis in which a significant effect

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for testosterone was found. The effect for testosterone remained significant only for staff-rated aggression. While age, height, and weight might be expected to covary with sexual maturation, they are limited stand-in measures for Tanner staging. Recognizing this limitation, the children were divided into those who were younger than 9 years old (n = 6) or 9 and older (n = 34) to assess possible differencesin the testosteronebehavior relationships between prepubertal and pubertal subjects. Age 9 was chosen as a cutoff point because normative data indicate that 97% of9-year-old children are prepubertal (i.e., Tanner stage I) (Tanner, 1962). The older group of children had a mean testosterone level that was 1.6 times greater than that of the younger group of children (0.037 versus 0.057 ng/mL). If pubertal status were influencing the results, correlations between testosterone and aggression or inattention/ overactivity should be larger in the older children and nonexistent in the younger children. Although nonsignificant due to the reduced n size, however, the younger group of children actually obtained correlations that were larger in magnitude (for teacher-rated aggression, r = .99; for staff-rated aggression, r = .75; for parent-rated inattention/overactivity, r = .83; and for teacher-rated inattention/overactivity, r = .77) than those of the older children (r = .35, NS; r = AI, P < .05; r = .32, NS; r = .36, NS, respectively).

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Testosterone and cortisol were not significantly correlated with pulse rate, systolic blood pressure, or diastolic blood pressure. Furthermore, t tests indicated no significant differences in pulse rate, systolic blood pressure, or diastolic blood pressure between groups with high versus low levels of either testosterone (mean = 87.41 versus 89.14 beats per minute, mean = 107.83 versus 110.71 mm Hg, mean = 73.42 versus 74.95 mm Hg, respectively) or cortisol (mean = 86.00 versus 90.88 beats per minute, mean = 113.12 versus 106.41 mm Hg, mean", 76.31 versus 72.59 mm Hg, respectively), suggesting that children with high versus low levels of either hormone had similar levels of blood pressure and pulse rate at the time of saliva collection. Because having a diagnosis of CD, ADHD, or ODD is often associated with aggression, t tests were conducted to examine differences in hormonal levels of children with and without these diagnoses. No significant differences were found in mean levels for children with or without CD (mean = 0.057 versus 0.052 ng/mL for testosterone; mean = 0.151 versus 0.138 ug/dl, for cortisol), ADHD (mean = 0.057 versus 0.050 ng/mL for testosterone ; mean = 0.150 versus 0.134 ug/dl, for cortisol), or ODD (mean = 0.052 versus 0.056 ng/mL for testosterone; mean = 0.146 versus 0.143 ug/dl, for cortisol), suggesting that diagnostic categories alone did not differentiate hormonal levels. To assess the effects of medication status, t tests were conducted to compare hormonal levelsin children who were (n = 7) and were not (n = 33) taking medication. Since only seven subjects were taking medication and since, among them , four different drugs were used, it was not possible to assess the separate effects of.any one medication. However, no significant differences in testosterone or cortisol levels were found . among the seven children taking any medication and those taking no medication (mean = 0.063 versus 0.052 ng/mL for testosterone; 0.134 versus 0.146 Ilg/dL for cortisol), .indicating that simply taking a medication did not significantly affect hormone levels.

DISCUSSION Hormones and Behavior

Testosterone. With some qualification, the main results are consistent with the hypothesis that higher

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concentrations of basal testosterone are related to aggressive behavior, but not with the hypothesis that cortisol moderates this relationship. Relationships to testosterone seemed specific to observed aggressive behavior. These results in child patients extend those of previous studies documenting positive relationships between testosterone and antisocial behaviors in adolescents (Dabbs et al., 1991; Olweus, 1987; Schalling, 1987; Udry, 1989) and adults (Dabbs et al., 1987, 1990; Dabbs and Morris , 1990; Ehrenkranz et al., 1974), but contrast with the negative results of Constantino et al. (1993) in severely aggressive prepubertal boys. The use of serum versus salivary measures and a comparison of categorical groups versus symptoms on a dimension of severity may account for the difference in findings. It is also possible that the relationship between testosterone and aggression does not become manifest until later in childhood, although when our sample was divided into younger versus older children, the results suggested that the relationship exists in younger children as well. Hyperactivity and aggression are highly correlated behaviors (johnston et al., 1985; Stewart et al., 1981) that represent semi-independent dimensions (Atkins et al., 1989; Hinshaw, 1987; Routh, 1983) . Although hyperactivity and aggression were correlated in our sample, testosterone was significantly related to staffrated aggression, but not hyperactivity, when age, height, and weight were controlled. Teacher and staff ratings of oppositional behavior and parent-rated delinquency were correlated with ratings of aggression, but not with testosterone level. These results suggest that testosterone may be a biological variable related to the expression of observed aggression, and this relationship is not simply accounted for by oppositionalism, hyperactivity, or delinquency. Cortisol Results were consistent with the hypothesis that higher concentrations of basal cortisol are related to internalizing behavior. However, contrary to hypotheses, cortisol did not significantly relate to aggression and no interactions with testosterone were found. Relationships to cortisol seemed less specific, as cortisol was related positively with internalizing behavior and negatively with inattention/overactivity. These results are not consistent with studies showing a negative relationship with aggressive or antisocial behaviors in children (Tennes and Kreye, 1985; Tennes et al., 1986; Vanyukov et al., 1993) or those studies implicating cortisol as a moderating variable (Dabbs

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et al., 1991; McBurnett et al., 1991). On the other hand, cortisol was negatively related with inattention/ overactivity and oppositional behavior, and thus shows a relationship with some disruptive behaviors. The finding that cortisol is related to heightened internalizing behavior is consistent with studies finding increased levels of cortisol in inhibited children (Kagan er al., 1988) and depressed adolescents (Foreman and Goodyer, 1988), and showing a positive relationship with anxiety, depression , introversion, and arousal (Dabbs and Hopper, 1990). In our sample, depressed mood seemed related to increased cortisol more so than anxiety which, supplemenrally, was not significantly correlated with cortisol. Theoretical Significance

These results may provide additional insight into a theoretical perspective on the development of antisocial behavior based on the notion that an imbalance of two biologically based motivational systems (i.e., the BIS and BAS) underlies antisocial behavior (Gray, 1975). The BIS serves to inhibit behavior in response to punishment, while the BAS serves to activate behavior in response to reward. It has been suggested that a hyperresponsivity to reward, and thus an overactive BAS relative to BIS, is one underlying factor of antisocial personality (Quay, 1988). In this study, testosterone, but not cortisol, was related to aggression, suggesting that testosterone may be a biological variable related to antisocial and reward-seeking behavior as a coping mechanism mediated through the BAS. An underactive BIS relative to the BAS, leading to an inability to learn from cues of punishment, has also been implicated in antisocial behavior (Fowles, 1980; Newman, 1987). Given the current results showing a relationship between cortisol 'and internalizing behaviors, the question of whether cortisol is a biological variable related to withdrawal/avoidance as a coping mechanism mediated through the BIS merits inquiry. In sum, the results showing a relationship between aggression and testosterone, but not cortisol, are in accord with the position that an overactive BASrelative to BIS is associated with antisocial behavior (Quay, 1988) and that the two systems may have different biological underpinnings (Gray, 1975). Clinical Significance

The documentation of behavioral relationships with testosterone and cortisol extends prior studies by show-

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ing relationships to specific behavioral constructs in disruptive children. It is interesting to note that while aggressive, hyperactive, and oppositional behaviors were related to testosterone or cortisol, the hormones did not differ between groups with and without a diagnosis of CD , ODD, or ADHD. This suggests that, when looking at individual differences due to hormonal variability, a syndrome may not be as important an indicator as the symptoms themselves along a dimension of severity (Kruesi et al., 1989; Vanyukov et al., 1993). The suggestion that symptom variability may be a more sensitive measure than diagnosis per se is further substantiated by our finding that cortisol was significantly related to internalizing behavior even though all subjects had a diagnosis of a disruptive behavior disorder. Given that many clinic patients have cornorbid diagnoses, therefore, it may be useful to assess hormone function in terms ofspecificsymptomatology. Methodological Considerations

Informant Sophistication. The current hormone-behavior relationships differed substantially depending on the source of information used. For example, after we controlled for age and size, testosterone correlated significantly with aggression when rated by staff, but not parents or teachers. Cortisol correlated significantly with hyperactivity and oppositionalism only when rated by staff, and with internalizing behavior only when rated by parents. One reason for this discrepancy may be that, relative to other adults, staff are more adept at noticing disruptive behaviors while parents are better at noticing mood or internalizing behaviors, which can go unnoticed in structured settings with groups of children. Timing in Measurement. An alternative explanation might be differences due to the method of measurement. The staff ratings reflect daily measurements of observed behavior, while the teacher and parent ratings reflect perceptions of the child over a longer period of time. The staff ratings, therefore, might be seen as more reliable or accurate measures of current behavior. Furthermore, relationships of disruptive behaviors to testosterone and cortisol might be stronger for currently observed behavior, while relationships of internalizing behavior to cortisol might represent a more longstanding trait. Multiple Forms ofAggression. It is also possible that discrepancy in ratings across multiple informants and 1181

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settings reflects a diversity in forms of aggression. Different typologies of aggression have been suggested both among animals (Blanchard, 1980; Moyer, 1976) and humans (Campbell et al., 1985; Dodge, 1991). Indeed, in this sample, staff aggression ratings were not significantly related to parents' or teachers' ratings, and a combined measure based on all informant ratings reduced the magnitude of the relationship with testos,terone. Perhaps these results indicate that different forms of aggression were being tapped. In any case, an important implication of informant variance is that findings of hormone-behavior relationships may differ by the sources and measures used (e.g., Constantino et al. 1993; Dabbs et al., 1991; Olweus, 1987; Schalling, 1987). Limitations

While our results represent expected hormone-behavior relationships, they need to be viewed within the context of severallimitations. The pattern of significant results was consistent with hypothesized formulations and previous literature, but the small sample size may have reduced power to detect other significant relationships. Another limitation is the reliability of hormone collection given that only one sample was taken and this was through the saliva rather than blood. Single measurements of salivary testosterone, however, show moderately high reliability (Dabbs, 1990), and the convenience afforded by a single salivary measurement provided the opportunity to study a biological variable in a sample of children attending a treatment program for a limited time and on a voluntary outpatient basis. Tanner stage was not obtained, but to evaluate the influence of sexual maturation on hormonal level, age, height, and weight, which are expected to covary with sexual maturation, were taken into account. These developmental measures were not related to cortisol and did not influence the results showing a main effect for testosterone on staff-rated aggression. Even the younger children in the sample, who are likely to be preadrenerchal, showed large testosterone-behavior correlations. This would be unexpected if sexual maturation alone was influencing the results. It should be cautioned, however, that age, height, and weight are clearly inferior stand-in measures for pubertal status and so, lacking Tanner staging, the current analyses cannot clearly establish that sexual maturation was not influencing at least some of the results.

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Testosterone and cortisol can also be influenced by state-dependent stress (Wilson and Foster, 1992). While a testing situation might be a mild stressor, neither pulse rate nor blood pressure in this sample was related to testosterone or cortisol. In addition, subjects with high versus low levels of testosterone or cortisol did not significantly differ in their heart rate or blood pressure, suggesting that any possible apprehension from the testing situation was not associated with hormone levels measured. Because all children in this study were clinic-referred for intensive treatment, these results may not generalize to the general population. Of course, children with problems severe enough to warrant clinical attention are an important subsample to study given the likelihood that they are biologically and environmentally vulnerable to heightened antisocial behavior. Some children were taking medication during the study, but their hormone levels did not significantly differ from the rest of the sample. Given the aforementioned limitations, it is important that future research be conducted to assess the replicability and generalizability of these findings. Summary

The current analyses suggest moderate relationships between testosterone and observed aggression and between cortisol and emotional (internalizing) behaviors in disruptive children. Testosterone and cortisol did not interact and, in fact, seemed to tap relatively independent sets of behaviors. The results are consistent with the position that testosterone is a biological factor related to antisocial behavior, perhaps reflecting an overactive BAS, and also highlight the importance of targeting patient symptomatology in addition to diagnostic syndromes. Future research needs to clarify the roles of cortisol and testosterone in the origins and maintenance of childhood behavioral and emotional problems. For example, testosterone-aggression relationships may differ by type of aggression (e.g., instrumental versus hostile, provoked versus unprovoked) or the degree to which certain psychological characteristics (e.g., guilt, hostility) are salient. Furthermore, the influence of hormone variation on the stability of behavior or the impact of treatment may be important factors to examine in future research.

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HORMONES AND DISRUPTIVE BEHAVIOR

REFERENCES Achenbach TM, Edelbrock C (1983), ManualfortheChildBehavior Checklist and Revised Child Behavior Profile. Vermont: Queen City Publishers Archer] (1988), TheBehavioural Biology ofAggression. Cambridge, England: Cambridge University Press Archer] (1991), The influence of testosterone on human aggression. Br

J PsychoI82:1-28 Atkins MS, Pelham WE, Licht MH (1989), The differential validity of teacher ratings of inattention/overactivity and aggression. J Abnorm

Child PsychoI17:423-435 Bain ], Langevin R, Dickey R, Ben-Aeon M (1987), Sex hormones in murderers and assaulrers, Behavioral Science and the Law 5:95-101 Bain], Langevin R, Dickey R, Hucker S, Wright P (1988), Hormones in sexually aggressive men. I. Baseline values for eight sex hormones. II. The ACTH rest. Annals of Sex Research 1:63-78 Bernstein I, Gordon TP, Rose RM (1983), The interaction of hormones, behavior and social context in nonhuman primates. In: Hormones and Aggressive Behavior, Svare BB, ed. New York: Plenum, pp 535-561 Birmaher B, Ryan ND, Dahl RE, Rabinovich H (1992), Dexamethasone suppression test in children with major depressive disorder. JAm Acad ChildAdolesc Psychiatry 31:291-297 Blanchard DC (1980), Applicability of animal models to human aggression. In: Biological Perspectives on Aggression, Flannelly K], Blanchard R], Blanchard DC, eds. New York: Alan R. Liss, pp 49-74 Bober ]F, Weller EB, Weller RA, Tait A (1988), Correlation of serum and salivary cortisol levels in prepubertal school-aged children. J Am

Acad ChildAdolesc Psychiatry 27:748-750 Brain PF (1977), Hormones and Aggression. Annual Research Reviews, Vol 1. Montreal: Eden Press Butler GE, Walker RF, Walker RV~ Teague P, Riad-Fahmy D, Ratcliffe SG (1989), Salivary testosterone levels and the progress of puberty in the normal boy.Clin Endocrinol (Oxj) 30:587-596 Buydens-Branchey L, Branchey MH (1992), Cortisol in alcoholics with a disordered aggression COntrol. Psychoneuroendocrinology 17:45-54 Campbell A, Muncer S, Bibel D (1985), Taxonomies of aggressive behavior: a preliminary report. Aggressive Behavior 11:217-222 Chambers W], Puig-Antich ], Hirsch M er al. (1985), The assessment of affective disorders in children and adolescents by semi-strucrured interview. Arch Gen Psychiatry 42:696-702 Constantino ]N, Grosz D, Saenger P, Chandler DW, Nandi R, Earls F] (1993), Testosterone and aggression in children. JAm Acad Child

Adolesc Psychiatry 32:1217-1222 Dabbs ]M (1990), Salivary testosterone measurements: reliability across hours, days, and weeks. Physiol Behav 48:83-86 Dabbs ]M, Frady RL, Carr TS, Besch NF (1987), Saliva testosterone and criminal violence in young adult prison inmates. Psychosom Med 49:174-182 Dabbs ]M, Hopper CH (1990), Cortisol, arousal, and personaliry in two groups ofnormal men. Personality andIndividualDifferences 11:931-935 Dabbs ]M, Hopper CH, ]urkovic G] (1990), Testosterone and personality among collegestudents and military veterans. Personality and Individual Differences 11:1263-1269 Dabbs ]M, ]urkovic G], Frady RL (1991), Salivarytestosterone and cortisol among late adolescent offenders. J Abnorm Child PsychoI19:469-478 Dabbs ]M, Morris R (1990), Testosterone, social class, and antisocial behavior in a sample of 4,462 men. Psychological Science 1:209-211 Dixson AF (1980), Androgens and aggressive behavior in primates: a review.

Aggressive Behavior 6:37-67 Dodge KA (1991), The structure and function of reactive and proactive aggression. In: The Development and Treatment of Aggression, Pepler D], Rubin KH, eds. Hillsdale, N]: Lawrence Erlbaum Associates Eberhart ]A, Keverne EB, Meller RE (1980), Social influences on plasma testosterone levelsin male Talapoin monkeys. HormBehav 14:247-266 Edelbrock C, Achenbach TM (1984), The teacher version of the Child Behavior Profile: I. Boys aged 6-11. J Consult Clin Psycho152:207-217 Ehrenkranz], Bliss E, Sheard MH (1974), Plasma testosterone: correlation with aggressive behavior and social dominance in man. Psychosom

Med 36:469-475

]. AM. ACAD. CHILD ADOLESC. PSYCHIATRY, 33:8, OCTOBER 1994

Eysenck H], Gudjonsson GH (1989), The Causes and Cures ofCriminality. New York: Plenum Press Foreman DM, Goodyer 1M (1988), Salivary cortisol hypersecretion in juvenile depression. J Child Psychol Psychiatry 29:311-320 Fowles DC (1980), The three arousal model: implications of Gray's two-factor learning theory for heart rate, electrodermal activity, and psychopathy. Psychophysiology 17:87-104 Goyette CH, Conners CK, Ulrich RF (1978), Normative data on revised Conners parent and teacher rating scales. J Abnorm PsychoI6:221-236 Gray]A (1975), Elements ofa Two-Process Theory ofLearning. New York: Academic Press Harding CF (1983), Hormonal influences on avian aggressive behavior. In: Hormones and Aggressive Behavior, Svare BB, ed. New York: Plenum, pp 435-467 Henry ]P (1992), Biological basis of the stress response. Integr Physiol

Behav Sci 27:66-83 Hinshaw SP (1987), On the distinction between attentional deficitsl hyperactivity and conduct problems/aggression in child psychopathology. Psychol Buill 01:443-463 Johnston C, Pelham WE, Murphy HA (1985), Peer relationships in ADDH and normal children: a developmental analysis of peer and teacher ratings. J Abnorm Child Psychol13:89-100 Kagan ], Reznick ]S, Snidman N (1988), Biological bases of childhood shyness. Science 240:167-171 Kreuz LE, Rose RM (1972), Assessment of aggressive behavior and plasma testosterone in a young criminal population. Psychosom Med34:321-332 Kruesi M]P, Schmidt ME, Donnelly M, Hibbs ED, Hamburger SD (1989), Urinary free cortisol output and disruptive behavior in children. JAm

Acad ChildAdolesc Psychiatry 28:441-443 Kutcher S, Malkin D, Silverberg], Marton P (1991), Nocturnal cortisol, thyroid stimulating hormone, and growth hormone secretory profiles in depressed adolescents. JAm AcadChildAdolesc Psychiatry 30:407-414 Loney], Milich R (1982), Hyperactivity, inattention, and aggression in clinical practice. In: Advances in Developmentaland Behavioral Pediatrics, Vol 3, Wolraich M, Routh DK, eds. Greenwich, CT: ]Ar Press, pp 113-147 MacLean PD (1990), The Triune Brain in Evolution: Role in Paleocerebral Functions. New York: Plenum McBurnett K, Lahey BB, Frick P] et al. (1991), Anxiety, inhibition, and conduct disorder in children: II. Relation to salivary cortisol. J Am

Acad ChildAdolesc Psychiatry 30:192-196 Moffitt TE, Mednick SA, eds. (1988), Biological Contributions to Crime Causation. Boston: Martinus Nijhoff Moss HB, Yao ]K, Panzuk GL (1990), Serotonergic responsivity and behavioral dimensions in antisocial personality disorder with substance abuse. Bioi Psychiatry 28:325-338 Moyer KE (1976), The Psychobiology of Aggression. New York: Harper and Row Newman]P (1987), Reaction to punishment in extraverts and psychopaths: implications for the impulsive behavior of disinhibited individuals. JournalofResearch in Personality 21:464-480 Olweus D (1987), Testosterone and adrenaline: aggressive antisocial behavior in normal adolescent males. In: The Causes ofCrime: New Biological Approaches, Mednick SA, Moffitt TE, Stack SA, eds. Cambridge, England: Cambridge University Press, PP 239-262 Pelham WE, Milich R, Murphy DA, Murphy HA (1989), Normative data on the IOWA Conners Teacher Rating Scale. Journal ofClinical Child

Psychology 18:259-262 Puig-Anrich ], Dahl RE, Ryan N, Novacenko H (1989), Cortisol secretion in prepubertal children with major depressive disorder: episode and recovery. Arch Gen Psychiatry 46:801-809 Quay HC (1988), The behavioral reward and inhibition system in childhood behavior disorders. In: AttentionDeficitDisorder, Vol 3, Bloomingdale LM, ed. Oxford, England: Pergamon, pp 176-186 Raine A, Scerbo A (1991), Biologicaltheories ofviolence. In: Neuropsychology ofAggression, Milner ]S, ed. Norwell, MA: Martinus Nijhoff, pp 1-25 Riad-Fahmy D, Read GF, Walker RF, Griffeths K (1982), Steroids in saliva for assessing endocrine function. Endocr Rev 3:367-395

1183

SC ERBO AND KOLKO

Routh DK (1983), Attention deficit disorder: its relationships with activity, aggression, and achievement. Advancesin Deuelopmental and Behavioral

Pediatrics4:125- 163 Rubin RT (1987), The neuroendocrinology and neurochem istry of antisocial behavior. In: The Causes of Crime: New BiofqgicalApproaches, Medn ick SA, Moffitt TE, Stack SA, eds. Cambridge, England : Cambridge University Press, pp 239-262 Scerbo A, Raine A, O'B rien M, Ch an C] , Rhee C, Smiley N (1990), Reward dom inance and passive avoidance learning in adolescent psychopaths. J

Abnorm Child PsycholI8 :451-463 Schalling D (1987), Personality correlates of plasma testosterone levels in young delinquents : an example of person-situation interaction? In: The . Causes of Crime: New Biological Approaches, Mednick SA, Moffitt TE, Stack SA, eds. Cambridge, England : Cambridge University Press, pp 283-291 Stewart MA, Cummings C, Singer S, DeBlois CS (1981), The overlap between hyperactive and unsocialized aggressive children. J ChildPsychol

Psychiatry 22:35-45 Susman EJ, Inoff-Germain G , N otrlernann ED, Loriaux DL, Cutler GB Jr, Chrousos GP (1987), Hormones, emotional dispositions, and aggressive attributes in young adolescents. Child Dev 58:1114-1134 Tanner JM (1962), Growth at Adolescence, 2nd ed. Oxford, England : Blackwell Scientific Publications T ennes K, Kreye M (I 985), Children's adrenocortical responses to classroom activities and tests in elementary school. Psychosom Med 47:451-4 60

1184

T ennes K, Kreye M, Avitable N , Wells R (1986), Behavioral correlates of excreted carecholamines and cortisol in second-grade children. J Am

Acad Child Psychiatry 25:764-770 'Udry JR (1989), Biosocial models of adolescent problem behaviors. Soc

Biol37:1-10 Vanyukov MM , Moss HM, Plail JA, Blackson T, Mezzich AC, T arter RE (1993), Antisocial symptom s in preadolescent boys and in their parents: associations with cortisol. Psychiatry Res 46:9- 17 Virkkunen M (1985), Urinary free cortisol secretion in habitually violent offenders. Acta PsychiatrScand 72:40-44 Virkkunen M, Rawlings R, Tokola R, RussellE (1994) , CSF biochemistries, glucose metabolism, and diurnal activity rhythm s in alcoholic, violent offenders, fire setters, and healthy volunteers. Arch Gen Psychiatry 51:20-27 Vittek J, L'Hommedieu DG , Gordon GG , Rappaport SC, Southren AL (1985), Direct radioimmunoassay (RIA) of salivary testosterone: correlation with free and total serum testosterone. Lift Sci 37:711-716 Wilson JD, Foster DW, eds (1992), Williams' Textbook ofEndocrinology, Sth ed. Philadelphia: WB Saunders Woolston JL, Gianfredi S, Gertner JM , Paugus JA, Mason JW (1983), . Salivary cortisol: a nontraurnatic sampling technique for assaying cortisol dynamics. JAm Acad Child Adolac Psychiatry 22:474-476 Yudofsky SC, Silver JM, Jackson W , End icott J, Williams D (1986), The O vert Aggression Scale for the objective rating of verbal and physical aggression. Am J Psychiatry 143:35-39

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