What Do Youth Referred for Anxiety Problems Worry About? Worry and Its Relation to Anxiety and Anxiety Disorders in Children and Adolescents

Transcription

1 Journal of Abnormal Child Psychology, Vol. 28, No. 1, 2000, pp What Do Youth Referred for Anxiety Problems Worry About? Worry and Its Relation to Anxiety and Anxiety Disorders in Children and Adolescents Carl F. Weems, 1 Wendy K. Silverman, 1,3 and Annette M. La Greca 2 Received December 15, 1998; revision received May 17, 1999; accepted July 4, 1999 This study examined worry and the parameters of worry that may be associated with clinical anxiety in a sample of 119 children and adolescents referred to a childhood anxiety disorders specialty clinic. Using an interviewing procedure, results indicated that the types of worries reported by the children were similar to those reported in previous studies of nonreferred community children. Also similar to previous community studies were findings showing moderate but significant correlations between different indices of worry (i.e., number, intensity, and frequency of the worries) and children s scores on self-rating scales of anxiety. Results further indicated that worry contributed additional variance beyond that of anxiety in predicting fear. In addition, intensity differentiated clinic children s worries from nonreferred children s. Intensity and number of worries differentiated subsamples of children within the clinic-referred sample (i.e., children with overanxious disorder or generalized anxiety disorder and children with simple phobia). The importance of examining children s worries to further understand anxiety and its disorders in youth is discussed. KEY WORDS: Worry; youth; anxiety. What do children worry about? This question was asked recently by Silverman, La Greca, and Wasserstein (1995), and answers were provided on the basis of a large sample of 273 schoolchildren ages 7 to 12 years. The results provided important normative information about the worries of schoolchildren as well as initial information about the relation between the constructs of anxiety and worry. Silverman et al. (1995) used an interviewing procedure to ask children about their worries in 14 different areas. For each worry reported, further queries were made regarding specific worries in each area, and their frequency and intensity. An average number of 7.64 worries were reported about a wide range of topics. The children reported the most number of worries about health, school, and per- 1 Florida International University, Miami, Florida. 2 University of Miami, Coral Gables, Florida. 3 Please address all correspondence to Dr. Wendy K. Silverman, Child and Family Psychosocial Research Center, Department of Psychology, Florida International University, University Park, Miami, FL 33199; silverw@fiu.edu. sonal harm; they worried most frequently about family, classmates, and friends; and they worried most intensely about war, money, and disasters. Results also indicated that children s worries were significantly but moderately correlated with several measures of anxiety. Other community studies have provided similar results (Henker, Whalen, & O Neil, 1995; Muris, Meesters, Merckelbach, Sermon, & Zwakhalen, 1998). Henker et al. (1995), for example, used an interview designed to assess worries and health and environmental risk perceptions among a community sample of 194 children in grades 4 through 8. Results indicated that children worried about a variety of topics including personal issues such as grades and social relations, as well as issues such as death and broader social concerns (e.g., homelessness and the environment). Muris et al. (1998) also collected worry data from 193 schoolchildren ages 8 to 13 years and, similar to Silverman et al. (1995), found that common worries concerned school, health, dying and illness, and social issues. In addition to studying community samples, it is important to examine worry in samples of clinic-referred /00/ $18.00/0 C 2000 Plenum Publishing Corporation

2 64 Weems, Silverman, and La Greca anxious children. Worry has been and continues to be a central component of several anxiety disorders as described by the Diagnostic and Statistical Manual of Mental Disorders [DSM; American Psychiatric Association (APA), 1987, 1994]. Of all the anxiety disorders described in the DSM, the role of worry is portrayed as being most prominent in the disorder that was referred to as overanxious disorder (OAD) in DSM-III-R (APA, 1987), and generalized anxiety disorder (GAD) in the subsequent version, DSM-IV (APA, 1994). Despite the prominent role of worry in the DSM description of OAD/GAD, empirical evidence regarding the role that worry plays in these disorders in youth has only begun to emerge (e.g., Chorpita, Tracey, Brown, Colluca, & Barlow, 1997; Muris et al., 1998; Perrin & Last, 1997). Overall, the results from these studies suggest that worry is prominent among children with anxiety disorders. For example, Chorpita et al. (1997) reported the results of a study aimed at developing a downscaled version of the Penn State Worry Questionnaire. Containing items such as I find it easy to stop worrying when I want, Chorpita et al. examined the scale s psychometric properties in a community sample (n = 199; ages 6 to 18 years) and found it to be satisfactory. In a second study, scores on the scale were compared among a small sample of clinicreferred children who met DSM diagnostic criteria for GAD (n = 14) with children who met criteria for other anxiety disorders (n = 10) and with normal control subjects (n = 10). Children with GAD scored significantly higher than the other groups, children with other anxiety disorders were in the middle, and the controls had the lowest scores (Chorpita et al., 1997). In the Muris et al. (1998) study mentioned earlier, 6.7% (n = 13) of the children in the community sample were found to meet DSM-III-R diagnostic criteria for either OAD or GAD. These children s main intense worry was identified via interview, followed by questioning about the frequency, interference, and controllability of this intense worry. The findings indicated that these children s main intense worry was more frequent, more interfering, and less controllable than the main intense worry reported by the children who did not meet criteria for either OAD or GAD. In an investigation using a sample of clinic-referred anxiety-disordered children (ages 5 to 13 years), Perrin and Last (1997) developed a 31-item worry measure that covered the types of worries that characterize several anxiety disorders (i.e., OAD, avoidant disorder, separation anxiety disorder, and social phobia). Two indices, Total Number of Worries and Total Number of Intense Worries, were derived and their relations to several anxiety selfreport measures were examined. Both indices were found to be moderately to strongly correlated with the anxiety measures (r =.13 to.72). In addition, the Total Number of Intense Worries was significantly greater in children meeting diagnostic criteria for anxiety disorders (n = 72) than in children never psychiatrically ill (n = 55). Interestingly, the Total Number of Worries was not significantly different between the two groups. The present study builds upon this previous research on worry in youth in several ways. First, this study examined the content of worries reported by children clinicreferred for anxiety problems. Although the content of children s worries has been examined in community samples, it has not been examined in a sample of clinic-referred anxiety-disordered children (Henker et al., 1995; Muris et al., 1998; Silverman et al., 1995). 4 Obtaining descriptive information about the types of worry reported by children who are clinic-referred for anxiety-disorders would help in discerning whether these children tend to worry about similar or different things than nonreferred children. Second, the incremental validity of worry in predicting children s fears beyond that predicted by anxiety was examined. This was studied because although evidence exists to provide support for the notion that worry and anxiety are related constructs [i.e., the relation of indices of worry and anxiety self-report measures have been examined in community (Chorpita et al., 1997; Muris et al., 1998; Silverman et al., 1995) and in clinic samples (Perrin & Last, 1997), and significant correlations have been found], it has not been determined whether worry indices predict variance in another construct, such as children s fears, beyond that predicted by self-report measures of anxiety. That is, given the overlap between worry and anxiety, questions can be raised about whether these constructs are distinctive in youth. Thus, assessing the incremental validity of worry would help in discerning whether worry is distinctive from anxiety (Borkovec, Shadick, & Hopkins, 1991). Finally, although previous studies show that worry plays a role in anxiety and its disorders in youth, particularly in OAD/GAD (e.g., Chorpita et al., 1997; Muris et al., 1998; Perrin & Last, 1997), what remains unclear is what it is about worry that is associated with clinical dysfunction. That is, what distinguishes normal or nonclinical/dysfunctional worry from clinical worry such as that found in OAD/GAD? For example, as noted, Muris et al. (1998) found that the frequency, level of interference, and controllability of children s main intense 4 Although Perrin and Last (1997) examined content, their examination of content was based on a closed-response format and the items on their worry measure were derived from the DSM s descriptions of several anxiety disorders.

3 Worry in Youth 65 worry differentiated diagnosable cases of either OAD or GAD from the rest of the sample. Perrin and Last (1997) found that although the total number of worries did not differentiate children with anxiety disorders from children with no anxiety disorders, the total number of intense worries did differentiate these two groups. The goal of this study was to obtain a better grasp of the aspects of worry that are associated with impairment and thus render worry pathological. This was done in two ways. One was by examining the type, number, frequency, and intensity of worries reported by a sample of children referred to an anxiety-disorders specialty clinic and comparing this clinic sample s worries to the worries reported by the nonclinical sample of Silverman et al. (1995). A second way was by comparing the expression of worry in terms of the type, number, frequency, and intensity in two subsamples within the anxiety-disordered sample: children with either OAD or GAD versus children with simple or specific phobia. 5 These two specific subsamples were compared because of their differences with respect to worry. Specifically, as noted earlier, worry plays a very prominent role in the DSM description of OAD/GAD. Simple phobia, on the other hand, perhaps more than any of the anxiety disorders, involves a negligible role for worry in the DSM description. Rather, simple phobia is characterized by a circumscribed fear of a specific object or event (APA, 1994). By comparing these two subsamples of children, we were interested in discerning the aspects of worry that differentiate OAD/GAD in children from simple phobia in children. We asked: Is it the number, frequency, or intensity of worry or all three that differentiate the two disorders? Moreover, we asked: Are the number, frequency, or intensity of worry differentially linked to self-ratings of anxiety in these two subsamples of anxiety-disordered children? Is it the case, for example, that the worry that characterizes children with OAD/GAD is more strongly associated with anxiety than the worry of children with simple phobias? METHOD Participants The sample comprised 119 children and adolescents (from hereon referred to as children) who presented to 5 During a portion of the time that this study was being conducted, data were collected while DSM-III-R was in place. In this paper, we use the term simple phobia to refer to children diagnosed as either having simple phobia with DSM-III-R or specific phobia with DSM-IV. We use the term OAD/GAD to refer to children diagnosed with either disorder with DSM-III-R or GAD with DSM-IV. the Child Anxiety and Phobia Program housed within the Child and Family Psychosocial Research Center of Florida International University, Miami. Both the child and the parent, usually the mother, participated in the assessment procedures. The sample comprised 49 girls and 70 boys with a mean age of 9.91 years, and an age range of 6 to 16 years. Fifty-seven percent of participants were European-American, 39% were Hispanic American, 3% were African American, 1% were of other ethnic backgrounds. The range of the participants family income was as follows: Zero to $19,999 (21%), $20,000 to $40,000 (32%), above $40,000 (37%); 10% did not report their income. All families were either self-referred in response to clinic publicity or were referred by pediatricians, school psychologists, or other mental health professionals. All of the children in this sample were referred to the program because of difficulties with fear and/or anxiety. Children met diagnostic criteria for the following disorders: simple phobia (n = 46), OAD/GAD (n = 26), social phobia (n = 18), and separation anxiety disorder (n = 16), agoraphobia without panic (n = 4), panic disorder with agoraphobia (n = 2), obsessive-compulsive disorder (n = 2), and avoidant disorder (n = 1). All but four children in the sample met DSM criteria for a primary anxiety or phobic disorder. Of the children who did not meet criteria for a primary anxiety disorder, two were referred for anxiety but did not meet diagnostic criteria for any disorder, one child received a primary diagnosis of depression, and the other child received a primary diagnosis of oppositional defiant disorder. Comorbid secondary diagnoses in this sample were common. Only 13% of the sample did not meet criteria for a secondary diagnosis. The most frequently diagnosed secondary diagnoses were: OAD/GAD (22%), simple phobia (21%), separation anxiety disorder (14%), attention-deficit hyperactivity disorder (8%), avoidant disorder (7%), and social phobia (4%). Secondary disorders diagnosed to a lesser extent were (16% of total): affective disorders (major depression, dysthymia), posttraumatic stress disorder, oppositional defiant disorder, agoraphobia, and panic disorder. For the subsample comparisons, groups were formed on the basis of primary diagnoses. Specifically, children with either a primary diagnosis of OAD or GAD were compared with children with a primary diagnosis of simple or specific phobia. Chi-square analyses and t tests revealed no significant differences between these two diagnostic groups in terms of age, ethnicity, income level, or gender. Nor were there any differences between these two groups and the rest of the sample on any of the sociodemographics. Secondary diagnosis overlap also was not pervasive

4 66 Weems, Silverman, and La Greca between the two groups: only five children with a primary diagnosis of OAD/GAD had secondary simple phobias and only six children with a primary diagnosis of simple phobia had secondary diagnoses of OAD/GAD. Because comorbidity is generally high in clinical samples, in the interest of external validity, these cases were retained in the analyses. In addition, chi-square analyses revealed that the OAD/GAD and simple phobia groups did not display differential proportions of any type of secondary diagnoses. Self-Report Measures Revised Children s Manifest Anxiety Scale (RCMAS; Reynolds & Richmond, 1978) The RCMAS is a widely used 37-item scale designed to assess general anxiety in children. Twenty-eight items are summed to yield a Total Anxiety score. The RCMAS also yields three factor subscales: Worry-Oversensitivity, Physiological, and Concentration. The other nine items comprise the Lie subscale. The RCMAS has been found to have satisfactory reliability and validity estimates (e.g., Reynolds & Richmond, 1978). State Trait Anxiety Inventory for Children Trait Version (STAIC-T; Speilberger, 1973) The Trait version of the STAIC is a 20-item selfreport measure of stable anxious symptoms in children. The STAIC is a widely used, well-researched measure with satisfactory reliability and validity estimates (Speilberger, 1973). Social Anxiety Scale for Children Revised (SASC-R) and Social Anxiety Scale for Adolescents (SAS-A) (La Greca & Lopez, 1998; La Greca & Stone, 1993) The SASC-R and SAS-A are designed to measure social anxiety in situations involving peers. Each of the 18 items (plus 4 filler items) is rated on a 5-point scale according to how true the item is for the child or adolescent. The SASC-R and SAS-A have three factor subscales: Fear of Negative Evaluation (FNE), Social Avoidance and Distress in General (SAD General), and Social Avoidance and Distress Specific to New Situations or New Peers (SAD New). The SASC-R and SAS-A have been shown to have good reliability and validity estimates in both clinically anxious and community samples (Ginsburg, La Greca, & Silverman, 1998; La Greca & Lopez, 1998; La Greca & Stone, 1993). Childhood Anxiety Sensitivity Index (CASI; Silverman, Fleisig, Rabian, & Peterson, 1991) The CASI is an 18-item self-report measure designed to assess children s fear of different symptoms of anxiety. Children rate each question by selecting one of three choices: None, Some, or A lot. Example questions are It scares me when I feel shaky and It scares me when I feel nervous. This measure was modeled after the adult Anxiety Sensitivity Index (Peterson & Reiss, 1987) and tailored for use with children ages 6 to 17 years. The CASI has been shown to have satisfactory reliability estimates (Silverman et al., 1991) and to be a valid measure of anxiety sensitivity in both children and adolescents (Weems, Hammond-Laurence, Silverman, & Ginsburg, 1998). Revised Fear Survey Schedule for Children (FSSC-R; Ollendick, 1983) The FSSC-R is a widely used 80-item fear inventory designed to assess the frequency, intensity, and types of fears of children. Children are asked to rate how afraid they are of 80 objects and situations (e.g., snakes, being alone, dark places ) using a 3-point scale: None, Some, or A lot. The FSSC-R has been shown to have high test retest reliability and convergent validity (Ollendick, 1983). The total fear score was used in this investigation. Procedure The assessment procedures were conducted in two separate testing sessions. The first session lasted approximately 2 hr and the second session, which occurred approximately 1 week after the first, lasted approximately 1 hr. In the first session, diagnostic and self-report measures were administered to children and parents. In the second session, information about worries was collected from the children. More specifically, in the first session, the Anxiety Disorders Interview Schedule for Children (ADIS-C and ADIS-P, respectively; Silverman & Nelles, 1988) was administered to all referred children and parents. The ADIS-C and ADIS-P are structured interviews that emphasize the anxiety disorders. The interviews permit the clinician to assess and diagnose other major childhood disorders, including the externalizing and affective disorders, according to DSM criteria. All diagnostic interviews were conducted by either the program director (W.K.S.), a postdoctoral psychologist, or advanced doctoral students in psychology. Diagnosticians were trained by observing live and videotaped

5 Worry in Youth 67 interviews. Initial discrepancies were discussed to reach agreement in training sessions. All diagnosticians had to meet reliability criteria of 100% agreement on five child parent interviews before conducting an interview by themselves. In cases of multiple diagnoses, the relative impact or interference of each diagnosis was used for ascertaining the primary diagnosis, the secondary diagnosis, etc., as delineated in the ADIS-C/P guide (see Albano & Silverman, 1996). A subsample of the participants comprised the samples in previous reliability studies (i.e., Silverman & Eisen, 1992; Silverman & Rabian, 1995). These studies demonstrated good to excellent test retest reliability. For example, kappas were.84 for simple phobia and.64 for OAD. At the second session, an open-format-structured interview designed to assess children s worries was conducted. Fourteen areas of worry were assessed: School, Performance, Classmates, Friends, War, Disasters, Money, Health, Future Events, Personal Harm, Little Things, Appearance, Family, and Other worries not covered by previous areas. Children were asked about their worries in each specific area. For example, children were asked Do you worry about school? If the response was yes, they were asked what specific things about school they worried about. Children s responses were written down on the interview. For each specific worry reported in an area, the children were asked to make the following ratings: how much (i.e., intensity) he or she worried about the item on a 5-point scale (0 = none,1= a little bit,2=some,3=a lot, 4=very very much) and how often (i.e., frequency) he or she worried about the item (0 = none, 1=some, 2=a lot). A visual prompt, namely a Worry Thermometer, was used to facilitate the children s understanding of the ratings to be made as well as to help the children anchor their ratings. Considerable care was used in explaining and describing the rating scales to the children and particular attention was paid to ensure that the children comprehended the distinctions being drawn by the different rating scales. To further ensure the children s understanding of the rating tasks, several practice items were provided, which the children rated and then discussed their responses with the experimenter. Any misconceptions (which were few) were rectified at this time. The worry interview was administered by either the program director, a postdoctoral psychologist, or advanced doctoral students in psychology trained in the administration of the interview. In the present study, specific worries reported by the children were written down verbatim on the interview and then were coded independently by two trained research assistants blind to the hypotheses of the study and diagnoses of the children. The coders were provided with a list of the 14 areas of worry that also included a set of numeric codes for specific worries that were developed by Silverman et al. (1995). Prior to the coders use of the categories and specific areas of worry derived by Silverman et al. (1995), the present authors carefully reviewed the clinic sample s responses. Because the responses of the clinic sample were highly similar to those found in the previous community sample, the decision was made to use the same categories and areas of worries and to code any worries that did not fit as Other worries. This decision also allowed for a more direct comparison between the current sample s data with the community sample of Silverman et al. Interrater agreement for each of the 67 specific worries reported in this sample was above 80%, with most agreement above 90%. In addition, Cohen s kappa was computed for all specific worries with n > 10. The minimum kappa was.79, with an average kappa of.93. Interrater agreement for all worry areas (e.g., School, Performance, Classmates) was above 96% (kappas ranged from.95 to 1.00). Test retest reliability of children s reports of worry for the total number of worries and for the total number of areas of worry has been found to be r =.75 and r =.78, respectively (Silverman et al. 1995). Support for validity comes from the significant correlation found between the indices of the worry interview with the Worry/Oversensitivity subscale of the RCMAS [.41 in Silverman et al. (1995) and.44 in the present study]. In addition to examining the areas of worry and specific worries reported, several worry indices were calculated from the interview responses. Specifically, the number of specific worries, the average intensity of worry, and the average frequency of worry within each of the 14 worry categories were computed. When children reported more than one worry response for an area, the intensity and frequency were averaged across their responses (e.g., if a child indicated that he or she specifically worried about operations and also about AIDS under the Health category, mean intensity and frequency ratings were computed). In addition, for each child, the number of areas of worry was computed as well as the total number of worries across the areas of School, Performance, Classmates, and so on. Further, to examine the relations among worry, anxiety, and fear, the total number of worries (across each of the 14 areas) for each child was used, and summary intensity and frequency scores were computed. Specifically, a summary intensity score was computed that was the sum of the child s intensity ratings divided by the total number of worries. A summary frequency score also was computed that was the sum of the child s frequency ratings divided by the total number of worries.

6 68 Weems, Silverman, and La Greca RESULTS Overview of Sample Responses Children in the sample reported an average number of 5.74 worries (SD = 5.1, range 0 21) and their worries spanned an average of 4.82 areas (SD = 2.90, range 0 13). Table I presents a summary of children s worry responses for each area. As Table I shows, children reported the most number of worries in the areas of Health, School, Disasters, Personal Harm, and Future Events. Table I also presents the average intensity and frequency of the worries that were reported in each area. The most intense worries were in the War, Personal Harm, Disasters, School, and Family areas. The most frequent worries were in the Friends, Classmates, School, Health, and Performance areas (see Table I). Supplemental analyses were conducted to examine the role of several sociodemographic variables (age, gender, income, and ethnicity) on the number, intensity, and frequency of worries as well as the average number of worries for each of the specific worry areas. In terms of age, the responses of children in the age groups of 6 to 8 years, 9 to 11 years, and 12 to 16 years were compared using Table I. Summary of Worries No. of No. of Intensity Frequency/ Area responses a children a of worry b event b Health 91 (1) 61 (1) 2.62(1.08) c,d 0.86(.70) School 88 (2) 54 (2) 2.68(.89) c,d 0.87(.68) Disasters 71 (3) 54 (3) 2.72(1.09) c,d 0.65(.44) c,e Personal Harm 68 (4) 45 (5) 3.01(.99) c,d 0.33(.55) d, f Future Events 61 (5) 46 (4) 2.53(1.10) c,d 0.56(.63) f,g Classmates 51 (6) 30 (9) 2.26(1.02) 0.89(.63) f,g Performance 43 (7) 36 (6) 1.99(.93) 0.73(.69) Family 40 (8) 35 (7) 2.63(1.18) c,g 0.68(.70) Money 32 (9) 31 (8) 2.32(1.08) 0.54(.64) Other Worries h 29 (10) 22 (12) 3.09(1.07) c,d 0.90(.85) War 28 (11) 27 (10) 3.02(1.11) c,e 0.10(.35) d, f Little Things 28 (12) 25 (11) 2.02(.77) c,g 0.54(.62) Appearance 27 (13) 21 (13) 2.24(.96) 0.68(.67) Friends 23 (14) 18 (14) 2.11(1.20) 1.11(.58) a Ranks are in parentheses. b Means with standard deviations in parentheses. c Significantly greater than results reported by Silverman et al. (1995). d p <.001. e p <.01. f Significantly less than results reported by Silverman et al. (1995). g p <.05. h Worries were diverse, each specific worry occurring in under 5 cases. Examples were animals and being in the dark. multivariate analyses of variance (MANOVAs). A significant effect of age group was found (Hotellings F = 1.96, p <.01). Univariate tests indicated that older children tended to report more worries about Performance, Future Events, Appearance, and Little Things. Scheffé s contrasts indicated that the 12- to 16-year-old children reported significantly more worries about Performance, Little Things, and Appearance than children ages 6 to 8 years. MANOVAs revealed no significant effects for either gender, income, or ethnicity on the dependent variables. To provide a context for our results, these data were compared to the findings reported by Silverman et al. (1995). 6 First, Spearman s rank correlation coefficient was computed to compare the ranks of the areas of worry between this study and the findings reported by Silverman et al. Specifically, each area in this sample and the Silverman et al. study was ranked from most to least in terms of the number of worries reported, most to least intense area of worry, and most to least frequent area of worry. Correlations found were r s =.88 for number, r s =.73 for intensity, and r s =.62 for frequency (all p <.05). Second, one-sample t tests (Ott, 1993) were conducted on variables standardized across the two studies (i.e., the total number of worries, number of areas of worries, and the average intensity and frequency of worry for each area). Results indicated that the number of worries and the number of areas of worry in the present sample were significantly lower than those reported by Silverman et al. (1995) [t(118) = 4.05, p <.001 and t(118) = 4.88, p <.001, respectively]. However, the intensity of the children s worries was significantly greater in the clinic sample. Mean scores were higher in all 14 areas, and the results of the t tests (summarized in Table I) indicated that in 9 of the 14 areas the clinic children in this study reported that their worries were significantly more intense than those reported by the nonclinic children in the Silverman et al. (1995) study. In terms of frequency, the pattern was mixed in that one area was reported as less frequent by the clinic children, four were reported as more frequent, and nine were not significantly different. Because there were some age-related differences found in this sample, and because the age range of the children studied in the 6 The statistical procedures (i.e., Spearman s rank correlation coefficient (r s ) and the one-sample t tests) selected for these analyses were chosen to allow for a direct statistical comparison of two different sets of data without actually combining the data from each study. We felt most comfortable with this strategy because, although the methodology used to assess worry was the same and a comparison of the present findings with those of Silverman et al. (1995) provides a context for these data, (i.e., helping to identify differences between pathological and normal worry), the studies were conducted independently.

7 Worry in Youth 69 present investigation included children over 12 years old (in Silverman et al., the age range was 7 to 12 years), the influence of age on the sample comparisons was examined. One-sample t tests excluding those cases over 12 years of age revealed almost identical patterns of findings. The specific worries reported by the clinic children for the top five areas of worry were the health of others and getting sick themselves for the Health area; test grades and being called on in class for School; hurricanes and life threat for Disasters; physical attack for Personal Harm; and school/summer school for Future Events. 7 Worry s Relation to Measures of Anxiety The relation of worry with measures of anxiety and fear was examined next, including an examination of the incremental validity of the worry construct. The range and skew for each of the measures indicated acceptable levels for the planned analyses. Correlations between the number, intensity, and frequency of the worries and the selfreport measures of anxiety and fear are presented in Table II. The correlation between the number and intensity of worries was r =.95, number and frequency was r =.78, and frequency and intensity was r =.72, all p <.01. Both the number and intensity of children s worries were significantly correlated with scores on the selfreport measures of anxiety and fear, including all subscales of the SASC-R/SAS-A and RCMAS. The number and the intensity of children s worries were not correlated with the Lie subscale of the RCMAS. The frequency of children s worries was significantly correlated with scores on most of the self-report measures of anxiety except for the CASI scores, the SAD-General, and the SAD-New subscales of the SASC-R/SAS-A, and the Physiological and Lie subscale scores of the RCMAS (see Table II). To evaluate the incremental validity of the worry construct, hierarchical multiple regression analyses were conducted. Specifically, whether worry indices predicted variance in children s fears beyond that predicted by the measures of anxiety was examined. Results are presented in Table III. FSSC-R scores were used as the criterion with age, gender, and ethnicity entered into the equation in Step 1 as covariates; only age was significant, indicating that as age increased, children reported fewer fears. Next, total scores from the RCMAS, SAS/SASC-R, STAIC-T, and CASI were entered into the equation in Step 2. This resulted in a large and significant increase in the amount of variance accounted for in children s FSSC-R scores. 7 A detailed summary of the specific worries across all 14 areas is available from the authors upon request. Table II. Correlations Between Worry Indices and the Self-Report Measures Measure a Number Intensity Frequency CASI.34 b.35 b.14 STAIC-T.41 b.46 b.25 b SAS-T.36 b.38 b.25 b SAS (FNE).33 b.32 b.28 b SAS (SAD-New).31 b.33 b.15 SAS (SAD-General).29 b.34 b.16 RCMAS-T.43 b.45 b.36 b RCMAS-L RCMAS-P.28 b.31 b.18 RCMAS-W.44 b.46 b.36 b RCMAS-C.43 b.41 b.43 b FSSC-R.47 b.50 b.31 b a CASI = Childhood Anxiety Sensitivity Index; STAIC-T = State- Trait Anxiety Scale for Children Trait version; SAS = Social Anxiety Scale, Child or Adolescent versions, T = Total Score, (FNE) = Fear of Negative Evaluation, (SAD-New) = Social Avoidance and Distress New, (SAD-General) = Social Avoidance and Distress General; RCMAS = Revised Children s Manifest Anxiety Scale, T = Total Anxiety Score, L = Lie Factor Subscale, P = Physiological Factor Subscale, W = Worry Factor Subscale, C = Concentration Factor Subscale; FSSC-R = Revised Fear Survey Schedule for Children. Measures of anxiety and fears were all significantly intercorrelated, r ranging from.36 to.75 (all p <.01). b p <.01. Inspection of variance inflation factors indicated acceptable levels (Stewart, 1987) for each of these variables. Because of the high degree of bivariate correlation among the number, frequency, and intensity of children s worries (see bottom of Table II), each of these variables was entered into separate regressions as Step 3 to reduce the influence of multicollinearity. Each of these indices of worry added into the equation in Step 3 resulted in a significant increase in the amount of variance accounted for in children s FSSC-R scores (Table III). Differences in the Expression of Worry in OAD/GAD Versus Simple Phobia We next compared the worries of the OAD/GAD subsample of children with the worries of the simple phobia subsample. As noted, chi-square analyses and t tests revealed no significant differences between the two diagnostic groups in terms of age, ethnicity, income level, and gender. The two groups also did not differ significantly on any of the anxiety self-report measures. In terms of the content of worry, the five most often reported worries of children in the two groups are presented in Table IV. As the table shows, there were more similarities than differences in the content of worries

8 70 Weems, Silverman, and La Greca Table III. Summary of Incremental Validity Regression Analyses with FSSC-R Dependent Variable a Step R 2 R 2 F b p t p β VIF c Age < Gender Ethnicity STAIC-T < RCMAS-T CASI SAS-T Number of worries Frequency of worries Intensity of worries a CASI = Childhood Anxiety Sensitivity Index; STAIC-T = State-Trait Anxiety Scale for Children Trait version; RCMAS = Revised Children s Manifest Anxiety Scale, T = Total Anxiety Score; FSSC-R = Revised Fear Survey Schedule for Children; SAS = Social Anxiety Scale, Child or Adolescent versions, T = Total Score. b F for all full regression models, p <.01. c VIF = variance inflation factor. Table IV. Summary of Diagnostic Group Analyses, Simple Phobia (n = 46) Versus OAD/GAD (n = 26) Most Often Reported Specific Worries a Rank Simple Phobia group OAD/GAD group 1 Physical Attack (22) Tests/grades (17) 2 Hurricanes (21) Hurricanes (16) 3 Tests/grades (12) Physical Attack (15) 4 Family worries (12) Future school (9) 5 Health of others (11) Peer scapegoating (8) Variable M(SD) M(SD) t Number of worries 4.48(4.27) 6.96(5.72) 2.09 b Intensity of worries 0.15(0.17) 0.28(0.25) 2.48 c Frequency of worries 0.04(0.06) 0.06(0.09) 1.30 d Correlations e r r r-z Number and STAIC-T c 2.42 c Intensity and STAIC-T c 2.53 c Frequency and STAIC-T d Number and CASI b 1.59 f Intensity and CASI b 1.80 b Frequency and CASI d STAIC and CASI.51 g.72 g 1.34 d a Number of children reporting worry in parentheses. b p <.05. c p <.01. d No significant difference. e OAD = overanxious disorder; GAD = generalized anxiety disorder. CASI = Childhood Anxiety Sensitivity Index, STAIC-T = State-Trait Anxiety Scale for Children Trait version. f p <.06. g p <.001. reported. The only main difference was that children with OAD/GAD reported worries about the future (in regards to school) and peer scapegoating; children with simple phobia reported worries about the health of others and about the family. A series of t tests were conducted to examine differences in the average number, intensity, and frequency of worries reported by the children with OAD/GAD and the children with simple phobia. As Table IV shows, although there were no differences between the two groups when it came to the frequency of their worries, there were significant differences in the number and intensity of worries. Table IV also presents the correlations between worry (i.e., number, intensity, and frequency) and two of the self-report measures of anxiety (i.e., STAIC-T and the CASI 8 ) for each group. Fisher s r-z statistic was used to compare the correlations between the two groups. Results indicated that self-reports of anxiety were more significantly related to reports of worry among children with OAD/GAD than among children with simple phobia. Once again the aspects of worry that mattered were number and intensity; there was no significant relation between frequency of worry and anxiety. Correlations between STAIC and CASI scores were significant in both groups, and they were not significantly different from each other (see Table IV). 8 Correlations also were computed for the RCMAS and SASC-R/SAS-A. Because the pattern of results obtained were similar across all the selfreport measures, only the CASI and STAIC-T are reported. The complete set of correlations are available from the authors upon request.

9 Worry in Youth 71 DISCUSSION The results indicated that the main areas of worry reported by children who present to an anxiety disorders clinic were: Health, School, Disasters, and Personal Harm. These areas of worry are remarkably similar to those reported in studies that have used community samples (Henker et al., 1995; Muris et al., 1998; Silverman et al., 1995). The areas of worry that were rated as most intense and most frequent in the clinic sample of children also were similar to the ratings of the community sample in Silverman et al. (1995). Given that worry plays such a prominent role in many anxiety disorders, the findings of this study suggest that, at least when it comes to the content of worries, there does not seem to be anything particularly unusual or distinctive about the worry of children who present to an anxiety disorders specialty clinic. In fact, very much like children in community samples, the clinic children appear to be cognizant of contemporary societal concerns such as illness, education, and crime. Also similar to previous research findings were the relations concerning the indices of worry and the anxiety measures (Muris et al., 1998; Perrin & Last, 1997; Silverman et al., 1995). That is, both the number and intensity and, to a lesser extent, frequency of worry were found to be significantly, though moderately, related to self-reports of anxiety. These findings thus provide additional support for the notion that worry and anxiety are related constructs (Barlow, 1988). Given this overlap, however, questions can be raised about whether worry and anxiety are distinct constructs. The results of this study provide initial answers by showing that worry predicted additional variance in children s fears beyond that predicted by measures of anxiety. Demonstrating the incremental validity of worry adds to the research literature. It suggests that the constructs of anxiety and worry should not be used interchangeably and that efforts should be made in future research to delineate the similarities as well as the differences between them, on both theoretical and empirical levels. Another important way that this study adds to the research literature is by identifying what it is about worry or the aspects of worry (i.e., number, frequency, intensity) that is associated with clinical dysfunction. This was investigated in the present study in two ways. The first way was by using the Silverman et al. findings as a context for putting the present findings from the clinic sample in perspective. Although the results suggest that the content of worries of clinic-referred children was similar to that of community samples, intensity of worry differentiated clinic children s worries from those of nonclinic children. Perrin and Last (1997) similarly found that clinicreferred children who met diagnostic criteria for anxiety disorders had significantly more intense worries than children who did not meet criteria, but there was no difference between the groups in terms of the total number of worries. The second way was by comparing aspects of worry within the anxiety-disordered clinic sample, namely, between the children with OAD/GAD and children with simple phobia. The results of this comparison also showed that, once again, intensity of worry differentiated the children with OAD/GAD from the children with simple phobia. That is, children with OAD/GAD rated their worries as more intense than did the children with simple phobia. The worry of children with OAD/GAD also was more related to their self-reported anxiety than the worry of children with simple phobia. Although the number of worries also differed between the children with OAD/GAD and the children with simple phobia, number appears to be more important within a clinic sample than between a clinic sample and a nonclinic sample. That is, only intensity, not number, was found to be significantly different in the previous community sample (Silverman et al., 1995) and the present clinic sample. In fact, children referred for anxiety problems reported an even fewer number of worries than the community children. The importance of intensity of worry relative to number is also highlighted by Perrin and Last s (1997) findings that intense worries were important in differentiating children with anxiety disorders from children without anxiety disorders whereas the number of worries was not. This too suggests that intensity may be the critical aspect of worry that renders it a problem or that leads to a clinic referral. That is, if a child has worries that are strong or intense, it is this intensity that is likely to render it difficult to control (a clinical feature of GAD), impairing, salient to external observers (e.g., parents, teachers), and thus will lead to a clinic referral. Although some might view the finding about the importance of intensity as simply validating the children s diagnoses of GAD/OAD in this study, it is important to recall that it is neither explicitly stated in the DSM nor empirically documented in the research literature what specific aspects of worry render it problematic. Hence, documentation of the potential importance of intensity increases our current knowledge about worry and the possible parameters of the pathology of worry. The study s findings should be considered in light of the following limitations: First, because multiple selfreport measures were employed, there is an issue of shared source variance. A related limitation was the reliance on a single informant. Although children s internalizing symptoms and problems have been found to be more reliably

10 72 Weems, Silverman, and La Greca reported by children themselves rather than by other reporters (e.g., Silverman & Eisen, 1992), future research may benefit from utilizing multiple informants. In addition, the present study examined the linkages between worry and anxiety in a clinical sample of children with anxiety disorders. The ability to generalize these findings to other clinical samples (e.g., clinically depressed children and children with externalizing disorders) awaits further study. A note of caution is also warranted regarding the comparison of the clinical sample with the nonclinical sample. That is, although the same interview was used with both samples to assess worry, the data were collected at different times and under different conditions. Finally, the study does not inform us regarding whether worry is prospectively predictive or just concurrently associated with anxiety and its disorders. Longitudinal research is needed to examine worry s relation to the development of anxiety disorders such as GAD. ACKNOWLEDGMENTS This research was supported in part by National Institute of Mental Health grant #54690 awarded to Wendy K. Silverman. The authors also thank the two undergraduate research assistants, Amanda Cutler and Jessica Rudolf, for their help in the coding of the interview data. REFERENCES Albano, A. M., & Silverman, W. K. (1996). Anxiety Disorders Interview Schedule for DSM-IV Child Version: Clinician manual. San Antonio, TX: Psychological Corporation. American Psychiatric Association (1987). Diagnostic and statistical manual of mental disorders (3rd ed., rev.). Washington, DC: Author. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author. Barlow, D. H. (1988). Anxiety and its disorders: The nature and treatment of anxiety and panic. New York: Guilford Press. Borkovec, T. 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