The Impact of Methadone Maintenance Therapy on Food Reward Processing in Opioid Dependence
Condition: Opioid Dependence; Obesity
MeSH terms: Opioid-Related Disorders
Study type: Interventional

Summary: 
      Methadone maintenance therapy (MMT) has shown clear efficacy for relieving opioid withdrawal
      symptoms and reducing the morbidity and mortality of opioid dependence. A notable phenomenon
      associated with MMT is increased food intake, enhanced sweet preferences, and weight gain.
      The underlying neural mechanisms for opioid-related overconsumption are not well understood
      but are thought to arise from role in 1) increasing the palatability and hedonic aspects of
      food and 2) diminishing satiety signaling systems. In the proposed project, the investigators
      will examine methadone's potential role in opioid-related overconsumption of food. The
      investigators propose to examine eating behavior, sucrose preferences, and an event-related
      potential (ERP) component that is induced by appetitive motivation for highly rewarding foods
      in patients with a history of opioid dependence receiving methadone maintenance therapy
      (O+MMT) and not receiving opioid agonist therapy (O-MMT). A matched sample of obese and
      overweight adults without history of opioid use (HOC) will also be examined.
    

Detailed description: 
      Methadone maintenance therapy (MMT) has shown clear efficacy for relieving opioid withdrawal
      symptoms and reducing the morbidity and mortality of opioid dependence. A notable phenomenon
      associated with MMT is increased food intake, enhanced sweet preferences, and weight gain.
      The underlying neural mechanisms for opioid-related overconsumption are not well understood
      but are thought to arise from role in 1) increasing the palatability and hedonic aspects of
      food and 2) diminishing satiety signaling systems. In the proposed project, the investigators
      will examine methadone's potential role in opioid-related overconsumption of food. The
      investigators propose to examine eating behavior, sucrose preferences, and an event-related
      potential (ERP) component that is induced by appetitive motivation for highly rewarding foods
      in patients with a history of opioid dependence receiving methadone maintenance therapy
      (O+MMT) and not receiving opioid agonist therapy (O-MMT). A matched sample of obese and
      overweight adults without history of opioid use (HOC) will also be examined. Specifically,
      group differences in food intake and eating behaviors in the O+MMT group relative to
      individuals in the O-MMT and HOC group will be examined. Individuals will complete 24-hour
      dietary food recalls and inventories to characterize eating behavior and food addiction.
      Participants will complete psychophysical measures of chemosensory functioning of sucrose
      preference and pleasantness and identification ratings for odors varying in participants'
      hedonic characteristics. Individuals will also complete validated computer tasks to assess
      food preferences. Differences in cortical ERPs for high-reward food relative to low-reward
      food and non-food items will be examined. Event-related potentials will be recorded as
      participants view photos of rewarding and non-rewarding food items, as well as non-food
      items. ERP components that index sustained attentional engagement will be measured and
      compared.
    

Intervention name(s): Sniffin' Sticks Odor Identification and Hedonic Scale; Sucrose Taste Preference Assessment; Food Preferences Task; Progressive Ratio (PR) Task; Clinical Electrophysiology; Standardized Meal and Hunger and Satiety Ratings
Intervention type(s): Behavioral; Behavioral; Behavioral; Behavioral; Procedure; Dietary Supplement
Intervention description(s): This task measures odor identification accuracy and perceived pleasantness of odors.; This task measures participant ratings of sucrose preference.; Participants rate images of various food stimuli. Variables derived include relative preferences and reaction time (in milliseconds).; In the PR task, the subject is required to make an increasing number of operant responses for each successive reward; To examine motivated attention in response to food stimuli, brain electrophysiology via event related potentials (ERPs) will be assessed while participants view and rate images of food and non-food items.; Participants will receive a standardized meal and complete hunger and satiety ratings.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Intervention model description: The investigators will recruit thirty individuals meeting criteria for opioid dependence of which 15 will be receiving MMT (O+MMT) and 15 will be on no opioid agonist therapy (O-MMT). The investigators will attempt to match the O-MMT group to the O+MMT group for clinical characteristics and smoking burden. Fifteen obese/overweight adults without history of opioid/substance use will be matched to the patient groups for age, gender, education, smoking and BMI.
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: methadone; opioid dependence; obesity; food reward; olfactory