Anorexia nervosa (AN) is classified within eating disorders (ED) and it is defined by the restriction of food intake, producing a marked decrease in weight (which reaches values below the minimum expected by sex and age), and it is accompanied by a permanent fear of increasing weight and persistent concerns about body image (American Psychiatric Association, APA, 2013). Bulimia nervosa (BN) is also included within the eating disorders group, and characterized by repeated episodes of excessive intake that occur in a short period of time (binges) and are accompanied by control behaviors weight (usually vomiting, fasting, intense exercise, use of laxatives and/or diuretics). BN shares the same dysfunctional concerns that AN about image and weight (recurrent feelings of body dissatisfaction and fear of gaining weight appear), but BN patients usually present weight into the normal range (APA, 2013). Both AN and BN disorders profiles show significant psychosocial impairment and severe medical complications (both physical and psychological), which can lead to an increased risk of suicide (Arcelus et al., 2011; Jenkins et al., 2011).
The prevalence of eating disorders varies depending on the geographic areas. In Europe, the rates obtained in cross-sectional studies for AN are between 1% and 4%, while for BN are into the range 1–2% (Keski-Rahkonen & Mustelin, 2016). In North America, the presence of AN is identified in the general population between 1% and 4.2% (APA, 2006) and between 0.5% and 1.0% for BN (NICE, 2004). In South America, epidemiological data is more imprecise, largely as a consequence of empirical studies (Mérida-Pérez & López-Hartmann, 2013): studies carried out in Argentina have published incidences between 2 and 8% for AN and BN; in Colombia around 2% (Colombo, 2006); and in Bolivia around 2.6% for AN and 4.7% for BN (Freudental, 2000). However, it should be clarified that many of the published studies are carried out in high-risk populations formed mainly by young women, which could be overestimating the real prevalence in the general population.
Anxiety problems are frequently comorbid with ED (Brytek-Matera, 2008; Solano & Cano, 2012; Swinbourne et al., 2012). Bulik (2002) noted that women with AN usually present anxiety symptoms related to the body weight and also to food behaviors. One of the anxiety disorders with the highest concurrence with AN is generalized anxiety disorder (Godier & Park, 2015; Woodside & Staab, 2006; Godart et al., 2003; Bulik, 2002). Furthermore, it has been observed that anxiety is not only a concurrent-comorbid state with eating disorders (Egan et al., 2013; Becker, DeViva & Zayfert, 2004), but also a mediating link with the high perfectionism trait that usually characterizes AN and BN patients (Egan et al., 2013; Rivière & Douilliez, 2017). For example, the Fairburn, Cooper & Shafran (2003) model indicates that perfectionism is a maintenance mechanism of eating disorders, which, modulated by anxiety levels, acts as a risk factor for an overestimation of diet as a determining factor of body composition and weight. On the other hand, empirical research focused on the psychological factors involved in the factors related with the progression and maintenance of eating disorders have also point to the important role of anxiety, which seem achieve a relevant role in the prevention and treatment programs (Rivière & Douilliez, 2017). In population-based samples, Montenegro, Blanco, Almengor & Pereira (2009) have observed the presence of a positive correlation between high levels of anxiety and greater severity of the eating disorders (concretely, in university students from Costa Rica). Other research carried out with Mexican university students found that anxiety components are crucial for the onset and the course of AN, but not for BN (within the BN condition, the contribution of anxiety is interacting with sex and with age of menarche) (Pineda-García et al., 2014). Finally, Unikel et al. (2010) observed that the presence and the way in which the risk factors for eating disorders (including anxiety) largely depend on the geographical areas.
Comorbidity studies in the eating disorders area have also identified the important role of mood symptoms for the presence and progression of both AN and BN (Hudson et al., 2007; Kaye et al., 2004), mainly depression (Tseng & Hu, 2012; Fischer et al., 2008), but also negative emotional states (Engel et al., 2005; Waller et al., 2003; Allen et al., 1998; Stice et al., al., 1996). In particular, it has been documented that AN and BN patients show high levels of depression compared with control samples without ED symptoms (Pyle et al., 1981; Bora & Köse, 2016; Franko et al., 2018; Hudson et al., 1987; Johnson & Larson, 1982; Kaye et al., 1986; Keck et al., 1990; Laessle et al., 1987; Lavender et al., 2015).
A current research is focused on the analysis of the emotional regulation capacities in patients with eating disorder (Claudat & Lavender, 2018; Donahue et al., 2018; Mallorquí-Bagué et al., 2017; Pisetsky et al., 2017). This construct refers to the ability of people to identify and manage emotions appropriately, which implies having the necessary skills to relate emotions, cognition and behavior (Lavender et al., 2015). Functional emotional regulation involves being able to express emotions appropriately, regulating emotions and feelings appropriately to the contextual demands, having adequate coping skills, and being able to generate positive emotions. It has been observed that different forms and levels of emotional dysregulation predict the onset and the progression of several psychopathological conditions (Aldao et al., 2010), including eating disorders (Aldao et al., 2010; Gratz & Roemer, 2004; Haynos & Fruzzetti, 2011; Lavender et al., 2015; Mennin & Fresco, 2009; Selby, Anestis, & Joiner, 2008). Concretely, patients with AN show difficulty both in recognition and regulation of their emotions (Harrison et al., 2009), and in some cases these correlates are also related with the presence of alexithymia (Westwood et al., 2017). On the other hand, patients with BN have showed compulsive episodes associated with difficulties in controlling impulsivity, which are also worse in the presence of positive and/or negative emotional states (Bongers et al., 2013; Leehr et al., 2015). BN patients have also showed that negative mood states related with impairing emotional regulation frequently precede binges (Gianini et al., 2015; Nicholls et al., 2016).
In summary, empirical studies evidence the relationships between AN and BN with psychopathological constructs such as anxiety, depression, perfectionism and emotional regulation. However, to our knowledge no studies have analyzed the underlying mechanisms/processes of these variables through models testing direct and indirect effects.
The present research aims to explore the associations between perfectionism, emotional dysregulation, anxiety, depression, sex and geographical origin with the AN and BN severity, through path analysis implemented with structural equations models.