The revised version of the Screen for Child Anxiety Related Emotional Disorders (SCARED-R): Factor structure in normal children

PERGAMON Personality and Individual Differences 26 (1999) 99±112 The revised version of the Screen for Child Anxiety Related Emotional Disorders (SCARED-R): Factor structure in normal children Peter Muris a, *, Harald Merckelbach a, Henk Schmidt a, Birgit Mayer b a Department of Psychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands b Department of Experimental Abnormal Psychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands Received 18 December 1997 Abstract The revised version of the Screen for Child Anxiety Related Emotional Disorders (SCARED-R) is a self-report questionnaire that measures symptoms of DSM-IV linked anxiety disorders in children. The present study examined the factor structure of the SCARED-R in a sample of 674 normal Dutch school children aged 8 to 13 years. Exploratory factor analysis (principal components with oblimin rotation) clearly pointed in the direction of a 1-factor solution, suggesting that when applied to samples of normal children, the SCARED-R is a unidimensional measure. Additional exploratory and con rmatory factor analyses carried out on parts of the SCARED-R provided some support for the presence of the following factors: panic disorder, generalized anxiety disorder, separation anxiety disorder, school phobia, social phobia and three types of speci c phobias. Implications of these ndings for the use of the SCARED-R are brie y discussed. # 1998 Elsevier Science Ltd. All rights reserved. Keywords: Anxiety disorders; Screen for Child Anxiety Related Emotional Disorders; Self-report questionnaire; Normal children; Factor analysis 1. Introduction Anxiety disorders are one of the most common psychiatric problems in children. Estimates for the presence of any anxiety disorder range between 5.7 and 17.7%, with half of them exceeding the 10% rate (Costello and Angold, 1995). The latest edition of the Diagnostic and * Corresponding author. E-mail: p.muris@psychology.unimaas.nl S0191-8869/98/$19.00 # 1998 Elsevier Science Ltd. All rights reserved. PII: S0191-8869(98)00130-5

100 P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 Statistical Manual of Mental Disorders (DSM-IV; APA, 1994) which is the most current classi catory system in many countries (including The Netherlands), recognizes the following anxiety disorders in children: generalized anxiety disorder, separation anxiety disorder, panic disorder, speci c phobia, social phobia, obsessive±compulsive disorder and posttraumatic or acute stress disorder. Epidemiological studies have revealed that generalized anxiety disorder, separation anxiety disorder and speci c phobias are the most commonly diagnosed anxiety disorders, occurring in about 5% of the children. Social phobia and panic disorder are less frequent with prevalence rates generally below 2%, while obsessive±compulsive disorder and posttraumatic or acute stress disorders are even more rare. There is evidence to suggest that subclinical manifestations of anxiety disorders are also relatively prevalent among children. For example, Bell-Dolan et al. (1990) found that symptoms of generalized anxiety disorder, separation anxiety disorder, and speci c phobias were present in 20±30% of a sample of neverpsychiatrically ill children. Structured and semistructured interviews can be used to reliably assess anxiety disorders symptomatology in children. However, these interviews are time-consuming and often require trained interviewers. Alternatively, self-report questionnaires can be employed to measure anxiety symptoms in children. Currently, the three most widely used scales for this purpose are the Revised Children's Manifest Anxiety Scale (RCMAS; Reynolds and Richmond, 1978), the State-Trait Anxiety Inventory for Children (STAIC; Spielberger, 1973) and the Fear Survey Schedule for Children, Revised (FSSC-R; Ollendick, 1983). It should be noted that these scales are global and unidimensional and not keyed to the separate anxiety disorders as listed in the DSM. Recently, several attempts have been made to develop multidimensional questionnaires for assessing childhood anxiety symptoms. A rst example is the Multidimensional Anxiety Scale for Children (MASC; March et al., 1997), a self-report measure comprising four empiricallyderived domains of childhood anxiety: physical anxiety, harm avoidance, social anxiety and separation anxiety. Another example is the Children's Anxiety Scale (CAS; Spence, 1997) that taps symptoms of a number of DSM-de ned anxiety disorders, namely panic disorder, separation anxiety disorder, social phobia, obsessive±compulsive disorder and generalized anxiety disorder. In addition, the CAS contains a physical fears scale which represents the DSM-category of speci c phobias. Interestingly, Spence (1997) showed in a factor-analytic study that anxiety symptoms as listed in the CAS cluster into subtypes of anxiety problems that are largely consistent with the classi cation of anxiety disorders as proposed in the DSM. The Screen for Child Anxiety Related Emotional Disorders (SCARED; Birmaher et al., 1997) is also a multidimensional questionnaire that purports to measure DSM-de ned anxiety symptoms. Factor analysis performed on the SCARED scores of clinically referred children revealed that the 38 items of the SCARED can be allocated to ve separate anxiety subscales. Four of these subscales represent anxiety disorders that correspond with DSM categories, namely panic disorder, generalized anxiety disorder, social phobia, and separation anxiety disorder. The fth subscale is school phobia which, according to Birmaher et al. (1997, p. 551) can best be considered as ``a common clinical entity that is seen both comorbidly and independently from other anxiety disorders''. Muris (1997) revised the SCARED in three ways. To begin with, school phobia items were joined to the separation anxiety disorder subscale. This was done because the DSM (see especially the DSM-III-R; APA, 1987) views school

P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 101 phobia as a symptom of separation anxiety disorder. Secondly, 15 new items were added in an attempt to index symptoms of speci c phobia. The DSM-IV distinguishes three subtypes: animal phobia, situational±environmental phobia and blood-injection-injury phobia [see Frederikson et al. (1996), Muris et al. (submitteda) who provided evidence for these three separate categories of speci c phobias]. Because speci c fears and phobias are highly prevalent among children (Bernstein et al., 1996), items of all three subtypes were included in the revised SCARED. Thirdly, although obsessive±compulsive disorder and traumatic stress disorder are relatively rare, an extra 13 items were added so that it would also be possible to tap symptoms of these disorders with the revised SCARED. Thus, the nal 66-item revised version of the SCARED purports to measure the symptoms of the entire anxiety disorders spectrum that, according to the DSM-IV, may occur in children. Previous research of our group (Muris et al., in press, 1998) has provided evidence for the concurrent validity of the SCARED-R. For example, SCARED-R scores were found to be positively related to levels of anxiety as indexed by traditional childhood anxiety measures. More speci cally, the SCARED-R total score correlated 0.86 with RCMAS, 0.62 with the FSSC-R and 0.73 with the trait version of the STAIC. The current study examined the factor structure of the SCARED-R in more detail. Normal school children (N = 674) aged between 8 and 13 years completed the questionnaire. The main purpose of the present study was to investigate whether factor analyses would reveal clusters of items that are related to DSM categories in a meaningful way. 2. Method 2.1. Sample 674 children (330 boys and 344 girls) of 8 primary schools in the Maastricht area, The Netherlands, completed the SCARED-R in their classrooms. Ages of the children ranged between 8 and 13 years, with a mean age of 10.28 years (S.D. = 1.22). To enhance the representativeness of the sample, schools were selected from urban (n = 5) and rural (n =3) areas and from low (n = 2), middle (n = 5) and high (n = 1) social class districts. More than 95% of the children were white. Consent to participate was obtained from schools and parents. Approximately 90% of those invited to take part did so. 2.2. Questionnaire The SCARED-R contains 66 items that can be allocated to 9 separate DSM-IV linked subscales: panic disorder, separation anxiety disorder (including school phobia), generalized anxiety disorder, social phobia, speci c phobias (3 types: animal phobia, situational± environmental phobia and blood-injection-injury phobia), obsessive±compulsive disorder and traumatic stress disorder. The anxiety disorders, their essential DSM-IV (APA, 1994) features and the belonging SCARED-R items are shown in Table 1. Children are asked to rate how frequently they have experienced each symptom using a 3-point scale (i.e. 0 = almost never,

102 P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 Table 1 SCARED-R items belonging to the separate DSM-IV de ned anxiety disorders. Mean rating of each item, item-total scale and item-subscale correlations are shown in the right columns Anxiety disorder Key features according to the DSM-IV (APA, 1994) SCARED-R items Mean rating (0±2) Item, total scale correlation Item, subscale correlation$ Panic disorder The presence of recurrent, unexpected panic attacks (APA, 1994, p. 397); a panic attack is a discrete period of intense fear or discomfort that is accompanied by at least 4 somatic or cognitive symptoms (e.g. palpitations, sweating, trembling or shaking, fear of going crazy, fear of dying) (APA, 1994, p. 394) When frightened, it is hard to breathe (1) 0.32 0.42 0.46 When frightened, I feel like passing out (9) 0.17 0.43 0.47 People tell me that I look nervous (14) 0.12 0.23 0.24 When frightened, I feel like going crazy (18) 0.16 0.41 0.47 When frightened, I feel that things are not real (27) 0.31 0.40 0.35 When frightened, my heart beats fast (32) 1.12 0.48 0.38 I feel weak and shaky (35) 0.25 0.40 0.43 When frightened, I sweat a lot (40) 0.38 0.36 0.39 I get really frightened for no reason (44) 0.24 0.47 0.49 When frightened, I feel like I am choking (48) 0.17 0.45 0.56 I am afraid of having anxiety attacks (51) 0.23 0.50 0.50 When frightened, I feel like throwing up (56) 0.22 0.44 0.45 When frightened, I feel dizzy (60) 0.20 0.43 0.47 Separation anxiety disorder (including school phobia) Excessive anxiety concerning separation from the home and from those to whom the person is attached (APA, 1994, p. 110); children with this disorder may be reluctant or refuse to attend school I get scared when I sleep away from home (7) 0.22 0.36 0.39 I follow my parents wherever they go (13) 0.70 0.34 0.34 I worry about sleeping alone (19) 0.28 0.42 0.40 I have nightmares about my parents (29) 0.19 0.39 0.34 I have nightmares about bad happening to me (36) 0.53 0.57 0.42 I am afraid to be alone at home (45) 0.41 0.39 0.42 I don't like being away from my family (50) 0.71 0.44 0.39 I worry that bad happens to my parents (52) 0.82 0.57 0.51 I get headaches or stomach aches when I am at school (3) 0.29 0.28 0.24 I don't like going to school (17) 0.65 0.16 0.25 I worry about going to school (30) 0.20 0.33 0.42 I am scared to go to school (58) 0.12 0.42 0.42 Generalized anxiety disorder Excessive anxiety and worry about a number of events or activities (APA, 1994, p. 432) I worry about others not liking me (8) 0.43 0.41 0.47 I am nervous (11) 0.88 0.41 0.36 I worry about being as good as other kids (21) 0.36 0.47 0.49 I worry about things working out for me (38) 0.38 0.55 0.57 I am a worrier (41) 0.49 0.52 0.53

P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 103 Table 1 (continued ) Anxiety disorder Key features according to the DSM-IV (APA, 1994) SCARED-R items Mean rating (0±2) Item, total scale correlation Item, subscale correlation$ People tell me I worry too much (49) 0.24 0.41 0.49 I worry about the future 0.45 0.43 0.48 I worry about how well I do things (57) 0.41 0.46 0.47 I worry about things that happened in the past (59) 0.42 0.49 0.40 Social phobia Marked and persistent fear of social or performance situations in which embarrassment may occur (APA, 1994, p. 411) I don't like to be with people I don't know (4) 0.85 0.34 0.41 I feel nervous with people I don't know well (15) 0.60 0.42 0.55 I nd it hard to talk with people I don't know (47) 0.65 0.45 0.50 I am shy with people I don't know well (53) 0.76 0.42 0.48 Speci c phobias Marked and persistent fear of a clearly discernable, circumscribed object or situation; exposure to the phobic stimulus almost invariably provokes an immediate anxiety response (APA, 1994, p. 405); subtypes include animals, situational, natural-environment and blood-injection-injury I am afraid of an animal that is not really dangerous (22) 0.32 0.26 0.61 I am so scared of a harmless animal that I do not dare to 0.31 0.32 0.57 touch it (37) I am afraid of an animal that most children do not fear 0.26 0.39 0.54 (65) When I see blood, I get dizzy (5) 0.29 0.27 0.31 I am afraid to visit the doctor (16) 0.28 0.34 0.42 I am afraid to visit the dentist (20) 0.35 0.35 0.39 I am scared when I get an injection (33) 0.56 0.40 0.50 I am afraid to get a serious disease (34) 0.59 0.48 0.32 I feel scared when I watch an operation (42) 1.00 0.40 0.45 I don't like being in a hospital (66) 0.72 0.33 0.37 I am afraid of heights (2) 0.63 0.36 0.36 I get scared when there is thunder in the air (23) 0.39 0.41 0.40 I feel scared when I have to y in an aeroplane (28) 0.39 0.28 0.34 I get scared in small, closed places (61) 0.58 0.56 0.43 I am afraid of the dark (63) 0.48 0.45 0.46 (continued on next page)

104 P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 Table 1 (continued ) Anxiety disorder Key features according to the DSM-IV (APA, 1994) SCARED-R items Mean rating (0±2) Item, total scale correlation Item, subscale correlation$ Obsessive± compulsive disorder Recurrent obsessions and/or compulsions that are severe enough to be time consuming or cause marked distress or signi cant impairment; obsessions are persistent ideas or thoughts that cause marked anxiety or distress; compulsions are repetitive behaviours the goal of which is to prevent or reduce anxiety and distress (APA, 1994, p. 417±418) I want that things are in a xed order (6) 0.45 0.37 0.38 I think that I will be contaminated with a serious disease 0.38 0.37 0.29 (10) I have thoughts that frighten me (12) 0.86 0.54 0.46 I do things more than twice in order to check whether I 0.66 0.35 0.35 did it right (24) I want things to be clean and tidy (26) 0.69 0.23 0.25 I do things to get less scared of my thoughts (31) 0.50 0.49 0.48 I doubt whether I really did something (39) 0.44 0.47 0.44 I fantasize about hurting other people (54) 0.23 0.33 0.27 I have thoughts that I prefer not to have (62) 0.70 0.57 0.47 Traumatic stress disorder Characteristic anxiety symptoms that occur after exposure to an extreme traumatic stress or involving direct personal experience of an event that involves actual or threatened death or serious injury or witnessing an event that involves death, injury or threat to the physical integrity of another person (APA, 1994, p. 424) I have frightening dreams about a very aversive event I once experienced (25) I try not to think about a very aversive event I once experienced (43) I get scared when I think back to a very aversive event I once experienced (46) I have unbidden thoughts about a very aversive event I once experienced (64) 0.61 0.50 0.53 0.72 0.53 0.62 0.60 0.58 0.69 0.54 0.57 0.63 SCARED-R = Screen for Child Anxiety Related Emotional Disorders, Revised. $For the calculation of item-subscale correlations, animal phobia, situational±environmental phobia and blood-injection-injury phobia were considered as separate subscales.

1= sometimes and 2 = often). SCARED-R total score and subscale scores are derived by summing relevant items. 2.3. Procedure Children completed the SCARED-R in their classrooms. The instruction (``A number of statements which refer to children's fears and anxiety are given below. Read each statement and indicate how frequent you have that symptom: almost never, sometimes, or often. There are no right or wrong answers''.) was read aloud by a research assistant while children read along. Children were asked whether they had any questions about the instrument and told that their responses would remain con dential. In the younger classes (ages 8 and 9), SCARED-R items were read aloud as children marked their responses. Older children completed the SCARED-R on their own. A second research assistant or the teacher was always available to assist children who had questions while completing the instrument and to ensure that children worked independently. 2.4. Statistical analysis P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 105 The statistical package SPSS was used to carry out the exploratory factor analyses. For the con rmatory factor analyses, EQS, the structural equations modeling approach (Bentler, 1989), was employed. With this approach, it becomes possible to test plausible alternative models that may underlie a data set. EQS produces a wide range of goodness-of- t indices. In the present study, the following indices were used: (a) chi square divided by degrees of freedom (this value should be about 2.00 or lower; the lower this value, the better the t), (b) the average absolute standardized residuals (AASR; this value should be lower than 0.05; the lower this value, the better the t) and (c) the comparative t index (CFI; this value should be 0.80 or higher for a reasonable t; the higher this value, the better the t). 3. Results 3.1. General results Table 1 also shows the mean ratings for the 66 SCARED-R items. As can be seen, the 10 most frequently reported symptoms were ``When frightened, my heart beats fast'', ``I feel scared when I watch an operation'', ``I am nervous'', ``I have thoughts that frighten me'', ``I don't like to be with people I don't know'', ``I worry that bad happens to my parents'', ``I am shy with people I don't know'', ``I try not to think about a very aversive event I once experienced'', ``I don't like being in a hospital'' and ``I don't like being away from my family''. The 10 most rarely experienced symptoms were ``I am scared to go to school'', ``People tell me that I look nervous'', ``When frightened, I feel like going crazy'', ``When frightened, I feel like I am choking'', ``When frightened I feel like passing out'', ``I have nightmares about my parents'', ``I worry about going to school'', ``When frightened, I feel dizzy'', ``When frightened, I feel like throwing up'' and ``I get scared when I sleep away from home''.

106 P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 Table 2 General statistics (mean scores, Cronbach's alphas, sex di erences, and relationship with age) of the SCARED-R Total group (N = 674) Boys (n = 330) Girls (n = 344) a r with age Total score 30.43 (17.88) 25.63 (16.34) a 35.03 (18.10) b 0.94 0.13$ Panic disorder 3.89 (3.60) 3.13 (3.09) a 4.63 (3.90) b 0.80 0.06 Generalized anxiety disorder 4.05 (3.29) 3.51 (3.06) a 4.58 (3.42) b 0.79 0.01 Social phobia 2.86 (2.00) 2.48 (2.00) a 3.22 (1.94) b 0.70 0.12$ Separation anxiety disorder 5.12 (3.48) 4.34 (3.07) a 5.86 (3.68) b 0.71 0.16$ Obsessive±compulsive disorder 4.89 (3.19) 4.51 (3.20) a 5.26 (3.14) b 0.70 0.10$ Traumatic stress disorder 3.89 (3.60) 3.13 (3.09) a 4.63 (3.90) b 0.80 0.13$ Speci c phobia, animal type 0.89 (1.33) 0.65 (1.15) a 1.13 (1.44) b 0.74 0.11$ Speci c phobia, blood-injection-injury type 3.78 (2.75) 3.11 (2.59) a 4.42 (2.76) b 0.68 0.13$ Speci c phobia, situational±environmental type 2.47 (2.20) 1.91 (1.95) a 3.00 (2.29) b 0.64 0.15$ SCARED-R = Screen for Child Anxiety Related Emotional Disorders, Revised. Means in the same row that do not share the same subscripts di er at P < 0.005. $P < 0.01. General statistics of the SCARED-R are presented in Table 2. Note that the SCARED-R is a reliable instrument in terms of internal consistency. That is, Cronbach's alphas were 0.94 for the total SCARED-R and ranged from 0.64 (situational±environmental phobia) to 0.80 (panic disorder and traumatic stress disorder) for the separate SCARED-R subscales. In line with these satisfactory values, most item-subscale correlations (more than 90%) were well above 0.30 (see Table 1). Furthermore, signi cant sex di erences were found on SCARED-R total score [t(672) = 7.1, P < 0.001], panic disorder [t(648.6, adjusted df ) = 5.5, P < 0.001], generalized anxiety disorder [t(672) = 4.3, P < 0.001], social phobia [t(672) = 4.8, P < 0.001], separation anxiety disorder [t(659.6, adjusted df) = 5.9, P < 0.001], obsessive±compulsive disorder [t(672) = 3.1, P < 0.005], traumatic stress disorder [t(667.5, adjusted df ) = 5.5, P < 0.001], animal phobia [t(650.9, adjusted df) = 4.9, P < 0.001], blood-injection-injury phobia [t(672) = 6.3, P < 0.001] and situational±environmental phobia [t(662.4, adjusted df ) = 6.7, P < 0.001]: girls more frequently reported anxiety disorder symptoms than boys. Finally, small but signi cant, negative correlations were found between age, on the one hand, and most of the SCARED-R scales, on the other hand. This result suggests that anxiety disorders symptoms declined with age. 3.2. Factor structure of the 66-item SCARED-R A principal-components factor analysis with Oblimin rotation (i.e. a rotation which accepts that factors are intercorrelated) was performed on the 66-item SCARED-R. This analysis revealed 17 factors with eigenvalues greater than 1.00. The scree plot, however, clearly suggested a 1-factor solution accounting for 20.5% of the variance (eigenvalues of the rst 17 factors were 13.50, 2.51, 2.23, 2.00, 1.76, 1.68, 1.63, 1.42, 1.38, 1.33, 1.25, 1.17, 1.14, 1.12, 1.09, 1.04 and 1.02). The item-total scale correlations of the 66 SCARED-R items are presented in the right columns of Table 1. As can be seen, 1 item (``I don't like going to school'') correlated

P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 107 Table 3 Results of factor analysis (principal components, oblimin rotation) of the original SCARED (item numbers are given between parentheses) Factor 1 Factor 2 Factor 3 Factor 4 Factor 5 Panic disorder When frightened, it is hard to breathe (1) 0.58 When frightened, I feel like passing out (9) 0.59 People tell me that I look nervous (14) 0.28 0.42 When frightened, I feel like going crazy (18) 0.59 When frightened, I feel that things are not real (27) 0.37 0.44 When frightened, my heart beats fast (32) 0.37 0.42 I feel weak and shaky (35) 0.57 When frightened, I sweat a lot (40) 0.46 I get really frightened for no reason (44) 0.58 When frightened, I feel like I am choking (48) 0.73 I am afraid of having anxiety attacks (51) 0.58 When frightened, I feel like throwing up (56) 0.57 When frightened, I feel dizzy (60) 0.58 Generalized anxiety disorder I worry about others not liking me (8) 0.61 I am nervous (11) 0.38 0.40 I worry about being as good as other kids (21) 0.60 I worry about things working out for me (38) 0.67 I am a worrier (41) 0.63 People tell me I worry too much (49) 0.61 I worry about the future (55) 0.66 I worry about how well I do things (57) 0.57 I worry about things that happened in the past (59) 0.41 0.48 Social phobia I don't like to be with people I don't know (4) 0.61 I feel nervous with people I don't know well (15) 0.74 I nd it hard to talk with people I don't know (47) 0.67 I am shy with people I don't know well (53) 0.69 School phobia I get headaches or stomach aches when I am at school (3) 0.50 I don't like going to school (17) 0.32 I worry about going to school (30) 0.53 0.39 I am scared to go to school (58) 0.53 0.38 Separation anxiety disorder I get scared when I sleep away from home (7) 0.48 I follow my parents wherever they go (13) 0.46 I worry about sleeping alone (19) 0.61 I have nightmares about my parents (29) 0.29 I have nightmares about bad happening to me (36) 0.46 0.25 I am afraid to be alone at home (45) 0.66 I don't like being away from my family (50) 0.49 0.38 I worry that bad happens to my parents (52) 0.57 0.42 Eigenvalue 8.45 1.91 1.86 1.47 1.32 % Explained variance 22.22 5.03 4.89 3.88 3.47 SCARED = Screen for Child Anxiety Related Emotional Disorders.

108 P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 <0.20 with total SCARED-R score, 6 items correlated <0.30, whereas the remaining 59 items all correlated substantially (i.e. >0.30) with total SCARED-R. A second order factor analysis (in which SCARED-R subscales scores are factor analyzed) also pointed in the direction of a 1-factor solution: only 1 factor with an eigenvalue greater than 1.00 (i.e. 4.87) emerged. This factor accounted for 52.06% of the variance. Taken together, the results of exploratory factor analysis suggest that in this sample of normal children, the SCARED-R possesses a 1-factor structure. Con rmatory factor analyses were carried out to further examine the factor structure of the SCARED-R. Three alternative models were investigated. The rst model examined the degree to which all symptoms can be viewed as re ecting a single, homogeneous dimension of anxiety rather than a number of anxiety clusters (the 1-factor model). The second model postulated that the data would be explained by nine independent factors (the 9-uncorrelated-factors model). The third and nal model also assumed 9 separate factors but allowed these factors to be intercorrelated (the 9-correlated-factors model). Results of the con rmatory factor analyses revealed the following goodness-of- t values for the 1-factor model: chi square/df = 2.96, AASR = 0.04 and CFI = 0.66. For the 9-uncorrelated factors model, these values were: chi square/df = 3.48, AASR = 0.15 and CFI = 0.56. For the 9-correlated factors model, values were: chi square/df = 2.26, AASR = 0.05 and CFI = 0.78. These results, in particular the insu cient CFIs, indicate that none of the models provided a satisfactory t to the SCARED-R data. 3.3. Factor structure of the original 38-item SCARED An additional principal components factor analysis with Oblimin rotation was conducted on the 38 items of the original SCARED. Again, a very strong rst factor emerged, together with 4 other factors with eigenvalues greater than 1.00. Table 3 displays the 38 SCARED items and their loadings on these 5 factors after rotation. As can be seen, most items loaded convincingly on their supposed factor. Together, these ve factors accounted for 39.49% of the variance. Thus, in this sample of normal children, the factor structure of the original 38-item SCARED (Birmaher et al., 1997) was replicated. A con rmatory factor analysis revealed that a 5-correlated-factors model provided the best t for the original SCARED. Goodness-of- t indices were all satisfactory: chi square/df = 2.45, AASR = 0.04 and CFI = 0.84. 3.4. Factor structure of the new SCARED-R speci c phobia scales A nal factor analysis was carried out on the 15 items of the SCARED-R that intend to measure speci c phobias. Results revealed three factors with eigenvalues greater than 1.00, declaring 44.37% of the variance. Table 4 shows SCARED-R speci c phobia items and their loadings on the 3 factors. As expected, blood-injection-injury type items loaded convincingly on the rst factor, animal type items on the second factor and situational±environmental type items on the third factor. A con rmatory factor analysis indeed showed that the 3-factor model of the SCARED-R speci c phobia items was satisfactory: chi square/df = 2.98, AASR = 0.04 and CFI = 0.90.

P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 109 Table 4 Results of factor analysis (principal components, oblimin rotation) of the new SCARED-R speci c phobia scales (item numbers are given between parentheses) Factor 1 Factor 2 Factor 3 Speci c phobia, blood-injection-injury type When I see blood, I get dizzy (5) 0.38 I am afraid to visit the doctor (16) 0.74 I am afraid to visit the dentist (20) 0.66 I am scared when I get an injection (33) 0.75 I am afraid to get a serious disease (34) 0.36 0.40 I feel scared when I watch an operation (42) 0.51 0.47 I don't like being in a hospital (66) 0.54 Speci c phobia, animal type I am afraid of an animal that is not really dangerous (22) 0.85 I am so scared of a harmless animal that I do not dare to touch it (37) 0.81 I am afraid of an animal that most children do not fear (65) 0.76 Speci c phobia, situational±environmental type I am afraid of heights (2) 0.56 I get scared when there is thunder in the air (23) 0.65 I feel scared when I have to y in an aeroplane (28) 0.57 I get scared in small, closed places (61) 0.66 I am afraid of the dark (63) 0.67 Eigenvalue 3.98 1.54 1.22 % Explained variance 25.97 10.29 8.11 SCARED-R = Screen for Child Anxiety Related Emotional Disorders, Revised. 4. Discussion The current study investigated the factor structure of the SCARED-R in a sample of normal school children aged 8±13 years. Results of an exploratory factor analysis suggest that the 66- item SCARED-R primarily has a 1-factor structure. By means of con rmatory factor analysis, several models for the SCARED-R (i.e. 1-factor model, 9-uncorrelated-factors model and 9- correlated-factors model) were tested. However, none of these models was found to be satisfactory. Additional exploratory and con rmatory factor analyses carried out on parts of the SCARED-R provided some support for the presence of a number of anxiety symptoms clusters. To begin with, with the 38 original SCARED items the 5-factor structure (re ecting the anxiety categories of panic disorder, generalized anxiety disorder, separation anxiety disorder, social phobia and school phobia) as found by Birmaher et al. (1997) was replicated, in spite of the fact that the latter study relied on a clinical sample. Furthermore, factor analysis performed on the speci c phobia items of the SCARED-R revealed three factors that t with the subtypes that are listed in the DSM-IV (APA, 1994; see also Frederikson et al., 1996). Thus, as intended, SCARED-R speci c phobia items can be grouped into three subscales, namely blood-injection-injury phobia, animal phobia and situational±environmental phobia.

110 P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 The present studies failed to nd a satisfactory factor structure for the complete SCARED- R. More speci cally, both exploratory and con rmatory factor analysis did not yield the expected 9 factors representing the anxiety disorders spectrum as de ned in the DSM. One could argue that this negative result is due to the fact that the present study relied on a sample of normal children. It is still possible that in samples of clinically referred children, the hypothesized DSM-like factor structure of the SCARED-R will emerge. Future studies should address this issue. Furthermore, it should be noted that a good factor structure is not a conditio sine qua non of a measure's validity. The SCARED-R is closely linked to clinical practice which increasingly relies on the DSM for classifying anxiety and other mental disorders in children. Frequently employed childhood anxiety measures such as the STAIC, the RCMAS, and the FSSC-R do not have this direct link to DSM-de ned diagnostic categories. Not surprisingly then, research has frequently shown that these traditional indices lack discriminant validity. That is, these questionnaires are unable to di erentiate between anxiety disordered children and children with other types of psychopathology (e.g. Perrin and Last, 1992). The SCARED-R is promising in this respect in that it seems to possess adequate discriminant validity. Evidence for this comes from two sources. First, Birmaher et al. (1997) found that the original SCARED di erentiates between anxiety disordered children, children with depression, and children with disruptive disorders. Second, there is evidence to suggest that the SCARED-R satisfactorily discriminates children with a speci c anxiety disorder from children without that particular anxiety disorder (Muris et al., submittedb). Using the SCARED-R in a sample of normal children, the current study replicated some phenomena that previous surveys (relying on other instruments) have found to be very robust. First, as in other studies, girls were found to have higher anxiety scores than boys (see, for a review, Bernstein and Borchardt, 1991). Furthermore, age was inversely related to SCARED-R scores. Again, this is in agreement with earlier studies that showed that anxiety symptoms decline with age. In the present study, this age e ect was most evident for separation anxiety disorder symptoms. Birmaher et al. (1997) also showed that especially separation anxiety symptoms are more common among younger children than among older children. Note that the present ndings (and those of Birmaher et al., 1997) suggest that school phobia can best be treated as a distinct anxiety disorder. Although it is generally assumed that this type of phobia is predominantly linked to separation anxiety disorder (e.g. DSM-III-R; APA, 1987), several authors (Ollendick and Mayer, 1984; Atkinson et al., 1985; Bernstein and Gar nkel, 1986; Last and Francis, 1988) have noted that refusal to go to school can also point in the direction of fear of a speci c stimulus in the school setting (which would suggest the presence of a speci c phobia) and/or fear of certain social situations such as speaking in class (which would suggest the presence of social phobia). What do the present ndings mean for the use of the SCARED-R? Clearly, the original SCARED (comprising the subscales panic disorder, separation anxiety disorder, generalized anxiety disorder, social phobia, and school phobia) has reasonable psychometric properties and, consequently, seems to be an acceptable clinical or research tool. The same is true for the added speci c phobias scales of the SCARED-R. However, more research is required with regard to the traumatic stress disorder and the obsessive±compulsive disorder subscales of the SCARED-R. Although the traumatic stress disorder subscale might be valuable in clinical settings, more information is needed about what precisely this scale measures. For example,

P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 111 what type of experiences do children refer to when they respond with ``sometimes'' or ``often'' to items such as ``I get scared when I think back of a very aversive event I once experienced''? Much the same is true for the SCARED-R obsessive±compulsive disorder subscale. Future studies should compare this subscale with other instruments that measure this disorder in children, e.g. the child version of the Leyton Obsessional Inventory (LOI; Berg et al., 1986). References APA (1987). Diagnostic and statistical manual of mental disorders (3rd ed. revised) (DSM-III-R). Washington, DC: American Psychiatric Association. APA (1994). Diagnostic and statistical manual of mental disorders (4th ed.) (DSM-IV). Washington, DC: American Psychiatric Association. Atkinson, L., Quarrington, B., Cyr, J. J., & Atkinson, F. V. (1985). Di erential classi cation in school refusal. British Journal of Psychiatry, 155, 191±195. Bell-Dolan, D. J., Last, C. G., & Strauss, C. C. (1990). Symptoms of anxiety disorders in normal children. Journal of the American Academy of Child and Adolescent Psychiatry, 29, 759±765. Bentler, P. M. (1989). EQS: Structural equations program manual. Los Angeles: BMDP Statistical Software Inc. Berg, C. J., Rapoport, J. L., & Flament, M. (1986). The Leyton Obsessional Inventory: Child Version. Journal of the American Academy of Child and Adolescent Psychiatry, 25, 84±91. Bernstein, G. A., & Borchardt, C. M. (1991). Anxiety disorders of childhood and adolescence: A critical review. Journal of the American Academy of Child and Adolescent Psychiatry, 30, 519±532. Bernstein, G. A., Borchardt, C. M., & Perwien, A. R. (1996). Anxiety disorders in children and adolescents: A review of the past 10 years. Journal of the American Academy of Child and Adolescent Psychiatry, 35, 1110±1119. Bernstein, G. A., & Gar nkel, B. D. (1986). School phobia: The overlap of a ective and anxiety disorders. Journal of the American Academy of Child and Adolescent Psychiatry, 25, 235±241. Birmaher, B., Khetarpal, S., Brent, D., Cully, M., Balach, L., Kaufman, J., & McKenzie Neer, S. (1997). The Screen for Child Anxiety Related Emotional Disorders (SCARED): Scale construction and psychometric characteristics. Journal of the American Academy of Child and Adolescent Psychiatry, 36, 545±553. Costello, E. J. & Angold, A. (1995). Epidemiology. In J. S. March (Ed.), Anxiety disorders in children and adolescents. New York: Guilford Press. Frederikson, M., Annas, P., Fischer, H., & Wik, G. (1996). Gender and age di erences in the prevalence of speci c fears and phobias. Behaviour Research and Therapy, 34, 33±39. Last, C. G. & Francis, G. (1988). School phobia. In B. B. Lahey & A. E. Kazdin (Eds.), Advances in clinical child psychology. New York: Plenum Press. March, J. S., Parker, J., Sullivan, K., Stallings, P., & Conners, K. (1997). The Multidimensional Anxiety Scale for Children (MASC): Factor structure, reliability, and validity. Journal of the American Academy of Child and Adolescent Psychiatry, 36, 554±565. Muris, P. (1997). The Screen for Child Anxiety Related Emotional Disorders (revised version). Maastricht: Maastricht University, Department of Psychology. Muris, P., Merckelbach, H., Van Brakel, A., Mayer, B. & Van Dongen, L. (1998). The Screen for Child Anxiety Related Emotional Disorders: Relationship with anxiety and depression in normal children. Personality and Individual Di erences, 24, 451±456. Muris, P., Merckelbach, H., Mayer, B. & Prins, E. (submittedb). How serious are common childhood fears? Exploring the severity of fears in normal children by means of a structured anxiety disorders interview. Muris, P., Merckelbach, H., Mayer, B., Van Brakel, A. & Thissen, S. (in press). The Screen for Child Anxiety Related Emotional Disorders and its relationship to traditional childhood anxiety measures. Journal of Behavior Therapy and Experimental Psychiatry. Muris, P., Schmidt, H. & Merckelbach, H. (submitteda). The structure of speci c phobia symptoms among children and adolescents. Ollendick, T. H. (1983). Reliability and validity of the Revised Fear Survey Schedule for Children (FSSC-R). Behaviour Research and Therapy, 23, 465±467. Ollendick, T. H. & Mayer, J. A. (1984). School phobia. In S. M. Turner, Behavioral theories and treatment of anxiety. New York: Plenum Press. Perrin, S., & Last, C. G. (1992). Do childhood anxiety measures measure anxiety?. Journal of Abnormal Child Psychology, 20, 567±578. Reynolds, C. R., & Richmond, B. O. (1978). What I think and feel: A revised measure of children's manifest anxiety. Journal of Abnormal Child Psychology, 6, 271±280.

112 P. Muris et al. / Personality and Individual Di erences 26 (1999) 99±112 Spence, S. H. (1997). Structure of anxiety symptoms among children: A con rmatory factor-analytic study. Journal of Abnormal Psychology, 106, 280±297. Spielberger, C. D. (1973). Manual for the State-Trait Anxiety Inventory for Children. Palo Alto, CA: Consulting Psychologists Press.