The Links Between PTSD and Eating Disorders

Despite an abundance of studies linking both traumatic experiences and anxiety disorders with eating disorders, relatively little has been reported on the prevalence of associated posttraumatic stress disorder (PTSD) or partial PTSD in patients with eating disorders. The National Women's Study, dating back more than 10 years, remains the only detailed study of crime victimization histories, resultant PTSD, and associated psychiatric comorbidity, including eating disorders, in a representative sample of women in the United States.¹ This article presents the case for a link between PTSD and eating disorders. The prevalence of comorbid PTSD and eating disorders is discussed with an explanation of a mechanism that may explain the connection, followed by treatment options and reasons for caution.

Prevalence
In the National Women's Study, both current and lifetime PTSD prevalence were found to be significantly higher in persons with bulimia nervosa than in those without bulimia nervosa (current: 21% vs 4%, P < .001; lifetime: 37% vs 12%, P < .001). Those who met DSM-IV criteria for binge eating disorder also had a significantly higher lifetime prevalence of PTSD (22%) compared with control participants (P < .01), although there was no significant difference in current PTSD prevalence. One of the critical findings from this study was that prevalence of bulimia nervosa was significantly greater in individuals with histories of rape with PTSD (10.4%) than in those with histories of rape without PTSD (2.0%) and in those with no history of rape (2.0%). These findings strongly imply that it is abuse resulting in PTSD (rather than abuse per se) that significantly increases the chances of later developing bulimia nervosa.² Lifetime PTSD also predicted the associated comorbidities of major depression and alcohol(Drug information on alcohol) abuse/dependence with bulimia nervosa.³ None of the study participants with anorexia nervosa had a history of PTSD.

Studies of clinical samples also indicate higher than expected rates of PTSD in patients with eating disorders. In one report, 74% of 293 women attending residential treatment indicated that they had experienced a significant trauma, and 52% reported symptoms consistent with a diagnosis of current PTSD based on their responses on a PTSD symptom scale.⁴ Forty-seven percent of 112 patients with anorexia nervosa and 62% of patients with bulimia nervosa met PTSD criteria. It was not clear from this study what percentage of the anorexia nervosa patients also binged and/or purged. However, taken together, the overall research literature has linked histories of trauma and PTSD with bulimic disorders, including bulimia nervosa, binge eating disorder, and anorexia nervosa of the binge-eating/purging type, as opposed to anorexia nervosa of the restricting type.^2,5-9

In a clinical sample of 44 patients who recovered from bulima nervosa, 20 abused patients showed a trend toward more frequent diagnoses of PTSD over their life span and more frequent substance dependence than did the 24 nonabused patients.¹⁰ Lipschitz and colleagues¹¹ reported on the associated comorbidity among 74 adolescent inpatients. PTSD was the most common diagnosis (36%), and eating disorders were significantly more frequent in the PTSD group (25%) than in the non-PTSD group (6%, P < .03). In addition, hospitalized adolescent males with PTSD were more likely to have comorbid eating disorders, other anxiety disorders, and somatization. Unfortunately, the types of eating disorders in these patients were not described.

In a large national sample of 24,041 hospitalized female veterans, those inpatients with an eating disorder diagnosis had higher rates of anxiety disorders, especially PTSD, as well as borderline personality disorder (BPD).¹² The point prevalence of PTSD in women inpatients with an eating disorder was 25% compared with 8% in inpatients who did not have an eating disorder. The authors noted that there was very little overlap between those with PTSD and BPD in that only 12.5% of the inpatients with BPD also had a diagnosis of PTSD.

In a study of 2436 women at a long-term residential treatment center, the rates of PTSD significantly differed across eating disorder diagnoses (P < .05), with the highest rates occurring in patients with anorexia nervosa binge-eating/purging type (25%) and the lowest rates occurring in patients with anorexia nervosa restricting type (10%). Intermediate PTSD rates were found in those with bulimia nervosa (23%) and in those with eating disorder not otherwise specified (23%).¹³

Thompson and associates¹⁴ investigated rates of PTSD symptoms and other psychopathology in 97 women who: (1) had been sexually abused in childhood only; (2) had been raped in adulthood only; (3) had been both sexually abused during childhood and raped during adulthood; or (4) had never been sexually abused. All participants were assessed using the Structured Clinical Interview for DSM-IV and the Modified PTSD Symptom Scale Self-Report. Women who reported sexual trauma, regardless of age, were significantly more likely to exhibit psychopathology than controls, including higher rates of both PTSD and eating disorders. Rates of PTSD diagnosis were 6 to 7 times higher in the 3 trauma groups than in the control group, and rates of an eating disorder diagnosis were 5 times higher.

In a study of 257 female patients evaluated at an anxiety disorders clinic who had principal diagnoses of an anxiety disorder (PTSD, generalized anxiety disorder, panic disorder, obsessive-compulsive disorder, or so-cial phobia), only PTSD and social phobia were significantly related to eating disorder symptoms. These 2 anxiety disorders accounted for significant, unique variance in eating disorder pathology.¹⁵