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Enrolling by Invitation

NCT Number: NCT04166071

Opioids and Social Support Enhanced Extinction Effects

University of California, Los Angeles researchers will recruit healthy participants (age 18-35) to participate in a study examining whether the administration of naltrexone, an opioid antagonist, eliminates the ability of social support figure reminders to enhance fear extinction--a process during which a threatening cue is learned to not predict a negative or threatening outcome (i.e., electric shock) by being repeatedly presented in the absence of that outcome.

After undergoing an email screening, a telephone screening, an in lab screening, and a health screening, 60 participants will be enrolled in the study. During the experiment, 30 participants will be administered naltrexone and 30 participants will be administered placebo (both participants and experimenters will be blind to condition) before undergoing a fear extinction procedure in which threatening cues--cues that predict electric shock--will be paired with either an image of a social support figure (provided by participants) or a second threatening cue. These pairings will be presented repeatedly in the absence of shock in order for fear extinction to occur. Participants will return for a follow-up test to determine if fear extinction was successful.

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Key information

Conditions

Fear

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

UCLA, Los Angeles, California, United States

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Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • healthy adults 18 and 35
  • fluent in English
  • no history of mental illness (including anxiety, depression, phobia, or any other mental health related disorder diagnosed by a mental health professional)

Exclusion criteria

  • pregnant or planning to become pregnant during the experiment period
  • presence of chronic mental illness (as determined by the report of a past diagnosis of mental illness by a physician or psychologist and/or the prescription of medication related to mental health disorder; including anxiety, depression, phobia, or any other diagnosed psychological disorder)
  • chronic physical illness (as determined by past diagnosis and/or treatment by a physician)
  • history of liver disease or abnormal liver function
  • current and regular use of prescription medications related to mental health disorders or liver function
  • previous history of fainting during blood draws
  • difficulty or discomfort swallowing pills
  • history of substance abuse or addiction (especially alcohol or opiate abuse)

Other exclusion criteria may apply.

Treatment and study plan

Naltrexone

Drug

Half of the participants will be randomly assigned to take one dose of naltrexone (50mg, capsule form) during the experimental session

Placebo

Drug

Half of the participants will be randomly assigned to take a placebo capsule during the experimental session

Primary outcomes

  1. Fear Response directly post-extinction

    Time frame: Directly following a fear extinction procedure (during the experiment session).

    presence of fear response as indicated by significantly higher galvanic skin response (GSR: an index of peripheral stress responding) to a previously learned fearful image (CS+) compared to a baseline comparator (CS-: never learned to be fearful).

  2. Fear Response 24-hours post-extinction

    Time frame: 24 hours following the completion of the fear extinction procedure (during a follow-up fear reinstatement session).

    presence of fear response as indicated by significantly higher galvanic skin response (GSR: an index of peripheral stress responding) to a previously learned fearful image (CS+) compared to a baseline comparator (CS-: never learned to be fearful).

Sponsors and collaborators

Lead sponsor

University of California, Los Angeles

Other

Collaborators

  • National Institute of Mental Health (NIMH)

Registry information

Official study title

Revisiting Safety Signals: Examining a Separate Safety Mechanism for Social Support Figures

Acronym: SSO

Important dates

Study start
2021
Primary completion
2026
Study completion
2026
First posted
Nov 18, 2019
Registry last updated
Oct 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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