Objective
Pathological gambling (PG) and eating disorders (ED) rarely co-occur. We explored the prevalence of lifetime PG in ED, compared severity of ED symptoms, personality traits, and psychopathological profiles across individuals with ED and PG (ED + PG) and without PG (ED-PG). Finally, we assessed the incremental predictive value of gender on the presentation of a comorbid PG.
Method
A total sample of 1681 consecutively admitted ED patients (1576 females and 105 males), participated in the current study (25 ED + PG and 1656 ED-PG). All participants were diagnosed according to DSM-IV criteria. Assessment measures included the Symptom Checklist and the Temperament and Character Inventory-Revised, as well as other clinical and psychopathological indices.
Results
The observed lifetime prevalence of PG was 1.49%. ED subtype was associated with lifetime PG (p = .003), with PG being more frequent in binge eating disorder (5.7%). ED + PG was more prevalent in males than in females (16% vs. 1.26%, respectively). Additionally, ED + PG patients exhibited more impulsive behaviours, lower impulse regulation and higher novelty seeking. Best predictors of ED + PG were novelty seeking (OR 1.030, p = .035), sex (OR 3.295, p = .048) and BMI (OR 1.081, p = .005).
Conclusions
Some personality traits (novelty seeking), being male and higher BMI are strongly related to the presence of lifetime PG in specific ED subtypes (namely binge eating disorder).
Pathological gambling (PG) is a disorder characterized by persistent and recurrent maladaptive patterns of gambling behavior and is classified as an impulse control disorder (ICD) in DSM-IV [1]. Impulsivity has been identified as a trait that underlies vulnerability to binge eating, problem drinking, and problem gambling [2].
In individuals with eating disorders (ED), lifetime comorbid ICDs have a prevalence of 16–23.8%, with the most frequently reported disorders being compulsive buying and kleptomania [3], [4] and [5]. Tobacco and drug use is also reported to be elevated in eating disorders [6]. Individuals suffering from anorexia nervosa (AN) and bulimia nervosa (BN) are more prone to committing suicide [7] and [8]. Suicide is reported to be the major cause of death in AN [9] and to have 26.9% lifetime prevalence in BN, being influenced by the combination of internalizing personality traits and impulsivity [10].
A substantial proportion of bulimic women (20%) exhibit problems with impulse control that extend beyond the impulsivity inherent in binge eating: they display other impulsive behaviors that may have serious medical complications and legal ramifications (e.g., stealing, self-injury, attempted suicide, drug and alcohol abuse, laxative abuse, and sexual promiscuity) [11].
The presence of multi-impulsivity in individuals with BN is associated with more severe clinical features, such as concurrent depressive and anxious symptoms, poor global functioning, and higher prevalence of borderline personality disorder [12]. Genetic findings indicate that women with BN who are GG homozygotes on the _1438G/A promoter polymorphism are more impulsive and have lower sensitivity to post-synaptic serotonin activation. These findings associate the GG genotype with impulsivity and post-synaptic 5-HT function in women with active BN [13].
An examination of the relationship between ED and PG reveals that although there are shared personality traits between individuals with BN and PG when compared with healthy controls, there are certain sex- and diagnostic-specific personality traits that make BN different from other ICDs [14]. It appears that gambling is associated with higher impulsivity in men, whereas in women, binge eating is strongly driven by the desire to relieve negative affect [2]. However, few studies have addressed the link between BN and PG, nor has the prevalence of PG in ED been ascertained.
The goals of the present study were: 1) to identify the prevalence of lifetime PG in a clinical sample of individuals with ED diagnostic subtypes; 2) to analyze whether ED patients with lifetime PG exhibit more severe eating disorder symptomatology, more maladaptive personality profiles and greater general psychopathology than ED patients without PG; 3) and 4) to assess the incremental predictive value of gender on the presentation of a comorbid PG.
We hypothesized that the prevalence of PG in an ED sample will be greater than in general population, given the shared vulnerability factors between both disorders, and it will be especially higher in BN and BED subtypes. We also hypothesized that those patients who present lifetime PG will show greater clinical severity. Finally, in agreement with the literature, we also hypothesized that PG lifetime in ED patients will be a gender specific trait, being more prevalent in ED males.
Pathological gambling is characterized by a failure to resist an impulse, drive, or temptation to perform an act that is harmful to self or others. Researchers have hypothesized that ICDs lie along an impulsive-compulsive spectrum. This clinical description might also be applicable to some symptoms of eating disorders, especially bulimia nervosa and binge eating disorder. Despite the acknowledgement of shared vulnerabilities, the relationship between ICDs and ED has been rarely explored. The fact that PG is more frequent in males whereas ED are more frequent in women, may explain why few studies have analyzed the comorbidity between them. Although we found a PG prevalence among ED patients comparable to the rate observed in the general population, when considering gender and ED subtype, we observed a higher than expected prevalence of PG in males with BED. Furthermore, our results indicated that the best predictors of ED + PG were sex, BMI and novelty seeking. To summarize, our findings suggest the need to explore comorbid impulse control disorders in patients with ED to adapt the treatment to the clinical characteristics of individual patients. Unrecognized and untreated PG could have a negative effect on the course and response to treatment in ED.
