An fMRI Study of Opioid-related Changes in Neural Activity

Not Applicable

Completed

Brief Summary: The purpose of the study is to explore the effect of blocking opioids on affiliation-related neural activity.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Self-reported current or past diagnoses of physical or mental illness.
Score on the Patient Health Questionnaire (depressive symptoms) above a 13
Positive urine drug test (for Tetrahydrocannabinol (THC), Opiates, Cocaine, Amphetamine (AMP), and Methamphetamine (mAMP))
Positive urine pregnancy test
Use of any prescription medication, except for birth control
Use of any over-the-counter medications on the day of the fMRI session and 24 hours after the fMRI session
Self-reported problems with liver functioning, including hepatitis or liver failure
Difficulty swallowing or taking pills
BMI greater than 35 or weight greater than 400 lbs
Claustrophobia
Nonremovable metal in the body

Arm && Interventions

Group	Intervention	Description
naltrexone	Naltrexone	single 50mg dose of naltrexone
sugar pill	Placebo	single sugar pill

Primary Outcome Measures

Name	Time	Method
Bold Oxygen-level Dependent (BOLD) Activations in Prespecified ROIs	approximately one hour after taking study drug	In the MRI scanner, participants read sentences written by people they knew and people they did not know in a block design. Brain activity was measured as BOLD activity in response to reading sentences from known (vs. unknown) people using functional magnetic resonance imaging (FMRI). Based on a priori hypotheses, brain activity was masked to activity in structural regions-of-interest (ROIs) of the ventral striatum (VS) and middle-insula (MI).
Self-reported Feelings of Connection in Response to the Scanner Tasks	approximately two hours after taking study drug	feelings of social connection in response to reading sentences from known people (i.e. average of how connected, touched, warm did you feel). Feelings were reported on a scale of 1 (not at all) to 7 (very) such that higher numbers reflect greater feelings of social connection. time frame was mistakenly entered as the start of the fMRI scan, but participants reported on their feelings of social connection after the scan. Thus, the outcome measure time frame is reported as two, rather than one, hour after taking the study drug.

Secondary Outcome Measures