July 5, 2011 — Although anorexia nervosa (AN) and posttraumatic stress disorder (PTSD) are often comorbidities in adults, traumatic events that can lead to PTSD usually occur before the onset of AN, new research suggests.
A secondary analysis study of more than 700 women with AN also showed that the most common traumatic event reported by those with concurrent PTSD was a sexually related trauma experienced in either childhood or adulthood.
"These results underscore the importance of assessing trauma history and PTSD in individuals with AN and raise the question of whether specific modifications or augmentations to standard treatment for AN should be considered," write the investigators.
"We are always looking for associations with anorexia that might help in determining factors that contribute to its onset," study investigator Laura M. Thornton, PhD, research associate professor in the Department of Psychiatry at the University of North Carolina in Chapel Hill, told Medscape Medical News.
However, she noted that the findings did not determine causation but merely point to an association. Stressful life events that occur early may be related to the onset of AN and PTSD, she said. However, more research needs to be conducted before any definitive conclusions can be drawn.
The study was published online June 28 in Psychosomatic Medicine.
Impulsivity and Obsessions
For the analysis, investigators evaluated data on 753 females older than 16 years (mean age, 29.5 years) with AN who participated in the Genetics of Anorexia Nervosa Collaborative study.
The Structured Interview for AN and Bulimic Syndromes and the Yale-Brown-Cornell Eating Disorder Scale (YBC-EDS) were administered to all participants, who were also evaluated for one of the following AN subtypes:
Restrictive behaviors with no binge eating or purging behaviors (RAN);
Purging without binge eating (PAN);
Binge eating without purging (BAN); and
Both AN and bulimia nervosa (ANBN).
Other measurements included the State-Trait Anxiety Inventory Form Y, the Multidimensional Perfectionism Scale, and the Temperament and Character Inventory. PTSD was assessed using the Structural Clinical Interview for Axis I Disorders for those who reported having experienced a traumatic event.
Results showed that 39% of the women had experienced 1 or more traumatic events over their lifetime. However, only 13.7% of the total participants met the criteria for a PTSD diagnosis.
PTSD was found in 18.4% of the women with PAN, 16.5% of those with BAN, 12.4% of those with ANBN, and 9.9% of those with RAN.
The researchers explain that these differences in PTSD prevalence may, in part, be because previous research has shown that those with BAN and PAN have greater impulsivity than those with RAN — and impulsivity has been linked with both trauma and PTSD.
"Some specific behaviors of eating disorder (binge eating and purging) associated with impulsivity could be mechanisms to avoid awareness of the trauma," they write.
In addition, the researchers found that the odds of having a PTSD diagnosis were significantly lower in the participants with RAN than those with PAN (odds ratio, 0.49; 95% confidence interval, 0.30 – 0.80). No other differences were found to be significant.
A total of 64.1% of those with PTSD reported experiencing their first traumatic event before the onset of their AN, with the most common event being sexual abuse between the ages of 6 and 17 years (40.8%) and sexual abuse or rape when older than 18 years (35.0%). The death or serious illness of a loved one was cited by 17.5%.
Finally, the only association found between AN characteristic and risk for PTSD was food obsessions total score from the YBC-EDS (adjusted relative risk, 1.08).
The researchers note that a 1-unit increase in the score resulted in a 6.7% increase in probability of PTSD (P < .006).
"Because impulsivity and obsessions related to trauma have been associated with treatment resistance, suicide risk, and self-destructive behaviors, the treatment of AN patients with comorbid PTSD may benefit from focused attention to address [these] features," they note.
Evaluation of PTSD Important
"I think this is an important study that tries to address what some of the factors are that make the treatment of this condition so challenging," David Herzog, MD, Harvard Medical School Endowed Professor of Psychiatry in the field of eating disorders and director of the Harris Center for Education and Advocacy in Eating Disorders at Massachusetts General Hospital in Boston, told Medscape Medical News.
"There's been no specific treatment that's been effective for adults with [AN], and we're always trying to figure out how we can better understand this disorder, which is why looking at its association with PTSD is so interesting," Dr. Herzog added.
He noted that although only a portion of patients with AN will have PTSD, "it's not a tiny percentage, as shown in this study."
He also called the study's researchers "an unbelievable team of investigators, who are leaders in the field."
However, some limitations he cited included that this was not originally designed to specifically assess PTSD but was actually a genetics study and that there could have been some recall bias in regard to the traumatic events.
"Still, my recommendation would be that PTSD needs to be evaluated as part of an assessment of any individual with anorexia nervosa. And that's not just at the first visit. As the therapeutic relationship evolves, information may be provided that would then have an important role in developing an appropriate treatment strategy," Dr. Herzog concluded.
The study was funded by a grant from the National Institutes of Health. One of the study authors reports receiving support from the Franklin Mint Endowed Chair in Eating Disorders and another reported receiving support from grants from the National Institute of Mental Health. The other study authors and Dr. Herzog have disclosed no relevant financial relationships.
Psychosom Med. Published online June 28, 2011. Abstract
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Cite this: Psychological Trauma Linked to Anorexia Onset - Medscape - Jul 05, 2011.