Purpose: The present meta-analysis summarized the proportion of comorbid personality disorders (PDs) in patients with anorexia (AN) and bulimia nervosa (BN), respectively, and examined possible moderating variables.
Methods:A search of the databases PsychINFO, Embase, and Medline for the period 1980 -2016 identified 87 studies from 18 different countries.
Results:The mean proportion of PDs among patients with any type of eating disorder (ED) was .52 compared to .09 in healthy controls. There were no statistically significant differences between AN (.49) and BN (.54) in proportions of any PD or PD clusters except for obsessive compulsive PD (.23 vs .12 in AN and BN respectively).Conclusions: Both ED diagnoses had a similar comorbidity profile with a high prevalence of borderline and avoidant PDs. Moderator analyses conducted for any ED and any PD yielded significant differences for diagnostic systems with respect to EDs, method for assessing PD as well as patient weight and age.Keywords: personality disorders, anorexia nervosa, bulimia nervosa, meta-analysis, comorbidity Running head: EATING-AND PERSONALITY DISORDERS 3The Comorbidity of Personality Disorders in Eating Disorders: A Meta-Analysis Eating disorders (EDs), notably anorexia (AN) and bulimia nervosa (BN), are characterized by self-inflicted weight loss and recurrent episodes of bingeing and purging,respectively. An irrational overvaluation of the importance of controlling food, weight, and body shape represent the specific clinical features [1]. Severe EDs impair quality of life and interpersonal relations [2], and increase the number of productive years lost to disability [3].The standardized mortality rate is about five times higher than in the general population [4,5], and it takes six to nine years before 70% of the patients no longer meet the diagnostic criteria for an ED [6,7].Comorbid personality disorders (PDs) are frequently encountered in the treatment of EDs, and may become as protracted and impairing as the EDs. Previous studies [8][9][10] show that a comorbid borderline, avoidant, or obsessive-compulsive PD may worsen the long-term treatment-outcome of EDs. Moreover, a comorbid PD may complicate treatment challenges by increasing the risk of premature treatment termination due to a fragile therapeutic alliance [9,11], prolonging treatment for non-therapeutic reasons [12][13][14] or resulting in insufficient focus on alleviating ED-symptoms due to the need to address the PD. However, there are inconsistent findings from studies [15,16] and reviews [17,18] as to whether a concurrent PD predicts a poor outcome of an ED, whether PDs improve at the same rate as the ED or tend to persist after the alleviation of ED symptoms [19][20][21][22].In order to develop and examine comprehensive treatment models in terms of their cost-effectiveness, ability to overcome treatment challenges, and to prevent an unfavourable ED outcome, it is essential to determine how frequently or likely comorbid PDs are expected to appear in EDs. Research to date h...