Changes in Dopamine Levels Before and After Weight Restoration in People With Anorexia Nervosa
Condition: Eating Disorders
MeSH terms: Anorexia; Feeding and Eating Disorders; Anorexia Nervosa
Study type: Observational

Summary: 
      This study will use positron emission tomography imaging to investigate changes in dopamine
      systems in people with anorexia nervosa before and after weight restoration.
    

Detailed description: 
      Anorexia nervosa (AN) is a disordered eating disease characterized by a persistent pursuit of
      thinness, intense fear of weight gain, distorted body image, and obsessive eating habits.
      People with AN are at high risk for certain health problems, such as depression,
      osteoporosis, substance abuse, and cardiovascular and neurological complications. Current
      treatments for AN include different forms of psychotherapy and medications, but the success
      of these treatments is highly variable among people with AN. A better pathophysiologic
      understanding of AN is needed in order to develop novel therapeutic strategies for preventing
      and treating the disorder. Current research is targeting dopamine (DA), a neurotransmitter
      that is released in response to pleasurable stimuli, such as food and drugs. Animal studies
      have found that chronic food restriction may alter functioning of the DA system by reducing
      DA response to food and drug stimuli. A better understanding of the effects of disordered
      eating on the DA systems of people with AN may provide insight into the development of new
      and improved treatments for people with AN. This study will use positron emission tomography
      (PET) imaging to investigate changes in DA systems in people with AN before and after both
      weight restoration and administration of methylphenidate, a psychostimulant medication. The
      study will also use PET imaging to compare DA systems of people with AN with DA systems of
      people who are healthy.

      This study will involve both healthy participants and participants with AN. Study
      participation for healthy participants will include two PET scans and one magnetic resonance
      imaging (MRI) scan, which, if the participants prefer, can all be completed in one study
      visit. Study participation for participants with AN will include three PET and two MRI scans.
      The first PET and MRI scans will be performed upon entry into the hospital as an inpatient.
      The remaining scans will be conducted 2 to 4 weeks after participants have accomplished
      weight restoration.

      Including preparation, each MRI study will last about 45 minutes and each PET study will last
      about 3 hours. For each MRI study, participants will be asked to lie on their backs for 15
      minutes in the MRI scanner. For each PET study, participants will first be injected with a
      dose of [11C]raclopride, a radioactive drug used in brain imaging, and will then lie on their
      backs for 30 minutes in the PET scanner.

      One hour before the second PET scan for healthy participants and the third PET scan for
      participants with AN, participants will receive an oral dose of methylphenidate. During these
      scans, participants will also undergo blood pressure monitoring and an electrocardiogram
      (EKG). Once participants no longer feel the effects of the methylphenidate and their vital
      signs have returned to normal, they will be discharged from the medical center and study
      participation will be complete.
    

Intervention name(s): Positron Emission Tomography (PET) using [11C]raclopride; Methylphenidate; Magnetic Resonance Imaging (MRI) scan
Intervention type(s): Radiation; Drug; Procedure
Intervention description(s): Participants with AN will undergo three PET scans at two separate time points. The first scan will occur when participants are underweight (but not less than 75% ideal body weight), and the second and third scans will occur 2 to 4 weeks after participants have accomplished weight restoration. Healthy participants will have two PET scans at a single timepoint.; The second PET scan for healthy participants and third PET scan for participants with AN will be performed after administration of 60 mg of methylphenidate, a psychostimulant that allows for accumulation of dopamine (DA) extraneuronally.; Participants with AN will undergo two MRI scans, and healthy participants will undergo one MRI scan. The scans will be conducted in conjunction with the PET scans.
Intervention MeSH terms: Raclopride; Methylphenidate
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        The study population will include people with anorexia nervosa seeking inpatient treatment
        or already receiving inpatient treatment and people who will act as healthy control
        participants.
      
Keywords: Anorexia Nervosa; PET Imaging; Dopamine