Objective
Clinical studies suggest a familial association between panic disorder and alcohol use disorders but this relationship has not been examined in a representative community sample. The objective of this study is to examine the familial association between panic disorder and alcohol use disorders among adults in the community.
Method
Data were drawn from the NESARC, a nationally representative sample of over 43,000 adults in the United States. Rates of alcohol use disorders were examined using the family history method in first-degree relatives (FDRs) of adults with panic disorder. Analyses were adjusted for demographics, alcohol use disorders in the proband, and anxiety disorders in the FDRs.
Results
First-degree relatives of adults with panic disorder have significantly higher odds of alcohol use disorders, compared with FDRs of adults without panic disorder. These associations persist after adjusting for demographic characteristics, alcohol use disorders in the proband, and anxiety disorders in the FDR’s.
Conclusions
Consistent with findings from clinical studies, this is the first population-based study to show a familial link between panic disorder and alcohol use disorders. This association appears independent of the influence of comorbidity of alcohol use disorders and anxiety disorders, suggesting a potential familial and/or genetic pathway. Future longitudinal studies will be needed to further understand the mechanism of this observed association.
In recent years, there has been growing interest in the comorbidity of anxiety disorders and alcohol use disorders. While it was once thought that alcohol and other substance use disorders were more commonly comorbid only with depression and other mood disorders, research has increasingly shown strong and significant links between anxiety disorders and alcohol use problems (Zimmermann et al., 2003, Abram et al., 2007 and Moss et al., 2010). Panic disorder has emerged as an anxiety disorder strongly linked with alcohol use disorders; population-based studies have shown that over 37% of adults with panic disorder have lifetime alcohol abuse or dependence (Kessler et al., 2006), and several community and clinically-sampled studies have reported similar findings (e.g., Joyce et al., 1989 and Jacobi et al., 2004).
The reason for the observed link between panic disorder and alcohol use disorders is not known. The three main possibilities include: alcohol use disorders lead to the onset of panic disorder; panic disorder leads to onset of alcohol use problems, possibly via self-medication, or that there are common risk factors for the co-occurrence of both alcohol use problems and panic disorder. One possibility is that the observed comorbidity of panic disorder and alcohol use problems results from a shared familial vulnerability to both panic disorder and alcohol use problems. Several family studies have found increased rates of alcohol use problems in the first-degree relatives of panic disorder (PD) probands as compared to controls (Noyes et al., 1978, Crowe et al., 1983, Maier et al., 1993a and Maier et al., 1993b; Goldstein et al., 1994, Merikangas et al., 1994 and Merikangas et al., 1998). As such, evidence consistently suggests a familial link between PD and alcohol use disorders. Yet, several methodological features of previous studies leave questions unanswered. Specifically, with few exceptions (Maier et al., 1993a, Maier et al., 1993b and Katerndahl and Realini, 1999), the study designs of previous investigations have not considered the potentially confounding role of comorbid alcoholism in the PD proband. As alcohol use disorders have a familial component, it therefore remains unclear whether the observed increases reflect a familial association between alcoholism and PD, or are attributable to proband alcohol comorbidity. In addition, all previous studies have examined these relationships in clinical and specifically recruited treatment samples. As such, it is not clear whether findings are generalizable to those with alcohol use disorders and panic disorder in the community. As rates of PD are higher among females in the community, and alcohol use disorders are more common among males, the degree to which these patterns are gender specific in terms of familial vulnerability is unclear as this has been difficult to examine in clinical samples due to smaller sample size.
Against this background, the goal of the current study is to investigate the familial association between PD and alcohol use disorders among adults in the community. First, the study will examine whether there are higher rates of alcohol use problems among first-degree relatives of adults with panic disorder as compared to relatives of non-PD controls. Second, the study will examine the degree to which the familial link between PD and alcohol use disorders is explained by comorbid mental disorders or demographic differences. Third, the study will examine whether the familial link between PD and alcohol use problems differs by gender, as a previous clinical study (e.g., Goodwin et al., 2006) found significantly higher rates of alcohol use disorders in males, but not females, of PD probands though the patterns were similar so it was unclear whether this is a meaningful sex difference or due to smaller sample size. Based on clinical findings (Noyes et al., 1978, Crowe et al., 1983, Maier et al., 1993a, Maier et al., 1993b, Goldstein et al., 1994, Merikangas et al., 1994, Merikangas et al., 1998 and Goodwin et al., 2006), we hypothesized that there would be an elevated risk of alcohol use disorders among first-degree relatives of adults with PD. We predicted that this link would persist after adjusting for both alcohol use disorders in the proband, and other comorbid mental disorders.
