Women with eating disorders have a significantly higher prevalence of substance use disorders than the general population. The goal of the current study was to assess the temporal pattern of comorbid anorexia nervosa (AN) and alcohol use disorder (AUD) and the impact this ordering has on symptomatology and associated features. Women were placed into one of three groups based on the presence or absence of comorbid AUD and the order of AN and AUD onset in those with both disorders: (1) AN Only, (2) AN First, and (3) AUD First. The groups were compared on psychological symptoms and personality characteristics often associated with AN, AUD, or both using general linear models. Twenty-one percent of women (n = 161) with AN reported a history of AUD with 115 reporting AN onset first and 35 reporting AUD onset first. Women with binge-eating and/or purging type AN were significantly more likely to have AUD. In general, differences were found only between women with AN Only and women with AN and AUD regardless of order of emergence. Women with AN and AUD had higher impulsivity scores and higher prevalence of depression and borderline personality disorder than women with AN Only. Women with AN First scored higher on traits commonly associated with AN, whereas women with comorbid AN and AUD displayed elevations in traits more commonly associated with AUD. Results do not indicate a distinct pattern of symptomatology in comorbid AN and AUD based on the temporal sequence of the disorders.
The National Center on Addiction and Substance Abuse reports that up to 50% of individuals with an eating disorder abuse substances compared with 9% of the general population, and up to 35% of individuals with substance abuse have an eating disorder compared with 3% of the general population (CASA, 2003). The association between substance abuse and eating disorders is thought to be strongest with bulimia nervosa (BN) (Gadalla and Piran, 2007, Harrop and Marlatt, 2010 and Holderness et al., 1994). However, substance use disorders, including alcohol use disorders (AUD), also occur in women with anorexia nervosa (AN) (Baker et al., 2010, Bulik et al., 2004, Root et al., 2010 and Root et al., 2010). For example, a recent population-based study indicated that approximately 22% of women with AN have a lifetime history of AUD (Baker et al., 2010). Although the association between AUD and AN is strongest with AN binge-purge type, the prevalence of AUD in women with AN restricting-type is greater than that found in the general population (Root, Pinheiro, et al., 2010). However, to date, the temporal sequence of comorbid AN and AUD has not been thoroughly examined.
Longitudinal studies indicate that women who initially present with an eating disorder are at risk for AUD over a prolonged period of time. Over the course of nine years, Franko and colleagues (Franko et al., 2005) found that 10% of women with an eating disorder reported onset of AUD after their initial presentation for eating disorder treatment. Similarly, in a 10-year follow-up of male and female adolescents (90% female) hospitalized for AN, 8% developed a new onset AUD (Strober, Freeman, Bower, & Rigali, 1996). The association and risk for comorbid AN and AUD is particularly important as there is substantial mortality in women with this comorbid presentation (Keel et al., 2003 and Suzuki et al., 2011).
Of those women with comorbid AN and AUD, approximately 50% report AN onset prior to AUD onset whereas approximately 30% report AUD onset prior to AN onset (Baker et al., 2010 and Bulik et al., 2004). Yet, few large-scale studies have addressed how chronology of onset influences the nature of symptoms, associated features, and additional comorbidities. One study revealed that AUD onset prior to AN onset is associated with increased reports of parental criticism (Bulik et al., 2004). Women with comorbid AN and AUD also report increased motor impulsivity, perfectionism, and parental criticism and expectations as well as greater frequency of major depressive disorder, obsessive compulsive disorder, post-traumatic stress disorder, social phobia, specific phobias, and borderline personality disorder (Bulik et al., 2004 and Wiseman et al., 1999).
Further clarifying whether AN or AUD develops first in their temporal sequence may provide information on differential mechanisms of comorbid association, unique mechanisms of causation, insight into symptom heterogeneity, and inform differential treatment approaches. For example, heterogeneity of causal mechanisms is likely as women with AN first may subsequently turn to alcohol to dampen the physical effects of starvation and restriction (Bulik et al., 2004, Godart et al., 2000 and Harrop and Marlatt, 2010), whereas women who develop AUD first may find the initial weight loss that can occur secondary to decreased food caloric intake and increased alcohol caloric intake rewarding (Liangpunsakul, 2010, Lieber, 1991 and Reinus et al., 1989). Finally, the symptom profile of each disorder could differ depending on chronology of onset, which could also inform treatment approaches.
The objectives of the present study are four-fold: (1) to assess the prevalence of comorbid AN and AUD in women by AN subtype; (2) to examine whether the ages of onset of AN and AUD differ in women with AN Only, AN First, and AUD First; (3) to determine whether AN-related symptom endorsement differs in women with AN Only, AN First, and AUD First; and (4) to investigate differences in personality characteristics and prevalence of other psychiatric disorders based on the presence or absence of AUD as well as order of onset in women with both AN and AUD.
