Anxiety and Depression: Evidence for the Differentiation of Commonly Cooccurring Constructs

Anxiety and depression frequently cooccur diagnostically. This observation has led researchers to investigate whether anxiety and depression can be meaningfully distinguished as unique theoretical constructs or whether they are better conceptualized as features of a general psychological distress. In the present study, we attempted to differentiate self-reported state and trait anxiety from depression in a university sample (N = 593) using the Beck Depression Inventory (BDI) and the Endler Multidimensional Anxiety Scales (EMAS). In addition, we examined the relationship among self-reported anxiety, depression, and neuroticism to determine the extent to which the Anxiety and Depression facet scales of the NEO Personality Inventory—Revised represent distinct and mutually exclusive measures of anxiety and depression. Principal-components analyses and a series of multiple regression models were used to conduct this investigation. Results indicate that both state and trait anxiety and depression can be reliably differentiated with the BDI and the EMAS. Results also suggest that invoking a single general distress factor to explain the strong interrelationships between anxiety and depression in nonclinical samples is premature.     

Self-reports of depression and state-trait anxiety: evidence for differential assessment.

Several researchers have found anxiety and depression to be indistinguishable in nonclinical samples and have suggested that both constructs may be components of a general psychological distress process. Another possibility is that overlap is due to the psychometric limitations of scales used. A series of exploratory factor analyses were conducted in a nonclinical sample (N = 605) using the Beck Depression Inventory (BDI; Beck, 1978), the State-Trait Anxiety Inventory (STAI; Spielberger, 1983), and the Endler Multidimensional Anxiety Scales (EMAS; Endler, Edwards, & Vitelli, 1991). Both state and trait anxiety and depression could be differentiated with the BDI and the EMAS but not with the STAI. Some theoretical models of negative affectivity or general psychopathology may be premature.     

The Prospective and Retrospective Memory Questionnaire (PRMQ): Normative data and latent structure in a large non-clinical sample

The Prospective and Retrospective Memory Questionnaire (PRMQ; Smith, Della Sala, Logie, & Maylor, 2000) was developed to provide a self-report measure of prospective and retrospective memory slips in everyday life. It consists of sixteen items, eight asking about prospective memory failures, and eight concerning retrospective failures. The PRMQ was administered to a sample of the general adult population (N = 551) ranging in age between 17 and 94. Ten competing models of the latent structure of the PRMQ were derived from theoretical and empirical sources and were tested using confirmatory factor analysis. The model with the best fit had a tripartite structure and consisted of a general memory factor (all items loaded on this factor) plus orthogonal specific factors of prospective and retrospective memory. The reliabilities (internal consistency) of the Total scale and the Prospective and Retrospective scales were acceptable: Cronbach's alpha was 0.89, 0.84, and 0.80, respectively. Age and gender did not influence PRMQ scores, thereby simplifying the presentation and interpretation of normative data. To ease interpretation of scores on the PRMQ, tables are presented for conversion of raw scores on the Total scale and Prospective and Retrospective scales to T scores (confidence limits on scores are also provided). In addition, tables are provided to allow users to assess the reliability and abnormality of differences between an individual's scores on the Prospective and Retrospective scales.     

The Structure of Anxiety and Depression in a Normative Sample of Younger and Older Australian Adolescents

It has been reported that depression and anxiety have overlapping symptoms and are conceptually interrelated. One of the most prominent theoretical developments that explain this association is Clark and Watson’s tripartite model (Journal of Abnormal Psychology, 100:316–336, 1991) that posits these two disorders and negative emotions share a latent component of negative affect (NA). The current study had two aims, (a) to compare a tripartite factor structure against competing models by Confirmatory Factor Analysis (CFA) of the Depression Anxiety and Stress Scales (DASS-21) (Lovibond and Lovibond 1995), and (b) explore the psychometric properties of the DASS-21. The DASS-21 was completed by a representative sample of 4039 young Australians, aged 12–18 years, as part of the South Australian Youth Mental Health Survey (SAYMHS), South Australia, Australia. The best fitting model for the data consisted of anhedonic depression, physiological hyperarousal, and general NA. The psychometric properties of the DASS-21 were excellent with a stable and interpretable factor structure and good internal consistency. The results of the current study suggest that the theoretical tripartite structure of depression and anxiety is robust and applicable among Australian youth. The diagnostic, clinical and theoretical implications of these findings are discussed.     

Effectiveness of the Hamilton Anxiety Rating Scale with Older Generalized Anxiety Disorder Patients

To expand the collection of instruments available for assessment of anxiety in the elderly, this report examined the original and revised Hamilton anxiety scales in a sample of 50 older adults diagnosed with Generalized Anxiety Disorder (GAD) and 93 normal community participants (ages 55–82). Although the revised anxiety scale had better discriminant validity (lower correlation with the revised Hamilton depression scale) than the original anxiety and depression scales, a considerable amount of shared variance still existed (41% shared variance, GAD sample alone; 17% control sample alone; 74% shared variance, both samples combined). Near-perfect group classification was possible using 7 items from the original anxiety scale and 10 items from the revised anxiety scale. Results are discussed in light of their implications for use of the Hamilton anxiety rating scale with older anxiety-disordered patients.     

Depression Anxiety Stress Scales-21: Factor Structure and Test-Retest Invariance,and Temporal Stability and Uniqueness of Latent Factors in Older Adults

This study examined the factor structure and test-retest invariance, and temporal stability and uniqueness of the latent factors (depression, anxiety, and stress) of the Depression Anxiety Stress Scales-21 (DASS-21; Lovibond & Lovibond, 1995) in group a of 269 older adults (age ranging from 60 to 85 years) from the general community. Participants completed the DASS-21 twice, 3 months apart. Confirmatory factor analysis (CFA) of their ratings at Time 1 indicated support for the original 3-factor oblique model (factors for depression, anxiety, and stress). Additional analyses showed support for test-retest invariance for both the measurement (configural, metric and thresholds) and structural (variances and covariances) components of this model. Results also indicated temporal stability and uniqueness of the latent factors. The practical, theoretical, research and clinical implications of the findings are discussed.     

The Prospective and Retrospective Memory Questionnaire (PRMQ): Normative data and latent structure in a large non-clinical sample

The Prospective and Retrospective Memory Questionnaire (PRMQ; Smith, Della Sala, Logie, & Maylor, 2000) was developed to provide a self-report measure of prospective and retrospective memory slips in everyday life. It consists of sixteen items, eight asking about prospective memory failures, and eight concerning retrospective failures. The PRMQ was administered to a sample of the general adult population (N = 551) ranging in age between 17 and 94. Ten competing models of the latent structure of the PRMQ were derived from theoretical and empirical sources and were tested using confirmatory factor analysis. The model with the best fit had a tripartite structure and consisted of a general memory factor (all items loaded on this factor) plus orthogonal specific factors of prospective and retrospective memory. The reliabilities (internal consistency) of the Total scale and the Prospective and Retrospective scales were acceptable: Cronbach's alpha was 0.89, 0.84, and 0.80, respectively. Age and gender did not influence PRMQ scores, thereby simplifying the presentation and interpretation of normative data. To ease interpretation of scores on the PRMQ, tables are presented for conversion of raw scores on the Total scale and Prospective and Retrospective scales to T scores (confidence limits on scores are also provided). In addition, tables are provided to allow users to assess the reliability and abnormality of differences between an individual's scores on the Prospective and Retrospective scales.     

Depression Anxiety Stress Scales: Factor structure and differential item functioning across women and men

This study examined the factor structure, and differential item functioning of the Depression Anxiety Stress Scales (DASS; Lovibond & Lovibond, 1995) across sex. The DASS was completed by 201 women and 165 men from the general community. Confirmatory factor analysis (CFA) indicated support for the original 3-factor oblique model (factors for depression, anxiety and stress). There was however more support for a bifactor model, with four orthogonal factors: a general factor on which all the depression, anxiety and stress items load, and specific independent factors for depression, anxiety and stress items. None of the DASS items showed DIF. The practical, theoretical, research and clinical implications of the findings are discussed.     

Generalized anxiety and panic disorders: Response to Cox, Cohen, Direnfeld, and Swinson (1996)

Contrary to the contention of Cox, Cohen, Direnfeld and Swinson (1996, Behaviour Research and Therapy, 34, 949–954) that the Beck Anxiety Inventory (BAI; Beck & Steer, 1993, Manual for the Beck Anxiety Inventory) measures primarily symptoms associated with panic attacks rather than anxiety in general, we propose that the higher level of anxiety found in patients with panic disorders not only is not an artifact of the BAI's symptom content, but patients with panic disorders truly have more anxiety than patients with other types of anxiety disorders. Furthermore, the BAI contains symptoms present in other anxiety disorders, besides panic disorder, and specifically includes 11 symptoms of generalized anxiety disorder (GAD). The BAI and revised Hamilton Anxiety Rating Scale (HARS-R; Riskind, Beck, Brown & Steer, 1987, Journal of Nervous and Mental Disease, 175, 474–479) scores of 274 (69%) outpatients with panic disorders and 123 (31%) outpatients with GAD were found to differentiate these two diagnostic groups equally and significantly. The panic disorder outpatients had higher scores on both the BAI and the HARS-R than did the GAD patients. Thus, Cox et al.'s (1996) speculation about the BAI's yielding spuriously high levels of anxiety in patients with panic disorders revives an important issue relevant to the relation of panic disorder to GAD.     

Investigating the Factor Structure of the Kessler Psychological Distress Scale in Community and Clinical Samples of the Australian Population

The Kessler 10 Psychological Distress Scale (K10) is a brief dimensional scale designed to measure and monitor trends of psychological distress. Recently the scale has been utilised by general practitioners and clinicians to screen for common mental disorders and measure treatment outcomes. Despite the K10 demonstrating a sound one dimensional structure in the general population, the scale??s structure has yet to be comprehensively tested in clinical samples. The current study aimed to use confirmatory factor analysis to test three theoretical structure models of the K10 and one model for the K6 (a six item variant) in a sample from a tertiary referral clinic for mood and anxiety disorders and compare those results with a population sample from the Australian National Survey of Mental Health and Wellbeing. The results demonstrated that a two factor model with correlated latent factors representing depression and anxiety fit the clinical sample the best whilst a one factor model with correlated errors between several items fit the population sample the best. The results are discussed further in relation to scoring and interpreting the Kessler scales.     

The Yale-Brown Obsessive-Compulsive Scale: Confirmatory Factor Analytic Findings

The psychometric properties of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) have recently been heavily examined. Specifically, a number of researchers have been interested in determining the factor structure of this scale to find whether it best forms a one, two, or three factor model. The present study continued this examination by considering different scaling models using confirmatory factor analysis with a sample of individuals diagnosed with Obsessive-Compulsive Disorder (OCD). One hundred and forty-six individuals diagnosed with OCD participated and were administered the Y-BOCS and scales measuring depression (Hamilton Depression Rating Scale) and anxiety (Hamilton Anxiety Rating Scale). It was found that the Y-BOCS forms two different two-factor models. One model consisted of an obsessions and compulsions factor; the other composed of disturbance and symptom severity factors. It was likewise found that depression and anxiety were related to both factors in one model (disturbance and symptom severity). The finding that depression was related to obsessions and anxiety to compulsions was found, as in a previous factor analysis of the Y-BOCS. These findings suggest that OCD may be best characterized as a multidimensional syndrome that may not be adequately examined by a single unitary factor as described in the Y-BOCS.     

Religiosity,happiness, health,and psychopathology in a probability sample of Muslim adolescents

The aim of the present study was to explore the religiosity associations with the self-rating scales of happiness, mental health, physical health, anxiety, and depression. A sample (N?=?6,339) of Muslim Kuwaiti adolescents was recruited. Their ages ranged from 15 to 18. They responded to four self-rating scales to assess religiosity, happiness, mental health, and physical health, as well as the Kuwait University Anxiety Scale, and the Center for Epidemiologic Studies-Depression Scale. Boys had higher mean scores on happiness, mental health, and physical health than did girls, whereas girls had higher mean scores on religiosity, anxiety, and depression. All the correlations were significant in both sexes. They were positive between each of the self-rating scales of religiosity, happiness, mental health, and physical health, and negative between these four rating scales and both anxiety and depression. A high-loaded and bipolar factor was disclosed and labelled “Religiosity and well-being vs. psychopathology.” In the stepwise regression, the main predictor of religiosity was happiness in both sexes.     

The validity of personal disturbance scale (DSSI/sAD) in people with diabetes mellitus,using longitudinal data

Despite being used since 1976, Delusions-Symptoms-States-Inventory/states of Anxiety and Depression (DSSI/sAD) has not yet been validated for use among people with diabetes. The aim of this study was to examine the validity of the personal disturbance scale (DSSI/sAD) among women with diabetes using Mater-University of Queensland Study of Pregnancy (MUSP) cohort data. The DSSI subscales were compared against DSM-IV disorders, the Mental Component Score of the Short Form 36 (SF-36 MCS), and Center for Epidemiologic Studies Depression Scale (CES-D). Factor analyses, odds ratios, receiver operating characteristic (ROC) analyses and diagnostic efficiency tests were used to report findings. Exploratory factor analysis and fit indices confirmed the hypothesized two-factor model of DSSI/sAD. We found significant variations in the DSSI/sAD domain scores that could be explained by CES-D (DSSI-Anxiety: 55%, DSSI-Depression: 46%) and SF-36 MCS (DSSI-Anxiety: 66%, DSSI-Depression: 56%). The DSSI subscales predicted DSM-IV diagnosed depression and anxiety disorders. The ROC analyses show that although the DSSI symptoms and DSM-IV disorders were measured concurrently the estimates of concordance remained only moderate. The findings demonstrate that the DSSI/sAD items have similar relationships to one another in both the diabetes and non-diabetes data sets which therefore suggest that they have similar interpretations.     

The Hospital Anxiety and Depression Scale: a pilot study to examine its latent structure and the link between psychological state and symptom severity in transient ischaemic attack patients

Transient ischaemic attack (TIA) is often associated with anxiety and depression, which may precipitate secondary stroke and interfere with treatment. The Hospital Anxiety and Depression Scale (HADS) is widely used to assess these states and to inform the management of any associated psychological problems, but there is considerable debate about what it actually measures. The HADS scores from a range of different clinical groups have been reviewed in order to assess its psychometric properties, but so far, no research has examined either its latent structure when used with TIA patients, or the association between symptom severity and the test’s validity. The aims of this study, therefore, were to investigate: (a) the underlying structure of the HADS when used with TIA patients; and (b) the impact of symptom severity on the validity of the HADS. The HADS and a functional capacity measure were administered by post to a sample of 542 confirmed TIA patients. Exploratory factor analysis was conducted on the HADS scores to establish its underlying structure for this clinical group, and then, sub-sample correlations were undertaken between the anxiety/depression scores for different levels of functional capacity. Two factors emerged, with 13 of the 14 HADS items loading significantly on both, suggesting there is a common affective state underlying the standard anxiety and depression scales. Further data-exploration indicated that convergence between these affective states increased as functional capacity deteriorated. The results suggest firstly that the HADS measures general subjective distress when used with TIA patients, and secondly that the higher reported symptom severity in this clinical group may be associated with reduced affective differentiation. As the ability to retain clear affective discrimination is associated with health and well-being, this could provide a focus for post-TIA rehabilitation.     

Factor solutions of the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) in a Swedish population

Culturally validated rating scales for social anxiety disorder (SAD) are of significant importance when screening for the disorder, as well as for evaluating treatment efficacy. This study examined construct validity and additional psychometric properties of two commonly used scales, the Social Phobia Scale and the Social Interaction Anxiety Scale, in a clinical SAD population (n?=?180) and in a normal population (n?=?614) in Sweden. Confirmatory factor analyses of previously reported factor solutions were tested but did not reveal acceptable fit. Exploratory factor analyses (EFA) of the joint structure of the scales in the total population yielded a two-factor model (performance anxiety and social interaction anxiety), whereas EFA in the clinical sample revealed a three-factor solution, a social interaction anxiety factor and two performance anxiety factors. The SPS and SIAS showed good to excellent internal consistency, and discriminated well between patients with SAD and a normal population sample. Both scales showed good convergent validity with an established measure of SAD, whereas the discriminant validity of symptoms of social anxiety and depression could not be confirmed. The optimal cut-off score for SPS and SIAS were 18 and 22 points, respectively. It is concluded that the factor structure and the additional psychometric properties of SPS and SIAS support the use of the scales for assessment in a Swedish population.     

Is the state-trait anxiety inventory multidimensional?

The factor structure of the State-Trait Anxiety Inventory (STAI) was investigated to determine whether the STAI State and Trait Anxiety scales were multidimensional. The STAI (Form Y) was administered to a heterogeneous sample of Air Force recruits (N = 1728); the scores for all 40 STAI items were factor-analyzed together, using the principal axis method and varimax rotation. Two- and four-factor solutions were found to be equally good in simple structure and psychological meaningfulness. Clearly defined state and trait anxiety factors were found in the more parsimonious two-factor solution. In the four-factor solution, the factors were: State Anxiety-Present, State Anxiety-Absent, Trait Anxiety-Present and Trait Anxiety-Absent. Using Cattell's (1966) confactor method, these factors were found to be congruent with similar factors previously identified for high school students by Spielberger et al. (1980). The anxiety-present and anxiety-absent factors were interpreted as reflecting either ‘item method’ variance or ‘item-intensity specificity’. There was no evidence in the present study that the STAI scales were multidimensional in terms of item content.     

State–trait anxiety and existential fear: an empirical analysis

The Fear Checklist consists of 18 items (e.g. intimacy, loss of control, failure) a respondent checks to signify areas that have been or currently are personal sources of concern and/or apprehension. Total scores on the Fear Checklist, along with scores on each of its three subscales (Social, Control, Identity), were correlated with the state (A-State) and trait (A-Trait) anxiety scales of the State–Trait Anxiety Inventory (STAI). Both the A-State and A-Trait scales demonstrated significant association with the total Fear Checklist score (r_stat =0.48, r_trait=0.50) and each of its three subscales in a group of 135 male federal prisoners. Despite substantial overlap between the A-State and A-Trait scales (r=0.76), each achieved significant partial correlations with the total Fear Checklist score when the other scale was controlled (i.e. the A-Trait score was controlled in the state anxiety–fear relationship and the A-State score was controlled in the trait anxiety–fear relationship). These results lend preliminary support to the notion that existential fear, as measured by the Fear Checklist, is sensitive to both dispositionally (A-Trait) and situationally (A-State) based anxiety, although the majority of variance shared by the STAI and Fear Checklist was common to both STAI scales.     

Assessment of anxiety and depression in young children: support for two separate constructs

Validated the interrelatedness of depression and anxiety in young children by testing four latent factor models: dual construct, unrelated; dual construct, correlated; single construct; and second-order or higher order analysis to test that depression and anxiety are primary constructs under the higher order factor of general affective distress. Children (N = 86) were ages 6 to 11, with mothers who were HIV-symptomatic or diagnosed with AIDS. Depression and anxiety measures included the Children's Depression Inventory (Kovacs, 1992), selected items from the Dominic-R (Valla, Bergeron, Berube, Gaudet, & St-Georges, 1994), and the Revised Children's Manifest Anxiety Scale (Reynolds & Richmond, 1985). Structural equation modeling was used to test the models. Model 2 (dual construct, correlated) fit the data better than did Models 1 and 3; results for the higher order model were identical to Model 2, suggesting the higher order model is equivalent to the dual-construct model.     

Three traditional and three new childhood anxiety questionnaires: their reliability and validity in a normal adolescent sample

The current study examined the psychometrics of three traditional [i.e., the trait anxiety version of the State-Trait Anxiety Inventory for Children (STAIC), the Revised Children's Manifest Anxiety Scale (RCMAS), and the Fear Survey Schedule for Children - Revised (FSSC-R)] and three new childhood anxiety scales [the Multidimensional Anxiety Scale for Children (MASC), the Screen for Child Anxiety Related Emotional Disorders (SCARED), and the Spence Children's Anxiety Scale (SCAS)] in a large sample of normal adolescents (N=521). Childhood anxiety scales were generally found to be reliable in terms of internal consistency. Furthermore, evidence was obtained for the convergent and divergent validity of the various anxiety questionnaires. That is, anxiety questionnaire scores were found to be substantially intercorrelated. Particularly strong associations were found between total scores of the STAIC and the RCMAS, total scores of the SCARED and the SCAS, and between subscales that intend to measure specific categories of anxiety symptoms. Childhood anxiety questionnaires were substantially connected to an index of depression, although correlations among anxiety questionnaires were generally higher than those between anxiety scales and a measure of depression.     

Dimensional, categorical, or dimensional-categories: testing the latent structure of anxiety sensitivity among adults using factor-mixture modeling

The present study tested multiple, competing latent structural models of anxiety sensitivity (AS), as measured by the Anxiety Sensitivity Index-3 (ASI-3; Taylor et al., 2007). Data were collected from 3 sites in North America (N = 634). Participants were predominantly university students (M = 21.3 years, SD = 5.4). ASI-3 data were evaluated using an integration of mixture modeling and confirmatory factor analysis—factor mixture modeling (FMM; Muthén, 2008). Results supported a 2-class 3-factor partially invariant model of AS. Specifically, the FMM analyses indicated that AS is a taxonic (two-class) variable, and that each categorical class has a unique multidimensional factor structure. Consistent with the specific point-prediction regarding the hypothesized parameters of the putative latent class variable, FMM indicated that the putatively “high-risk” subgroup of cases or latent form of AS composed approximately 12% of the studied sample whereas the putatively “normative” subgroup of cases or latent form of AS composed 88% of the sample. In addition, the AS Physical and Psychological Concerns subscales, but not the Social Concerns subscale, most strongly discriminated between the two latent classes. Finally, comparison of continuous levels of AS Physical and Psychological Concerns between FMM-derived AS latent classes and independent clinical samples of patients with anxiety disorders provided empirical support for the theorized taxonic-dimensional model of AS and anxiety psychopathology vulnerability. Findings are discussed in regard to the implications of this and related research into the nature of AS and anxiety psychopathology vulnerability.