Neurobiology of Anorexia and Bulimia Nervosa
Neurobiology of Anorexia and Bulimia Nervosa
The purpose of this study is to investigate areas of the brain responsible for appetite
 regulation. More specifically, the investigators would like to study changes in brain
 activation, e.g., changes in blood flow and oxygen use of the brain, during two different
 states: Once when the participants are hungry, and once when the participants are not hungry.
 The aim is to find out more about the neurobiology of Anorexia and Bulimia Nervosa by
 comparing women who never had an eating disorder with women who have recovered from Anorexia
 or Bulimia Nervosa.
The main goal of this study is to explore the effects of hunger and satiety on regions in our
 brain in order to better understand the pathophysiology underlying restricted eating in
 anorexics, and overeating in women with Bulimia Nervosa. The investigators will adopt a
 paradigm that will model, in the laboratory, the naturalistic extremes of dietary intake
 practiced by women recovered from Anorexia or Bulimia Nervosa by comparing a hungry state
 (21-hour fast) to a satiated state (21-hour when fed). They may share an inability to
 precisely modulate emotionality and reward in response to salient stimuli, such as food.
 However, they may differ in terms of function of other pathways.

 The incentive motivational drive to seek and consume food is a complex process, deriving from
 interrelated psychobiological factors including food's rewarding properties, an individual's
 homeostatic needs and cognitive ability to favor alternative behaviors. In order to examine
 how these factors may contribute to dysregulated feeding behavior in women recovered from
 Anorexia or Bulimia Nervosa, the investigators will explore measures of 1) anxiety; 2)
 cognitive inhibition and dysinhibition; and 3) reward.

 Subjects will also be asked to undergo a Magnetic Resonance Imaging (MRI) scan of their head.
 This scan uses powerful magnetic fields. The magnetic fields temporarily magnetize some of
 the chemicals in our brain and this allows a scanner and a computer to take a very detailed
 picture of the structure of our brain. During the MRI, the participants will be asked to lie
 quietly inside the center of a large, doughnut shaped magnet for approximately 30 minutes.
 The participant's head will be placed in a special, helmet-like "head-holder" to help them to
 keep their head still. This part of the study will take place on the same day prior to the
 first PET scan. In this protocol, only one MRI will be done. In subjects with a questionable
 history of metallic fragments, an x-ray of the suspected body area will be performed before
 the MRI to make sure the participants have no metal fragments in their body.

 In addition to fMRI scanning there are a few other tests that will be administered. This
 includes a Pre Study Taste Test, in order to prepare them for the fMRI taste task.
 Participants will be presented five solutions of sucrose (2, 4, 8, 16 and 32 weight by
 volume) and will then be asked to rate the pleasantness of each solution using a standard
 seven-point preference scale (i.e., 1=extremely dislike; 7= extremely like). They will also
 rate perceived sweetness of each solution using a seven-point category scale (i.e., 1=absent;
 7=extreme). In addition, they will be presented variants of a tasteless solution Study
 participants will be asked to choose the solution that has the least taste and this solution
 will then be used during fMRI scanning.

 The study takes place over the span of 4 consecutive days on location at the General Clinical
 Research Center (GCRC) at the University of California in San Diego. During day 1 of the
 study, lab work would be completed in the morning and several computerized and paper and
 pencil tasks in the afternoon. Starting at noon of Day 2 and Day 3 of the study, subject
 participants will undergo two identical 21-hour cycles. In one cycle, study participants will
 refrain from eating after lunch at 12 noon until 9 a.m. the next morning and they will engage
 in fMRI studies from 9 to 10:30 a.m. In the other cycle they will be given a standardized
 diet from noon until 9 a.m. the next day and engage in fMRI studies from 9 to10:30 a.m. The
 sequence of the two cycles will be randomized across subjects. Caloric consumption will also
 be regulated. All subjects will receive exactly the same menu over the 4 days of the study.
 They will eat only when at the GCRC and only when monitored by the GCRC staff. The total
 daily energy requirement will be calculated as 30 kcal/kg body weight per day with a 53%
 carbohydrate, 32% fat, 15% protein diet. Water will be provided with the amount consumed
 recorded. Subjects will be allowed to consume their usual amounts of caffeinated beverages
 but not allowed to use artificial or natural sweeteners or cream.
Inclusion Criteria:

 -  Must have had a DSM-IV diagnosis of anorexia or bulimia nervosa

 -  The onset of their illness must have been at least 4 years prior to participating in
 this study

 -  Must have recovered for 12 months or more prior to entering the study.

 Exclusion Criteria:

 -  Met diagnosis of alcohol or drug abuse or dependence in the 3 months prior to the
 study.

 -  Current diagnosis of a severe major affective or anxiety disorder or presence of other
 psychopathology that might interfere with ability to participate in the study.

 -  Organic brain syndromes, dementia, psychotic disorders or mental retardation

 -  Neurological or medical disorders

 -  Use of psychoactive medication in the 3 months prior to the study.

 -  Pregnancy or lactation, lack of effective birth control during 15 days before the
 scans.