ویژگی های روان سنجی از اقدامات ناتوانی در میان بیماران مبتلا به اختلال اضطراب اجتماعی

Background: Although recognition of the importance of disability as a construct has increased in recent years, there has been little examination of the reliability and validity of disability measures. Methods: This study examined three disability measures, the Liebowitz Self-Rated Disability Scale (LSRDS), the clinician-rated Disability Profile (DP), and the Sheehan Disability Scale (SDS) among patients with a primary diagnosis of social anxiety disorder. Results: The disability measures correlated strongly with each other, as well as with measures of social anxiety, depressive symptoms, and patients’ subjectively-evaluated quality of life. The LSRDS and DP were more internally consistent than the SDS Total Score. All measures discriminated between patients with generalized and non-generalized social anxiety disorder. However, the LSRDS and DP also showed greater sensitivity to ecological indicators of distress than the SDS. Social anxiety symptoms accounted for significant variance in disability, above and beyond that accounted for by depressive symptoms. Conclusions: Overall, the LSRDS, DP, and SDS appear to be valid tools in the study of disability in social anxiety disorder, although the LSRDS and the DP appear to be somewhat more sensitive to the experiences of socially anxious patients.

As a construct, disability bridges the gap between the deeply personal impact a disorder has on an individual and its effect on his or her ability to fulfill roles as student, worker, spouse, or parent. Disability is certainly related to the presence and severity of symptoms, and the level of disability changes in relation to symptom remission (Olfson et al., 1997). However, disability may also vary among individuals with the same type and intensity of symptoms (Schneier et al., 1994). Rather than emphasizing the personal experience of various symptoms, disability assessment focuses on how a disorder interferes with the individual’s ability to act in the world. Disability is one of the critical diagnostic criteria for most psychiatric disorders (American Psychiatric Association, 1994), and it is an important determinant of a patient’s need for service (Goering, Lin, Campbell, Boyle, & Offord, 1996). Disability measures also provide an important index of the effectiveness of treatment (Goering et al., 1996 and Schneier et al., 1994). Surprisingly, although disability is so important to our understanding of the impact of a disorder and our success in treating it, the measures used to examine disability have rarely been compared and their psychometric properties have rarely been investigated. Social anxiety disorder provides a good example of the need to assess disability in addition to symptom severity. Symptomatically, individuals with social anxiety disorder experience fear in one or more social situations. With regard to disability arising from such symptoms, impairment in the domain of social relationships would be expected to be common. Indeed, Turner, Beidel, Dancu, and Keys (1986) found that 69% of individuals with social anxiety disorder reported impairment in general social relationships, and half of the unmarried individuals in the study reported impairment in their relationships with persons of the opposite sex. In an epidemiological sample, Wittchen, Fuetsch, Sonntag, Muller, and Liebowitz (1999) found that significantly more individuals with social anxiety disorder were never married or were divorced than those without the disorder. A study of psychiatric disorders and relationships found that individuals with social anxiety disorder had fewer friends than persons without mental disorder and reported that they had trouble getting along with the friends they had (Whisman, Sheldon, & Goering, 2000). However, when measuring disability associated with social anxiety disorder, the focus must go beyond disrupted social relationships. Symptoms of social anxiety disorder may have a direct negative impact on occupational functioning, such as when a person fails to obtain employment for fear of job interviews, when the interpersonal demands of a job lead to impaired performance, or when jobs are chosen for the degree to which they minimize feared social contact rather than the extent to which they match the person’s interests and skills. At least a third of afflicted individuals find that coping with social anxiety disorder significantly reduces their productivity (Ballenger et al., 1998). An examination of social anxiety disorder in a primary medical care setting found individuals with social anxiety disorder reported missing an average of 3 days of work and having an average of 6 days of reduced productivity in the last month because of their emotional problems (Stein, McQuaid, Laffaye, & Cahill, 1999). Comparatively, mentally healthy individuals reported less than 1 day of lost work and reduced productivity combined. Unemployment, underemployment (working at a level below the individual’s abilities), and financial dependency are all characteristic of individuals with social anxiety disorder (Mannuzza et al., 1995; Weiller, Bisserbe, Boyer, Lepine, & Lecrubier, 1996; Wittchen et al., 1999). Social anxiety disorder may also be a risk factor for other negative outcomes. It appears to be a risk factor for other disorders, such as major depression and alcoholism (Mannuzza et al., 1995 and Olfson et al., 1997). Furthermore, individuals with social anxiety disorder are likely to consider their health to be poor (Weiller et al., 1996). Given this myriad of direct and indirect consequences of social anxiety, it is not surprising that individuals with social anxiety disorder are at greater risk for suicidal ideation than persons without the diagnosis (Schneier, Johnson, Hornig, Liebowitz, & Weissman, 1992). Some researchers have raised the question of how much of the interference associated with social anxiety disorder might be attributable to its association with other disorders, especially depression (Stein et al., 1999 and Weiller et al., 1996). Stein and Kean (2000) examined these relationships in an epidemiological sample and found that associations between social anxiety disorder and various domains of disability and quality of life (e.g., family life, friends, and income) remained significant when controlling for depression. However, this question has not been addressed in a sample of patients with social anxiety disorder before the current study. Perhaps the biggest challenge to the assessment of disability is the lack of clear understanding of the advantages and disadvantages of measures in current use. Two self-report measures, the Sheehan Disability Scale (SDS; Sheehan, 1983) and the Liebowitz Self-Rated Disability Scale (LSRDS; Schneier et al., 1994), and one clinician-rated measure, the Disability Profile (DP; Schneier et al., 1994), have been used to measure disability among individuals with social anxiety disorder. The SDS was one of the first and is the most frequently used disability measure. It has demonstrated sensitivity to impairment and changes as a result of treatment across a wide range of disorders, including depression, bipolar disorder, specific phobias, agoraphobia, generalized anxiety disorder, substance abuse, eating disorders, and antisocial personality disorder, as well as social anxiety disorder (Olfson et al., 1997). Unfortunately, the SDS has only four items (of which only three are typically used). It is limited in terms of the specificity of information that it elicits and the breadth of the content domain that it samples. Furthermore, the SDS asks only about current levels of impairment, providing no indication of whether the person has done better or worse in the past. The LSRDS separately examines current and lifetime impairment in multiple domains as a result of the person’s “emotional problem.” Individual items may be examined to assess interference in particular domains as part of treatment planning (although the treatment validity of this approach has never been evaluated). In at least two different studies, the LSRDS scales have shown moderate to strong relationships with measures of symptoms and role functioning among individuals with social anxiety disorder (Schneier et al., 1994 and Wittchen et al., 1999). The DP is a clinician-rated instrument that examines both current and lifetime impairment in most of the same domains assessed by the LSRDS. Again, the individual is asked to specify disability resulting from a particular disorder. The DP has been used less frequently and little information is available on its reliability and validity beyond the data presented in the original article, in which it was shown to have good internal consistency and moderate to strong relationships with measures of symptomatology and disability in individuals with social anxiety disorder (Schneier et al., 1994). Neither the LSRDS nor the DP has been used extensively with other disorders, although nothing in their content precludes this possibility (Mendlowicz & Stein, 2000). This study explores several aspects of the use of the SDS, LSRDS, and DP among persons presenting for treatment for social anxiety disorder. First, it investigates the internal consistency and validity of these measures, particularly in the way these disability measures relate to each other and to symptoms of social anxiety, depression, and quality of life. Second, it examines whether the disability measures are sensitive to demographic differences in the patient sample. Third, the study looks at the unique contribution of symptoms of social anxiety disorder to disability scores, to see if social anxiety disorder is disabling in its own right, or if instead, its disabling effects can be accounted for by its overlap with depression.