Social anxiety disorder (SAD) is associated with high rates of alcohol use disorders.[1
] Almost half of individuals with DSM-IV lifetime SAD meet criteria for lifetime prevalence of an AUD[2
] compared to 18.6%[3
] in the general population. Furthermore, the 12-month prevalence of AUD among SAD individuals is 13.1%[2
] versus 8.5% among the general population.[4
] Among patients seeking treatment for alcohol-related problems, 23–39% meet diagnostic criteria for SAD.[5
] SAD appears to be associated with increased risk of alcohol dependence
more so than abuse[2
] suggesting that SAD is linked to a risk of greater alcohol-related impairment. Among the anxiety disorders, SAD shows a particularly problematic risk profile for comorbid AUD, as SAD is associated with higher rates of AUD relative to most other anxiety disorders[10
] and adolescent SAD (but not other anxiety or mood disorders) appears to serve as a risk for adult alcohol dependence.[9
Despite the high comorbidity rates between SAD and AUD, the extant literature linking AUD to SAD is limited in a number of ways. First, the impact of AUD on SAD is understudied as little empirical attention has focused on how individuals with comorbid SAD–AUD differ from unimorbid cases. Second, earlier work examining differences between unimorbid and comorbid individuals has been limited to treatment settings and information about the impact of comorbidity among non-treatment samples is limited. A third limitation in the extant literature is that the temporal relationship between SAD and AUD has not been fully elucidated so it is currently unclear whether SAD predicts later AUD or vice versa. Fourth, the majority of studies in this area tend to combine alcohol abuse and alcohol dependence diagnoses, making it difficult, if not impossible, to demarcate whether individuals with SAD are at increased risk for alcohol abuse or dependence. A fifth limitation to the extant literature is that little attention has been paid to the role of other types of psychopathology in the relation between SAD and AUD.[10
We know of no systematic examination of the impact of AUD on individuals with SAD. The few studies examining this question indicate that the high rates of comorbidity between SAD and AUD are associated with greater impairment than either disorder without the other. For instance, among treatment-seeking participants in Project MATCH,[11
] patients with current AUD and a lifetime diagnosis of SAD were more likely to have major depressive episodes, experience more severe alcohol dependence and exhibit lower occupational status and less perceived peer social support than patients with AUD without SAD.[8
] Similarly, when compared to patients with SAD and no history of AUD, patients with current SAD and a lifetime history of AUD have been found to exhibit more severe SAD symptoms and are less likely to be married, indicating relative impairments in interpersonal functioning.[6
] However, several critical domains have not been explored. Regardless of comorbidity, SAD in and of itself is associated with increased personal and societal costs. To illustrate, SAD is associated with impairment in mental and physical health as evidenced by high rates of comorbidity with other anxiety and mood disorders[13
] and reports of poor perceived physical health.[14
] Approximately 22% of individuals with SAD receive public assistance.[13
] Relative to unimorbid cases, individuals with SAD and other comorbid conditions have reported greater impairment in mental and physical health and to be more likely to inform a health care provider of their condition.[15
] If, compared to unimorbid cases, individuals with both SAD and AUD also experience greater rates of other psychopathology and physical health problems as well as engage in increased health care utilization, public health costs could be even greater for this group.
The work that has examined the impact of comorbidity on those with unimorbid SAD or AUD has examined these relations in treatment settings.[6
] We could find no reports regarding the impact on functioning of AUD comorbidity among individuals in the general population who may not be in treatment. Given that epidemiological data indicate that 80–95% of people with SAD report receiving no
] patterns observed in treatment-seeking populations may or may not reflect the experiences of the majority of people with SAD. Clarification of the impact of comorbidity could contribute substantially to our understanding of the nature of this comorbidity and may inform prevention and treatment efforts. To illustrate, social support is associated with better response to AUD treatment.[16
] If individuals with comorbid SAD and AUD do in fact demonstrate poorer social support as suggested by earlier work,[6
] treatment of comorbid individuals may need to incorporate specific strategies to improve social functioning.
The temporal relations between AUD and SAD among comorbid individuals remain unclear. Evaluation of typical age of onset of SAD and AUD suggests that SAD serves as a risk factor for subsequent AUD (i.e., it precedes the future development of alcohol use problems). Mean age of onset is usually earlier for SAD than AUD among individuals with co-occurring SAD and AUD.[6
] Additionally, adolescent SAD has been found to significantly predict adult alcohol dependence.[9
] Yet, these studies typically examine mean or typical age of onset, limiting the ability to examine whether for some individuals there is a shared diathesis or even whether for some, AUD occurs before SAD. Given evidence suggesting that anxiety disorders can serve as risk for the development of AUD and that alcohol dependence appears to serve as a risk for the development of at least some anxiety disorders,[20
] the reliance on mean age of onset date may obfuscate the possibility that alcohol misuse may serve as a risk for subsequent SAD in at least some comorbid individuals. Differential temporal relations may be associated with different types of impairment. Individuals who develop SAD after AUD as a consequence of embarrassment regarding alcohol-related actives may present somewhat differently than individuals with SAD who develop AUD as a result of using alcohol to manage their social anxiety. However, to date, the relevance of differential temporal relationships remain empirically unclear and unstudied.
Similarly, it is currently unclear whether individuals with SAD are at increased risk for alcohol abuse or dependence as the few studies in this area usually combine alcohol abuse and alcohol dependence diagnoses.[6
] This distinction is important because these are unique types of substance use problems.[22
] For instance, abuse is not merely a prodromal phase of alcohol dependence but a unique condition[23
] with dependence characterized by compulsive alcohol use behaviors and/or physiological tolerance or withdrawal.[24
] Dependence seems to be a more chronic and impairing condition relative to alcohol abuse.[23
] Given evidence suggesting that individuals with SAD may be particularly vulnerable to alcohol dependence,[2
] future work is needed to more directly and definitively examine the relations between SAD and alcohol abuse and dependence.
It is also important to examine the role of other types of psychopathology in the relation between SAD and AUD as it is unknown whether SAD demonstrates a specific relationship to AUD after accounting for other types of psychopathology, including internalizing and externalizing disorders, related to alcohol problems. It may be that the high rates of AUD among individuals with SAD are simply attributable to co-occurring axis I pathology. Indeed, SAD often co-occurs with other anxiety disorders as well as depression[14
] and AUD are often prevalent in individuals with other anxiety conditions[25
] and depression.[26
] Similarly, both social anxiety and alcohol problems are related to other substances such as marijuana[29
] Externalizing disorders such as conduct disorder demonstrate high comorbidity with anxiety disorders[32
] and predict later AUD.[33
] These high rates of comorbidity suggest that the link between SAD and AUD could be attributable to other types of related psychopathology. Only one known study has evaluated whether SAD is linked to AUD above and beyond relevant axis I psychopathology.[9
] Although this study found SAD onset to be prospectively linked to subsequent AUD onset after accounting for other psychopathology, the small number of individuals in some diagnostic categories indicates further work with large representative samples is needed to examine the unique explanatory power of SAD in relation alcohol-related problems.
The present investigation contributes to the elucidation of the relationship between SAD and AUD. The first goal of this study was to replicate and extend earlier work in this area[9
] by examining the comorbidity of SAD and its specificity with AUD (i.e., abuse and dependence) after controlling for theoretically relevant variables (e.g., gender, depression, conduct disorder, other anxiety disorders) using a large epidemiological database. Consistent with earlier work,[9
] it was hypothesized that after controlling for relevant variables, SAD would be significantly related to alcohol dependence but not abuse. The second goal was to replicate and extend earlier findings[6
] that comorbid SAD and AUD is related to greater impairment relative to SAD alone. Specifically, it was predicted that, relative to individuals with SAD without alcohol dependence, people with comorbid SAD and alcohol dependence would demonstrate greater impairment across several domains including social support, mental health, physical health, and health care utilization.
The third goal of this study was to build upon past work regarding temporal patterns of AUD and SAD in several ways. Earlier work has demonstrated that mean age of onset of SAD precedes that of AUD.[10
] We strove to extend this finding by predicting that although the majority of people with comorbid SAD and AUD would demonstrate earlier age of SAD onset relative to AUD onset, some individuals would demonstrate AUD onset before SAD onset. This prediction is consistent with past findings that examine differential temporal relations with AUD in samples that combine individuals with various anxiety disorder diagnoses.[5
] In addition, we investigated whether unimorbid individuals’ age of SAD and AUD onset differed from those with comorbid SAD and AUD. It was hypothesized that comorbid cases would exhibit earlier age of onset relative to unimorbid SAD but, consistent with earlier work,[8
] not unimorbid AUD cases. Finally, we examined whether individuals with SAD before AUD differed from individuals with AUD before SAD in terms of demographics and level of impairment (in areas of social support, mental health, physical health, and health care utilization). On the basis of earlier work with panic-prone substance users,[34
] we hypothesized these two groups to differ. Specifically, consistent with the notion that people with SAD before AUD would demonstrate earlier age of onset and a more chronic course of psychopathology, it was hypothesized that this group would demonstrate greater impairment.