Stress, Hormones, and Eating
Condition: Food Addiction; How Opioid Tone Was Related to Self Reported; Drive to Eat Using a Measure of Food Addiction
MeSH terms: Behavior, Addictive; Food Addiction
Study type: Interventional
Phase: Early Phase 1

Summary: 
      The investigators will develop a measure of endogenous opioid tone that might serve as a
      biological marker for drive for palatable food. Using a 'naltrexone probe,' the investigators
      will assess whether individual response to one dose of an opioid receptor antagonist,
      naltrexone, is related to non-homeostatic eating in non-pregnant women.

      Hypothesis 1: Naltrexone Response will be related to non-homeostatic eating.

      Hypothesis 2: Response profiles to the 25 mg dose will be slightly less in magnitude than the
      50 mg dose. However, responses will be similarly related to non-homeostatic eating measures.

      Hypothesis 3: Response to naltrexone will be highly stable within individuals across time, in
      the absence of an intervention.
    

Detailed description: 
      Opioid tone may provide a way to identify people at risk of reward based eating, with more
      accuracy than self-report measures. Knowing such risk could improve treatment matching, and
      provide a biomarker to assess treatment progress. There is no direct measure of central
      opioid activity in humans, short of PET scans for opioid receptor binding. However, there is
      a promising indicator using an opioid antagonist such as naltrexone. Blocking opioid receptor
      releases the inhibitory opioidergic inputs to hypothalamic corticotropic releasing hormone
      (CRH) neurons, thus increasing CRH, and eventually cortisol in the blood. The extent of the
      cortisol rise in response to naltrexone might serve as an indicator of endogenous opioidergic
      tone. It is hypothesized that greater increases in cortisol indicate weaker endogenous opioid
      activity (by indicating a more complete opioid blockade). Salivary cortisol response to
      naltrexone may offer a relatively safe and unobtrusive way to measure endogenous opioidergic
      tone. We propose to test the reliability and validity of the naltrexone probe, taken at home,
      as a measure of endogenous opioidergic tone. In a previous study (Daubenmier et al, 2013), we
      administered a one time 50mg dose of naltrexone and examined nausea and cortisol responses.
      Results suggested that responses were higher in those who showed greater drive to eat. Here
      we examine a more direct measure of drive to eat, using the Yale Food Addiction Scale (YFAS),
      and test whether nausea and cortisol responses were associated with greater drive to eat,
      whether 50mg produced greater responses than 25 mg, and whether the responses were stable
      (highly related) when tested again one month later.
    

Intervention name(s): Naltrexone; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): 4 days, counterbalanced dosing of 25mg, 50mg, placebo, placebo.; 4 days, counterbalanced dosing of 25mg, 50mg, placebo, placebo.
Intervention MeSH terms: Naltrexone
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Other
Keywords: naltrexone; obesity; cortisol; food addiction