Naltrexone, Placebo
Conditions
Brief summary
The study is a randomized, placebo-controlled design with the opioid antagonist, oral naltrexone. Following random assignment, participants will take 50mg of naltrexone or placebo once a day for 7 days. On days 1 - 7, participants complete reports of their feelings of social connection and mood in order to assess more naturalistic feelings in response to opportunities for social connection outside of the laboratory setting. Additionally, at the end of each day, they complete a physical symptoms questionnaire. On the 7th day, participants will come to the SDSU MRI scanning facility to complete tasks designed to elicit feelings of social connection in the fMRI scanner. After the scan, feelings in response to the scanner tasks will be collected.
Interventions
oral naltrexone
DRUGPlacebo
oral sugar pill
Sponsors
National Institute on Drug Abuse (NIDA)
San Diego State University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 25 Years
Healthy volunteers
Yes
Inclusion criteria
* good health * English fluency * willing to provide contact information for 4-6 close others * willing to provide digital photographs of 2 close others * own a smartphone
Exclusion criteria
* presence of medical devices, implants, or other metal objects in or on the body that cannot be removed * tattooed eyeliner * a body habitus prohibiting MRI scanning * claustrophobia * self-reported chronic mental or physical illness * current and regular use of prescription medication * previous history of having difficulty taking pills * current use of opioid analgesics * depressive symptoms above a 9 on Patient Health Questionnaire * excessive alcohol use * positive urine drug test * body mass index (BMI) greater than 35 * pregnancy or plans to become pregnant in next 6 months * positive urine pregnancy test
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Daily feelings of social connection via ecological momentary assessment | post-treatment, change across 7 days | State feelings of social connection outside of the lab |
| Bold Oxygen-level Dependent (BOLD) Activations in Prespecified ROIs | Day 7, approximately 60 mins after taking study drug | In the MRI scanner, participants read sentences written by people they know and people they do not know in a block design. In a second task they view images of people they know, those they do not know, and other emotional images. Brain activity will be measured as BOLD activity in response to stimuli from known (vs. unknown) people using functional magnetic resonance imaging (FMRI). Based on a priori hypotheses, brain activity will be masked to activity in structural regions-of- interest (ROIs) of the ventral striatum (VS), middle-insula (MI), anterior cingulate cortex (ACC) and ventromedial prefrontal cortex (VMPFC). |
| feelings in response to neuroimaging tasks | Day 7, approximately 150 minutes after taking study drug | Feelings of social connection and general positive affect in response to the neuroimaging tasks will be reported on a scale of 1 (not at all) to 7 (very) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| physical symptoms via daily diary | end of day on days 1-7 | Physical symptoms previously associated with naltrexone will be assessed as well as the subjective experience of the symptoms. |
Countries
United States
Contacts
Primary ContactTristen Inagaki, PhD
Outcome results
None listed