The present study provides estimates of health-related quality of life across the common DSM-IV anxiety disorders in a nationally representative US adult sample. These findings add to the empirical literature that portrays the burden of anxiety disorders.2–6
Roughly one in ten adult U.S. adults met diagnostic criteria for at least one 12-month DSM-IV anxiety disorder. In relation to the non-anxiety-disordered general population, these adults tend to have lower personal income, increased rates of 12-month physical conditions, and greater numbers of other psychiatric disorders. Adults with anxiety disorders also tend to report poorer social functioning, role functioning, mental health, and overall mental and physical well-being. When considered in the context of standardized norms for the SF-12v2 from the National Survey of Functional Health Status,53
individuals with DSM-IV SAD, GAD, and PD exhibit considerably poorer overall mental well-being, but not physical well-being, than individuals with cancer, diabetes, heart disease, arthritis, hypertension, and a host of other chronic physical conditions. These findings underscore the magnitude of the burden of disease associated with anxiety disorders. Clinical efforts to redress problems of individuals affected by DSM-IV anxiety disorders should include health-related quality of life assessments to detect cases, identify treatment targets, and evaluate treatment effectiveness.
Among the anxiety disorders under study, GAD emerged as the most impairing. During the course of one year, approximately 2% of adults meet GAD criteria. As a group, they were at significantly increased risk of impaired social and role functioning, mental health, and overall physical and mental well-being. Notably, overall mental well-being for individuals with 12-month GAD was almost two standard deviations below that identified for “healthy” individuals (i.e., those with no chronic conditions) in the National Survey of Functional Health Status.53
Even after accounting for several potentially confounding socio-demographic and clinical correlates—correlates that may also represent outcomes of psychiatric disorders—GAD retained significant negative associations with all quality of life indices, with the exception of physical well-being. This observation builds on previous clinical work with relatively small samples that has documented poor quality of life among patients with GAD26,37,42
and brings a renewed sense of urgency to efforts to improve treatment access for this disorder. Contrary to the assertion of individuals with GAD as the “worried well,”58
the present findings suggest individuals with GAD experience occupational and personal dissatisfaction as well as social and economic disadvantage.
Consistent with previous work30,39,41,59–61
SAD was related to impaired social and role functioning, mental health, and overall physical and mental well-being. Because the most impaired cases of SAD frequently present with comorbid avoidant personality disorder,62–63
accounting for potentially confounding DSM-IV Axis II disorders might substantially attenuate associations between SAD and quality of life indicators. In the current study, however, all relationships between SAD and quality of life indicators became non-significant after adjusting for socio-demographic and clinical correlates, and their level of significance did not change after adjusting for psychiatric comorbidity. This suggests that most of the impairment associated with SAD is concentrated in areas related to relationships and work achievement and in community samples is not mediated by the co-occurrence of other psychiatric disorders.
Panic disorder appears to fall between the less impairing SAD and the more impairing GAD. Consistent with previous work conducted on smaller and more selected samples,64–67
12-month PD predicted impaired social and role functioning, mental health, and overall physical and mental well-being. Failure to retain a significant relationship with physical well-being is consistent with the work of Sherbourne and colleagues,67
who found self-reported physical well-being of selected PD outpatients to be closer to that of the general population than that of individuals with chronic physical conditions. In contrast, individuals with PD exhibited considerably poorer overall mental well-being (mean=43.8) than individuals drawn from the National Survey of Functional Health Status with a number of chronic physical conditions—conditions including cancer (47.1), diabetes (47.3), heart disease (48.3), and arthritis (47.1).53
The poor social and role functioning observed may reflect the high rates of behavioral and situational avoidance that are common in PD.68,69
Specific phobia was associated with significant, though considerably less impaired health-related quality of life than the other anxiety disorders. Surprisingly, however, after accounting for socio-demographic and clinical correlates, associations between SP and social functioning, role functioning, mental health, and overall mental well-being actually predicted improved quality of life. The relationship between SP and poor quality of life may actually be better accounted for by co-occurring conditions than by the specific phobia. The current findings suggest a suppression effect,70
in which an apparent positive association between SP on quality of life is suppressed by associations of SP with correlates that have negative associations with quality of life.
Individuals with anxiety disorders, relative to the non-anxiety-disordered population, reported substantially higher prevalence of co-morbid medical conditions. Among the anxiety disorders, medical co-morbidities were particularly high among individuals with GAD and PD. Although the mechanisms and direction of these associations remain unclear and it is not possible to draw causal inferences from cross sectional associations, these anxiety disorders may increase the risk of developing or maintaining some general medical disorders in vulnerable individuals. For example, gastric secretions associated with chronic worry in GAD may promote peptic ulceration.71
Alternatively, some general medical conditions may increase in the risk of specific anxiety disorders.
Prevalence rates for the DSM-IV anxiety disorders are somewhat lower than those estimated in the NCS-Replication,72
and resemble those reported in European epidemiologic work.73
Inclusion of the clinical significance and the substance-induced exclusion criteria in the NESARC anxiety disorder definitions may have contributed to lower rate estimates in the NESARC than the NCS-R. Also, a GAD duration criterion of 1 month or more was applied in the NCS-R rather than 6 months as specified by the DSM-IV.
This analysis has several limitations. The cross-sectional design does not permit causal inferences about DSM-IV anxiety disorders and quality of life. In addition, associations between anxiety disorders and quality of life could have been inflated by shared method variance (e.g., self-report data). Moreover, systematic survey non-response (i.e., people with greater impairment having a higher refusal rate) could have led to biased quality of life estimates, although the overall response rate for the survey was excellent and weighting procedures help to correct for non-response bias. Further, the first wave of the NESARC did not assess PTSD and OCD, precluding examination of associations of these disorders with health-related quality of life. Finally, the analysis is limited to anxiety disorders and does not address mood or other common disorders.
In this large nationally representative sample of U.S. adults, several of the DSM-IV anxiety disorders are strongly associated with decrements in social functioning, role functioning, and mental health. These observations document the heavy toll of the common anxiety disorders. Given the availability of effective interventions for anxiety disorders74–78
and documented long-delays and low treatment rates,18–19
the current findings underscore, within the U.S. context, the critical importance of accelerating the flow of affected individuals into treatment, improving clinical recognition of anxiety disorders, reducing financial barriers to effective mental health care, and maintaining a clinical focus on improving health-related quality of life.