Recruiting
Early Phase 1

Naltrexone

Sponsor:

San Diego State University

Code:

NCT05007561

Conditions

Naltrexone

Placebo

Eligibility Criteria

Sex: All

Age: 18 - 25

Healthy Volunteers: Accepted

Interventions

Naltrexone Hydrochloride

Placebo

Study Details

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.

Conditions

Naltrexone

Placebo

Study ID

NCT05007561

Start date

Nov 16, 2021

Status verified date

Apr, 2026

Completion date

Jul, 2027

Anticipated

Primary completion date

Apr, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 25

Healthy Volunteers: Accepted

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

Study Design

Enrollment

210 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Naltrexone

50mg naltrexone HCL once daily for seven days by mouth

placebo comparator: placebo

sugar pill once daily for seven days by mouth

Interventions

Naltrexone Hydrochloride

oral naltrexone

Placebo

oral sugar pill

Primary outcome measure

  • Daily feelings of social connection via ecological momentary assessment [ Time Frame: post-treatment, change across 7 days ]
  • Bold Oxygen-level Dependent (BOLD) Activations in Prespecified ROIs [ Time Frame: Day 7, approximately 60 mins after taking study drug ]
  • feelings in response to neuroimaging tasks [ Time Frame: Day 7, approximately 150 minutes after taking study drug ]

Central Contacts and Locations

Central contacts

Tristen Inagaki, PhD

6195941058tinagaki@sdsu.edu

Locations

San Diego State University

Recruiting

San Diego, California, United States, 92120

More Information

Sponsor

San Diego State University

Last update posted

Apr 13, 2026

Last verified

Apr, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by San Diego State University on 2026-04-13.