Instruments for the assessment of social anxiety disorder: Validation studies

Abstract

Great progress has been observed in the literature over the last decade regarding the validation of instruments for the assessment of Social Anxiety Disorder in the Brazilian context. Particularly outstanding in this respect is the production of a group of Brazilian investigators regarding the psychometric study of the following instruments: Liebowitz Social Anxiety Scale, Social Phobia Inventory, Brief Social Phobia Scale, Disability Profile, Liebowitz Self-Rated Disability Scale, Social Phobia Safety Behaviors Scale and Self-Statements During Public Speaking Scale, which have proved to be appropriate and valid for use in the adult Brazilian population, representing resources for the assessment of social anxiety in clinical and experimental situations.

Key Words: Social anxiety; Social phobia, Instruments; Validation; Scale

TEXT

Social anxiety disorder (SAD) is characterized by a marked and persistent fear of situations of social performance and interaction in which an individual may feel humiliated, embarrassed or negatively evaluated[1]. It is considered to be the third most prevalent psychiatric disorder, with a chronic course associated with the development of comorbidities[2,3]. Although it is treatable, this disorder is underdiagnosed, so that about 2/3 of affected individuals do not receive appropriate treatment, a fact that favors the onset of major clinical and psychosocial impairment[4,5].

Assessment instruments can be used as strategies for the large-scale screening of SAD and the characterization of the associated symptoms and damage. A literature review of the instrument for SAD evaluation[6] pointed out about 23 available instruments with varying objectives, forms of application and extension. The study also indicated that some of them, such as the Fear of Negative Evaluation and the Social Avoidance and Distress Scale, were already available before the official recognition of SAD as a psychiatric disorder[7], which occurred in 1994[1]. Most of the remaining instruments were proposed during the 1990s and some more recently, up to the mid 2000s. Conversely, in Brazil, up to the mid 2000s[6,8], there was no original instrument available in the national literature or validated for this sociocultural context.

On this basis, our research group conducted an ample thematic study involving different aspects of SAD, such as epidemiological aspects, neuroimaging diagnosis, therapeutic approaches and studies of the validation of a set of instruments applicable to adults. The objective was to validate instruments previously referenced in the literature, with their use recognized for the assessment of adults and for application in the clinical-experimental context. Among them, we may first cite the Liebowitz Social Anxiety Scale (LSAS)[9], the Social Phobia Inventory (SPIN)[10] and the Brief Social Phobia Scale (BSPS)[11], which were validated in samples of the general population and in a clinical SAD sample involving cases, non-cases and subclinical subjects. Information regarding these instruments is briefly described below.

The LSAS is the self-rating scale most extensively studied all over the world regarding its psychometric qualities, is most frequently used in clinical assays and has been validated for five languages, in addition to the English original[8]. The parameters of the validated Brazilian version agree with the international ones in terms of validity and reliability. The validated Brazilian scale can also discriminate between subjects diagnosed as SAD cases and those diagnosed as subclinical cases. Also, in the latter group, whose main characteristic is the absence of significant damages associated with the symptoms, the intensity of the frequency of fear and avoidance was also lower than that observed in the case group.

The SPIN is a self-rating instrument which, like the LSAS, intends to assess fear and avoidance symptoms, differing from the LSAS by evaluating physiological symptoms, such as palpitation, blushing, tremor and transpiration, also associated with the disorder, by means of four specific items. The SPIN has been validated for use in different languages[6]. The Portuguese version showed adequate psychometric indicators regarding internal consistency, concurrent validity and discriminant validity[12,13]. The reduced version of the SPIN, the Mini-SPIN (MS)[14], consisting of three items of the original scale, is an instrument of even shorter and more rapid application, with high discriminant power. In contrast to studies with other versions of the MS, the cut-off note of seven seems to be more adequate for use in Brazil, keeping a balance between sensitivity and specificity[15].

The BSPS is a hetero-applied instrument which, by involving evaluation by a clinician, is useful when we consider that individuals often have difficulty in recognizing symptoms and identifying them as part of a disorder. For the application of this scale, we proposed a question guide for the systematization and standardization of the instrument, which led to an increase of about 25% in inter-rater diagnostic agreement[16].

Our group also validated scales that assess the psychosocial damages associated with SAD, which represent important diagnostic criteria of the disorder, especially in order to differentiate clinical from subclinical signs and symptoms. Two scales, a hetero-assessment one (The Disability Profile)[9] and a self-rating one (Liebowitz Self-Rated Disability Scale)[17], were checked and the findings agreed with those of the original study. Comparison of the two scales revealed that the self-rating scale showed subtly superior parameters[18].

Studies with instruments that assess the specificities of SAD are also important, such as safety behaviors and fear of public speaking. The Social Phobia Safety Behaviors Scale[19] is a self-rating scale designed to evaluate safety behaviors that social phobics use in the feared situations. Safety behaviors have been defined as a wide range of behaviors that social phobics carry out when in social situations and through which they try to reduce the risk of negative evaluation, trying to prevent feared outcomes from occurring. The Brazilian study of the instrument pointed out a test-retest reliability of 0.1 to 0.90 (2 wk) and factorial analysis revealed the presence of a single factor explaining 54.1% of data variance[20].

Regarding the instrument that assesses the specific aspects of public speaking, we validated the Self-Statements During Public Speaking Scale[21], whose factorial analysis pointed out, as observed in the initial psychometric study, the presence of two factors: positive self-assessment and negative self-assessment, explaining 52% of data variance. An adapted version of this instrument[22] has been used in experimental studies that employ models of anxiety (Simulated Public Speaking Test)[23]. The subscale of negative self-assessment was the one that proved to be most sensitive in discriminating cases from non-cases and from subclinical subjects[24], supporting the hypothesis of the cognitive etiology of SAD associated with a negative self-perception since, in these experiments, SAD cases tend to obtain a higher score on this subscale.

We should also point out the importance of using specific scales for SAD evaluation, especially regarding screening. Even considering that the diagnosis of this disorder is clinical and based on the indication of a specialist, the specific scale of SAD signs and symptoms has a greater discriminative power compared to general anxiety scales, such as the Beck Anxiety Inventory (BAI)[25]. An example of this can be seen in the study conducted by us which detected a 20% higher discriminative power for SAD screening with the use of the SPIN compared to the BAI, which favored false-positive indices[26].

In addition to these studies, there are others conducted in parallel by other local research groups which have validated other scales for SAD evaluation, such as the Social Phobia and Anxiety Inventory[27,28], the Social Avoidance and Distress Scale[29] and the Social Interaction and Self-Statement[30], also detecting favorable indicators that recommend their use, expanding even more the instrumental arsenal for SAD evaluation within both a clinical and research context.

We conclude that the studies conducted by our group and others have made available a wide variety of instruments that can be used to assess adults within the SAD context, filling an important gap in the literature.