The correlation between eating disorders and other psychological disorders
is very important for our understanding of the causes and possible treatments
for eating disorders. It is known that many people with eating disorders
also fit the criteria for several DSM-IV psychological disorders. If researchers
can find patterns of comorbidity between these two types of disorders they
may be able to better diagnose and treat patients with both of these disorders.
The question that I pose it what is the relationship between eating disorders
and personality disorders(axis 11 disorders in DSM-IV)? It is important
to look for comorbidity between the two disorders to determine the impact
they have on each other. Once we understand their relationship we may be
able to prevent one disorder by treating the other or maybe use the same
type of therapy to treat both. In order to answer the question posed I
have reviewed several major research articles on the prevalence and comorbidity
of personality disorders and eating disorders.
Personality disorders fall under axis 11 of the DSM-IV. This section
includes borderline, schizoid, paranoid, antisocial, narcissistic, obsessive-compulsive
and avoidant disorders. There are several disorders included in axis 11
but for our purposes we will mostly be dealing with the disorders listed
above. The most common personality disorder found among patients with eating
disorders is borderline disorder. The majority of the research deals with
borderline disorder, a disorder that is characterized by "vulnerability
to a range of impulsive behaviors (overeating, shoplifting, substance abuse)
and a history of self-destructive behavior, including suicidal gestures
and self-mutilation. They show affective instability marked by rapid fluctuations
of moods ranging from intense irritability and anger to profound feelings
of depression, emptiness and boredom."(Johnson, 1989, p.9).
In a majority of the research articles studies were done on both patients
with anorexia nervosa and patients with bulimia nervosa. During the research,
as we will see, there was some difference in the comorbidity of personality
disorders depending on whether the subjects were anorexic or bulimic.
Unfortunately there are no clear cut answers to the question posed at the beginning of this article. The main reason, which I will describe later, has to due with the broad range of analisation techniques used by researchers in defining and determining the rate and impact of comorbidity. There isn't any question that there is a great deal of comorbidity between eating disorders and personality disorders because most of the research done has found some correlation. The question remains as to how much of a correlation there is and what effect the personality disorders have on eating disorders. In order to examine this closer it is helpful to look at the results of several major experiments.
In this experiment 94 consecutive patients seeking treatment for eating
disorders were evaluated for several other psychological problems including
the prevalence of borderline disorder. 25% of the patients met the criteria
for borderline personality disorder. These patients had relatively few
differences in the their patterns of eating behaviors and attitudes when
compared with nonborderline patients. The borderline patients were more
disturbed on several other relevant emotional factors. The only aspect
of eating behavior that varied between the two groups was that significantly
more borderline patients reported having used laxatives and abused them
as a form of purging. There was no difference found in the frequency of
binging or vomiting or in the onset or duration of these symptoms. The
greatest discrepancy occurred in the eating attitudes of those patients
with borderline personality disorder. These patients were more disturbed
than nonborderline patients when it came to beliefs about eating. Borderline
patients reported a greater drive for thinness, more body dissatisfaction,
and greater difficulty in identifying inner states and feelings yet these
feelings didn't seem to be manifested in more binges or purges. Finally
the borderline patients were more likely to engage in more restrictive
dieting like fasting and crash diets.
In this experiment the researchers had some similar findings to those
in the first experiment. Those with borderline personality disorder showed
more psychiatric symptoms but the difference in the eating symptoms were
less dramatic. Borderline patients, like those studied previously, had
only slightly poorer responses in selected areas of disturbance. The researchers
found that borderline patients had more of a drive towards thinness without
displaying more binging and purging behavior than their nonborderline counterparts."Results
corroborate others linking Axis-11 comorbidity to unfavorable outcome in
the eating disorder, but suggest the character disturbance is more linked
to course of general psychiatric symptoms than it is to the course of eating
disturbances."(p. 1 49)
The researchers in the experiment had some very interesting results
that highlight the problems with this form of research and problems associated
with the other experiments. They found that the association between personality
disorders and eating disorders varied according to the diagnostic method
they used. They also found that specifically those patients with bulimia
nervosa were associated with borderline personality disorder and those
with anorexia nervosa were associated with avoidant disorder. Regardless
they had the same general conclusion that comorbidity is characterized
by chronicity and low levels of functioning and not necessarily and increase
in patterns of eating habits. The researchers do feel that their research
showed that comorbidity made eating disorders more severe due to the greater
chronicity and lower levels of functioning.
In this experiment 210 subjects with eating disorders were interviewed
to determine the prevalence of personality disorders within that group.
The researchers found the most common diagnosis to be borderline personality
disorder present in 9% of all the patients. Like the previous experiment
there were no cases of borderline personality disorder found in those patients
with anorexia. They found that overall those with personality disorders
had a longer mean duration of illness, had more comorbid Axis I disorders
and were more likely to have attempted suicide.(p.150) They also discovered
that the group with the highest rate of personality disorders, those with
bulimia nervosa had the youngest mean age of onset of their eating disorder,
the longest mean duration of illness. This suggested that a long duration
of illness may lead to a personality disorder, and personality disorders
may predispose an individual to develop an eating disorder early.(p.151).
Like several of the previous experiments the researchers in this case
also noted that subjects with personality disorders did not differ from
those without personality disorders in the amount of symptomatic changes,
in their patterns of eating , overtime. Yet for obvious reasons their psychopathology
generally remained more severe in the cases of borderline personality disorder.
There are several things that bring into question that validity of these
experiments. All of the experiments probably have their own faults but
it would take to long to go over all of them. Fortunately there are several
problems that encompass all of the experiments reviewed. The biggest problem
is in the way that patients are diagnosed with their disorders. The are
many inconsistencies within the studies due to the use of different methods
for personality disorder assessment and as well as the treatment setting
in which they are seen.(Skodol, 1993, p.415). Because of the different
methods use to measure personality disorders there can be discrepancies
between the experiments even though there goal may be relatively the same.
Unfortunately due to the number of variables involved in these experiments
it can be very difficult to brief them with out leaving out important information.
The statistics involved with these forms of experiment are long and can
be very complex, yet they can be vital to understanding the experiment.
The briefings listed above are about cover the most important information
relating directly to the question at hand.
After examining the experiments there are several key factors in the
relationship between eating disorders and personality disorders. The most
common conclusion reached by our experimenters was that borderline personality
disorder is found more often in cases of eating disorders than any other
personality disorder. Bordedine personality disorder affected those patients
with both bulimia nervosa and anorexia, in most of the experiments. Several
experiments reported few to no cases of borderline personality disorder
in patients with anorexia nervosa. Another cross experiment observation
is that personality disorders tend not to change the patterns of binging
or purging even though it may effect many of the mental aspects of eating
disorders including the feeling of needing to be thinner. One experiment
also noted that many of the borderline patients were more likely to fast
than their nonborderline counterparts. Another experiment noted that borderline
patients had a tendency to use and abuse laxatives more often than nonborderline
patients. The experimenters suggest that this may be a manifestation of
the self-inflicted physical abuse associated with people with borderline
personality disorders Overall the majority of experimenters stated two
things about the experiments in general. First of all they all, in some
way, were surprised by the outcome of the experiments. Many felt that the
difference between borderline patients and nonborderline patients with
eating disorders would be much greater. Finally many of them agreed that
more research needed to be conducted and for longer periods of time with
more consistent assessment methods.
Carroll, Julie M. et al. Specific Comorbidity Between Bulimia Nervosa
and Personality Disorders. International Journal of Eating Disorders,
Herzog, David B. et al. The Prevalence of Personality Disorders in 210
Women With Eating Disorders.Jounal of Clinical Psych8atry, Vol.
53(5), 147-152. 1992.
Johnson, Craig et al. Prevalence of Clinical Characteristics of Borderline
Patients in and Eating-Disordered Population. Journal of Clinical
Psychiatry. Vol 50(l), 9-15. (1989).
Skodol, Andrew E. et al. Comorbidity of DSM-111-R Eating Disorders and
Personality Disorders. International Journal of Eating Disorders
Vol 14(4), 403-416.(1993).
Steiger, Howard et al. Prospective Study of Outcome in Bulimics as a
Function of Axis-11 Comorbidity: Long Term Responses on Eating and Psychiatric
Symptoms. Internationgl Journal of Eating Disorders, Vol
20 (2), 149-161.(1996).
Wonderlich, Stephen A. et al. Five Year OUtcom from Eating Disorders:
Relevance of Personality Disorders. International Journal of Eating
Disorders. Vol 15(3), 233-243.(1994).
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