While evidence continues to accumulate on the relevance of cognitive inflexibility in anorexia nervosa (AN), its clinical correlates remain unclear. We aimed at examining the relationship between set-shifting and clinical variables (i.e., eating psychopathology, depression, and personality) in AN. Ninety-four individuals affected by AN and 59 healthy controls (HC) were recruited. All participants were assessed using: Eating Disorders Inventory-2 (EDI-2), Temperament and Character Inventory (TCI), Beck Depression Inventory (BDI), and Wisconsin Card Sorting Test (WCST). The AN group scored worse than HCs on set-shifting. According to their neuropsychological performances, AN patients were split into two groups corresponding to poor (N=30) and intact (N=64) set-shifting subtypes. Interoceptive awareness, impulse regulation, and maturity fears on the EDI-2 and depression on the BDI differed across all groups (HC, intact, and poor set-shifting subtype). Self-directedness on the TCI differed significantly among all groups. Cooperativeness and reward dependence differed instead only between HC and AN poor set-shifting subtype. After controlling for depression, only interoceptive awareness remained significant with reward dependence showing a trend towards statistical significance. These findings suggest that multiple clinical variables may be correlated with set-shifting performances in AN. The factors contributing to impaired cognitive inflexibility could be more complex than heretofore generally considered.
Anorexia nervosa (AN), is a severe psychiatric illness characterized by restricted eating, relentless pursuit of thinness, and obsessive fears of becoming fat in spite of life-threatening underweight (Yager et al., 2012). Several lines of evidence suggest that some clinical aspects of AN could mirror alterations of cognitive functions; in particular, those rigid and perfectionistic features that usually characterize affected individuals could be the result of set-shifting inefficiencies (Roberts et al., 2007).
In more detail, cognitive flexibility or set-shifting refers to the process of “shifting” and moving back and forth between different cognitive strategies and behaviors in response to changes in the environment. This cognitive ability has been found to be altered with a high degree of consistency in adults with AN (Tchanturia et al., 2011 and Tchanturia et al., 2012; Galimberti et al., 2013; for a review see Jáuregui-Lobera (2013). Interestingly, our group (Abbate-Daga et al., 2011) demonstrated that adult AN patients are rigid not only in verbal but also in non-verbal domains, as recently confirmed (Pignatti and Bernasconi, 2013). Still, cognitive alterations have been found to play a role not only as vulnerability and maintaining factors but also as biological markers (Steinglass et al., 2006, Galimberti et al., 2012 and Roberts et al., 2013).
Notwithstanding the body of evidence supporting cognitive inflexibility in AN, several aspects are still far from being conclusive. First, altered set-shifting is very common in adults diagnosed with AN although it does not characterize all affected individuals (Rose et al., 2012). Second, the role of depression on neuropsychological performances remains unclear although a clarification of this issue would be much needed (Giel et al., 2012) also given its frequent comorbidity with AN (O’Brien and Vincent, 2003). In fact, some studies failed to find an effect of depressive comorbidity on neuropsychological aspects (Sarrar et al., 2011, Calderoni et al., 2013 and Sato et al., 2013) but the majority of the studies did not take comorbidity into account.
In addition to comorbidity, evidence accumulated on the key-role of personality in EDs (Amianto et al., 2011, Lilenfeld, 2011 and Keel and Forney, 2013). Studies using the Temperament and Character Inventory (TCI; Cloninger et al., 1993) demonstrated that individuals with Eating Disorders (EDs) tend to be inhibited (high harm avoidance), perseverative (high persistence) and with low self-directedness (Fassino et al., 2004 and Lilenfeld, 2011). Additionally, a “maladaptive” profile (Krug et al., 2011) characterizes a subgroup of patients with low reward dependence. However, to date the influence of personality on neuropsychological performances has received only scant attention.
Perfectionism represents a vulnerability and maintaining factor for different mental disorders including EDs (Egan et al., 2011) but its relationship with set-shifting is still far from being conclusive, particularly as regards AN (Pignatti and Bernasconi, 2013). To date, perfectionistic traits have been found not only to be positively related to cognitive rigidity (Ferrari and Mautz, 1997 and Bühren et al., 2012) but also to play a role in action monitoring in depressed samples (Schrijvers et al., 2010). Individuals affected by Obsessive–Compulsive Disorder (OCD) tend to be characterized by both perfectionism and sub-optimal set-shifting abilities (Cavedini et al., 2010, Bradbury et al., 2011 and Demeter et al., 2013) raising the hypothesis that perfectionistic personality traits could underpin both AN symptomatology and poor set-shifting abilities (Friederich and Herzog, 2011). From a clinical standpoint, such personality traits are of particular interest since associated with negative outcomes (Crane et al., 2007) and possible mediators in the treatment of AN (Lock et al., 2005).
This study aims to further understand the cognitive profile of set-shifting in AN. Adopting a methodology already used in the field (Roberts et al., 2010) we aim at identifying those clinical features and personality traits that could be associated with poor versus intact set-shifting.
Our a priori hypothesis was that poor set-shifting in AN could be associated with more severe perfectionistic personality traits, eating psychopathology and depressive symptoms, independently from nutritional status.
