FearEarly Phase 1SSONCT04166071
Opioids and Social Support Enhanced Extinction Effects
A Early Phase 1 study testing Naltrexone in people with Fear, run by University of California, Los Angeles at 2 sites in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Fear
- What is being tested?
- Naltrexone
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 2 sitesUnited States
- Study dates
- 13 Dec 2021to 1 Dec 2026
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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)
Who cannot join
- 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
Show all 9Show fewer
- difficulty or discomfort swallowing pills
- history of substance abuse or addiction (especially alcohol or opiate abuse)
- Other exclusion criteria may apply.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites
UCLA Department of Psychology, 5514 Pritzker Hall
Los Angeles, California, 90095-1563
UCLA
Los Angeles, California, 90095
About this study
Official title: Revisiting Safety Signals: Examining a Separate Safety Mechanism for Social Support Figures
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.
- Conditions
- Fear
- Being tested
- Naltrexone, Placebo
- Keywords
- social support, fear extinction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NaltrexoneDrug
Half of the participants will be randomly assigned to take one dose of naltrexone (50mg, capsule form) during the experimental session
PlaceboDrug
Half of the participants will be randomly assigned to take a placebo capsule during the experimental session
| Study group | Role | What they receive |
|---|---|---|
| Naltrexone | Active comparator | Not described Receives: Drug: Naltrexone |
| Placebo | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fear Response directly post-extinction
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).
Measured: Directly following a fear extinction procedure (during the experiment session).
Fear Response 24-hours post-extinction
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).
Measured: 24 hours following the completion of the fear extinction procedure (during a follow-up fear reinstatement session).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Nov 2019
- Study start13 Dec 2021
- Primary completion1 Dec 2026 (estimated)
- Study completion1 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for FearStudies of the same condition, open and under way.
- More trials run by University of California, Los AngelesThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Los Angeles
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Mental Health (NIMH)
- Responsible party
- Principal investigator, Naomi Eisenberger, University of California, Los Angeles
- Investigators
- Naomi Eisenberger, Ph.D., Principal investigator, University of California, Los Angeles
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04166071
- Sponsor's protocol ID
- SSO
- Acronym
- SSO
- Status last verified
- Oct 2026
- First submitted
- 5 Nov 2019
- Last updated
- 15 Oct 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Revisiting Safety Signals: Examining a Separate Safety Mechanism for Social Support Figures
- ClinicalTrials.gov ID
- NCT04166071
- Acronym / sponsor ID
- SSO / SSO
- Conditions
- Fear
- Keywords
- social support, fear extinction
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- University of California, Los AngelesUniversity, hospital or other
- Collaborators
- National Institute of Mental Health (NIMH)
- Study start
- 13 Dec 2021 (actual)
- Primary completion
- 1 Dec 2026 (estimated)
- Study completion
- 1 Dec 2026 (estimated)
- First posted
- 18 Nov 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Naltrexone | Active comparator | Drug: Naltrexone |
| Placebo | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- 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)
Key exclusion criteria (9 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| NaltrexoneHalf of the participants will be randomly assigned to take one dose of naltrexone (50mg, capsule form) during the experimental session | Drug | Naltrexone |
| PlaceboHalf of the participants will be randomly assigned to take a placebo capsule during the experimental session | Drug | Placebo |
Primary outcome
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).
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).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Oct 2026.
Related trials for Fear
Recruiting
Distraction Cards Versus Emotion-Regulation Toy Squeezing During Intramuscular Vaccination in Preschool Children
Procedural Pain, Pain-related Fear
Active, not recruiting
A Nurse-Led Intervention for Fear of Progression in Advanced Cancer
Advanced Lung Carcinoma, Metastatic Malignant Female Reproductive System Neoplasm
Recruiting
Changes in Person-reported Outcomes and Behavior Using the Accu-Chek SmartGuide CGM and Predict App
Diabetes (DM), Diabetes Mellitus
Not yet recruiting
Multicomponent Exercise and Pain Science Education for Fall Prevention in Older Adults With Chronic Musculoskeletal Pain (MovePainFall)
Chronic Pain, Musculoskeletal Pain
Active, not recruiting
Uncertainty and Firearms: Obtaining Secure Storage
Anxiety
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Naomi Eisenberger, Ph.D. principal investigator
University of California, Los Angeles
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Naltrexone in people with Fear, run by University of California, Los Angeles at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fear Response directly post-extinction (time frame: Directly following a fear extinction procedure (during the experiment session).). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2026.