Understanding How Opioids Affect the Experiential and Neural Signatures of Social Experiences

Early Phase 1RecruitingNCT05007561

San Diego State University210 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

210

Conditions

Naltrexone Placebo

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 25 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Daily feelings of social connection via ecological momentary assessment

State feelings of social connection outside of the lab

Time frame: post-treatment, change across 7 days

Bold Oxygen-level Dependent (BOLD) Activations in Prespecified ROIs

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).

Time frame: Day 7, approximately 60 mins after taking study drug

feelings in response to neuroimaging tasks

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)

Time frame: Day 7, approximately 150 minutes after taking study drug

Secondary Outcomes

physical symptoms via daily diary

Physical symptoms previously associated with naltrexone will be assessed as well as the subjective experience of the symptoms.

Time frame: end of day on days 1-7