Posttraumatic Stress DisorderPhase 1NCT04080427
Effects of Delta9-tetrahydrocannabinol (THC) on Retention of Memory for Fear Extinction Learning in PTSD: R33 Study
A Phase 1 study testing Dronabinol 7.5 milligram oral capsule in people with Posttraumatic Stress Disorder, run by Wayne State University at 1 site in United States.
Trial summary
The goal of this study is to look at how a type of drug called cannabinoids are related to the processing of fear signals, the experience of emotions and fear, and the pattern of activity in the brain that is involved in these processes and how this relates to the treatment of post-traumatic stress disorder (PTSD). Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Posttraumatic Stress Disorder
- What is being tested?
- Dronabinol 7.5 milligram oral capsule
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 102 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Apr 2021to 31 May 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Between ages 18-60
- Willing and able to consent to study
- Generally medically and neurologically healthy (including no evidence of intellectual disability or serious cognitive impairment that would interfere with task performance)
- Exposure to Criterion A stressor defined by CAPS-5 and identified by Life Events Checklist-5 (LEC-5)
- Significant PTSD severity as indicated by CAPS-5 diagnosis and/or score >= 25 of at least one month prior to study entry, PTSD is patient's primary concern
Who cannot join
- Positive urine pregnancy test prior to fMRI, self-reported current pregnancy during screening, or planning pregnancy
- Currently breastfeeding/ lactating
- MRI contraindications (e.g., ferrous metal in head/body)
- Pervasive development disorder history
- Traumatic brain injury (TBI) with current cognitive impairment related to TBI
- Risk of harm to self or others that requires immediate intervention
Show all 14Show fewer
- Presence of contraindications, current or past allergic or adverse reaction, or known sensitivity to cannabinoid-like substances (dronabinol/marijuana/cannabis/THC, cannabinoid oil, sesame oil, gelatin, glycerin, and titanium dioxide)
- Lack of fluency in English
- Inability to tolerate small, enclosed spaces without anxiety (e.g. claustrophobia
- Exclusively left-handed (score of -100 on Handedness Questionnaire)
- Current or past diagnosis of bipolar, schizophrenia spectrum, psychotic and related disorders
- Current severe alcohol or substance use
- Comorbid mood or anxiety disorder that is primary to PTSD
- Concomitant treatment with medication taken daily that has level 1 evidence indicating severe drug-drug interactions with dronabinol
Trial locations and contacts
1 site in 1 country.
United States1 site
Eugene Applebaum College of Pharmacy and Health Sciences
Detroit, Michigan, 48201
About this study
Official title: Effects of THC on Retention of Memory for Fear Extinction Learning in PTSD: R33 Study
The goal of this study is to look at how a type of drug called cannabinoids are related to the processing of fear signals, the experience of emotions and fear, and the pattern of activity in the brain that is involved in these processes and how this relates to the treatment of post-traumatic stress disorder (PTSD). PTSD is an anxiety disorder that occurs after experiencing a traumatic event(s) and is characterized by unwanted memories of the trauma(s) through flashbacks or nightmares, avoidance of situations that remind the person of the event, difficulty experiencing emotions, loss of interest in activities the person used to enjoy, and increased arousal, such as difficulty falling asleep or staying asleep, anger and hypervigilance. The information gained from this study could lead to the development of new treatments for persons who suffer from anxiety or fear-based disorders.
Read the detailed description
The total time commitment estimated per participant 18 study visits. This is broken down below:
Visit 1: Questionnaires, Screening, and Orientation: During this visit the potential participant will learn about the study procedures, sign the informed consent documents, and fill out a packet of forms that ask about his or her race and ethnic background, use of drugs and alcohol and physical and mental health.
Visit 2: Pre-Treatment Behavioral Tests and and Magnetic Resonance (MR) Scan: During this visit the participant will complete several computer tasks, and the study staff will be measuring reaction time and psychophysiological measures.The tasks that the participant will perform will show three different images and an aversive stimulus (e.g. loud burst of noise or animated snake) may follow one image most of the time, while the other images may never be followed by the aversive cue. The participant will need to try to predict whether the aversive cue will occur or not based on which image is shown and will be asked to repeatedly rate on a scale how likely it is that he or she thinks an aversive cue will occur after each image. Lastly, during the session the participant will also be asked to report his or her level of anxiety on a scale from 0 to 100.
Visit 3: Pre-Treatment Behavioral Tests and MR Scan: This visit will be very similar to Visit 2. Participants will participate in the same type of task inside the MR scanner, while the study staff measures reaction time and psychophysiological responding and brain activation. Participants will view the same images he or she did previously, and may experience the same aversive stimulus as during Visit 2. Participants will again be asked to rate how much they expect to experience the aversive stimulus after each image and will also be asked to report their level of anxiety on a scale from 0 to 100.
Visits 4 \& 5: Prolonged Exposure (PE) Sessions 1 \& 2: These sessions will consist of psychoeducation that includes discussion or reactions to trauma , treatment rationale, breathing retraining, and review of SUDS to assess level of distress from 0 to 100 (100=extreme anxiety/distress) when facing fears. One session occurs weekly across 2 weeks.
Visits 6-14: PE Sessions 3-11: These sessions will consist of repeated exposures to trauma memories (imaginal exposure) and avoided situations (in vivo exposure). As is standard, patients will also practice exposures (e.g., listen to tapes of imaginal exposure, carry out in vivo exposure) outside of PE sessions as "homework". At exposure-focused sessions (Sessions 3-11) either THC or PBO will be administered just before the session. One session occurs weekly across 8 weeks.
Visit 15: PE Session 12 [Post-treatment Assessment]: This session will include a review of therapeutic gains/relapse prevention/assessments.
Visit 16: Post-Treatment Behavioral Tests and MR Scan: This visit will be very similar to Visit 2. Participants will participate in the same type of task inside the MR scanner, while the study staff measures reaction time and psychophysiological responding and brain activation. Participants will view the same images he or she did previously, and may experience the same aversive stimulus as during Visit 2. Participants will again be asked to rate how much they expect to experience the aversive stimulus after each image and will also be asked to report their level of anxiety on a scale from 0 to 100.
Visit 17: Post-Treatment Behavioral Tests and MR Scan: This visit will be very similar to Visit 3. Participants will participate in the same type of task inside the MR scanner, while the study staff measures reaction time and psychophysiological responding and brain activation. Participants will view the same images he or she did previously, and may experience the same aversive stimulus as during Visit 3. Participants will again be asked to rate how much they expect to experience the aversive stimulus after each image and will also be asked to report their level of anxiety on a scale from 0 to 100.
Visit 18: 3-Month Follow-Up Treatment Assessment: This session is similar to Visit 15 and will include review of therapeutic gains/relapse prevention/assessments.
- Conditions
- Posttraumatic Stress Disorder
- Being tested
- Placebo capsule, Dronabinol 7.5 milligram oral capsule
- Medical subject headings
- Stress Disorders, Post-Traumatic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Placebo capsuleDrug
Also called sugar pill
Placebo is administered just prior to weekly exposure sessions by the oral route and contains only dextrose in opaque capsules.
Dronabinol 7.5 milligram oral capsuleDrug
Also called Marinol
Dronabinol (7.5mg) is administered just prior to weekly exposure sessions by the oral route and is placed in an opaque capsule with dextrose filler.
| Study group | Role | What they receive |
|---|---|---|
| Placebo capsule | Placebo comparator | In a randomized, double-blind, placebo-controlled, between-subjects design, the investigators will administer a single oral dose of dronabinol (7.5mg) or placebo (PBO) approximately two hours prior to each weekly exposure session (up to 9 sessions) in a standard prolonged exposure treatment protocol comprising 12 session overall.
Half of the participants will receive 7.5mg dronabinol (n=50) and the other half of the participants will receive placebo (n=50). Receives: Drug: Placebo capsule |
| Dronabinol 7.5 milligram oral capsule | Experimental | In a randomized, double-blind, placebo-controlled, between-subjects design, the investigators will administer a single oral dose of dronabinol (7.5mg) or placebo (PBO) approximately two hours prior to each weekly exposure session (up to 9 sessions) in a standard prolonged exposure treatment protocol comprising 12 session overall.
Half of the participants will receive 7.5mg dronabinol (n=50) and the other half of the participants will receive placebo (n=50). Receives: Drug: Dronabinol 7.5 milligram oral capsule |
What is being measured
The primary outcome is the main question the study is designed to answer.
Brain Measures
functional magnetic resonance imaging (fMRI) blood oxygen level-dependent (BOLD) percent signal change within region of interests [amygdala; ventromedial prefrontal cortex; hippocampus]
Measured: Through study completion, an average of 3 months.
Psychophysiology
Skin conductance response (SCR): change in SCR [peak amplitude from 0.5-4.5 sec following stimulus presentation minus average 2 second baseline prior to stimulus presentation].
Measured: Through study completion, an average of 3 months.
Expectancy Ratings
To assess the change in expected likelihood that an aversive cue (e.g. noise burst or shock) will occur or not based on while slide was shown, participants will repeatedly rate their expectancy of the aversive cue using a button box on a scale from 1 to 3 [1 = certain that the aversive cue will be presented; 2 = certain that the aversive cue will not be presented; 3 = uncertain whether the aversive cue will be presented].
Measured: Through study completion, an average of 3 months.
PTSD Checklist (PCL-5)
To track PTSD symptom change for each participant. The PCL-5 is a 20-item questionnaire. The self-report rating scale is 0-4 for each symptom: "Not at all," "A little bit," Moderately," "Quite a bit," and "Extremely", respectively. A total symptom severity score (range - 0-80) can be obtained by summing the scores for each of the 20 items.
Measured: Through study completion, an average of 3 months.
Clinician Administered PTSD Scale for Diagnostic and Statistical Manual (DSM)-5 (CAPS-5)
To track PTSD symptom change for each participant. The CAPS is the gold standard in PTSD assessment. The CAPS is a 30-item structured interview. In addition to assessing the 20 DSM-5 PTSD symptoms, questions target the onset and duration of symptoms, subjective distress, impact of symptoms on social and occupational functioning, improvement in symptoms since a previous CAPS administration, overall response validity, overall PTSD severity, and specifications for the dissociative subtype. The assessor combines information about frequency and intensity of an item into a single severity rating. Total symptom severity score is calculated by summing severity scores for the 20 DSM-5 PTSD symptoms. The five-point CAPS-5 symptom severity rating scale is used for all symptoms (0, Absent; 1, mild; 2, Moderate/threshold; 3, Severe/markedly elevated; 4, Extreme/incapacitating). Total CAPS-5 symptom severity scores range from 0-80, with higher scores indicating worse PTSD symptom severity.
Measured: Through study completion, an average of 3 months.
Subjective Units of Distress Scale (SUDS)
To assess the change in level of distress from 0 to 100 when facing fears. The higher the number on the scale the more severe the level of distress experienced.
Measured: Through study completion, an average of 3 months.
Secondary outcomes (7)
Visual Analogue Scale of Mood (VAS)
Subjective ratings of mood and drug effects on a 0-100. Higher numbers on the scale reflect stronger experiences of different mood and drug effects. Each item is scored individually. There is no overall score.
Measured: Through study completion, an average of 3 months.
Drug Effects Questionnaire (DEQ)
Subjective ratings of drug effects on from 1-5 on the following scales: "Feel", "High", and "Like".
Measured: Through study completion, an average of 3 months.
Addiction Research Center Inventory (ARCI)
A standardized questionnaire of 53 statements for assessing subjective effects of psychoactive drugs. Used to differentiate drug effects from placebo. Participants rate "true" if the statement applies to them or "false" if it does not apply. Specific statements are related to a particular drug class and for that drug class all "true" responses are summed for a total score in that drug class. Higher scores means higher subjective drug effects for particular drug classes. The scales are the Morphine-Benzedrine (score range: 0-16; drug-induced euphoria), Amphetamine (score range: 0-11; specific for dose-related effects of d-amphetamine), Benzedrine (score range: 0-13; an amphetamine scale relating to intellectual efficiency and energy); Pentobarbital-Chlorpromazine (score range: 0-15; sedation); Lysergic Acid (score range: 0-13; dysphoria and somatic symptoms); and Marijuana (score range: 0-12; marijuana's effects).
Measured: Through study completion, an average of 3 months.
State-Trait Anxiety Inventory (STAI)
Measures of state and trait anxiety. The STAI has 20 items for assessing trait anxiety and 20 for state anxiety. State anxiety items include: "I am tense; I am worried" and "I feel calm; I feel secure." Trait anxiety items include: "I worry too much over something that really doesn't matter" and "I am content; I am a steady person." All items are rated on a 4-point scale (e.g., from "Almost Never" to "Almost Always"). The numerical ratings for each of the 20 items assessing trait anxiety are summed for a total trait anxiety score. The numerical ratings for each of the 20 items assessing state anxiety are summed for a total state anxiety score. Scores on the trait and state anxiety scales of the STAI can range from 20-80. STAI scores are commonly classified as "no or low anxiety" (scores 20-37), "moderate anxiety" (scores 38-44), and "high anxiety" (scores 45-80).
Measured: Through study completion, an average of 3 months.
End of Session Questionnaire (ESQ)
Includes 5 questions total. The first two question ask the participant to select one of several statements that best describes the effect of the capsule they took during that visit. The second question asks the participant to guess what they thought they received in the capsule and how confident they are. The third question asks the participant to rate how much the liked or disliked the effects of the capsule overall on a scale from -5 to 5, with -5 being "disliked a lot", 0 being "neutral", and 5 being "liked a lot". The fourth question asks participants to check "yes" or "no" if they would take the capsule again. Finally, the last question is a free text response asking the participant if they experienced any unusual reactions or if they have any comments or observations that may be relevant to the study.
Measured: Through study completion, an average of 3 months.
Heart Rate
Heart rate
Measured: Through study completion, an average of 3 months.
Blood Pressure
Systolic and diastolic blood pressure will be assessed.
Measured: Through study completion, an average of 3 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Sep 2019
- Study start15 Apr 2021
- Primary completion31 May 2025
- Study completion31 May 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Posttraumatic Stress DisorderStudies of the same condition, open and under way.
- 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
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 102 participants (actual)
Sponsor and investigators
- Lead sponsor
- Wayne State University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Mental Health (NIMH)
- Responsible party
- Principal investigator, Christine Rabinak, PhD, Wayne State University
- Investigators
- Christine A Rabinak, PhD, Principal investigator, Wayne State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04080427
- Sponsor's protocol ID
- R33MH111935
- Other IDs
- R61MH111935
- Status last verified
- Jul 2025
- First submitted
- 30 Aug 2019
- Last updated
- 11 Jul 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Rabinak CA, Kilgore PE, Lumley MA, Rauch SAM. Randomized trial of delta-9-tetrahydrocannabinol (THC) versus placebo to augment the effects of prolonged exposure therapy on fear extinction learning in post-traumatic stress disorder: Study rationale and protocol. Contemp Clin Trials. 2026 Jan;160:108148. doi: 10.1016/j.cct.2025.108148. Epub 2025 Nov 19.
PubMed 41270825
Study at a glance
From the registry record, last updated by the sponsor on 11 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of THC on Retention of Memory for Fear Extinction Learning in PTSD: R33 Study
- ClinicalTrials.gov ID
- NCT04080427
- Acronym / sponsor ID
- R33MH111935
- Conditions
- Posttraumatic Stress Disorder
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 102 participants (actual)
- Lead sponsor
- Wayne State UniversityUniversity, hospital or other
- Collaborators
- National Institute of Mental Health (NIMH)
- Study start
- 15 Apr 2021 (actual)
- Primary completion
- 31 May 2025 (actual)
- Study completion
- 31 May 2025 (actual)
- First posted
- 6 Sep 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.
The goal of this study is to look at how a type of drug called cannabinoids are related to the processing of fear signals, the experience of emotions and fear, and the pattern of activity in the brain that is involved in these processes and how this relates to the treatment of post-traumatic stress disorder (PTSD). PTSD is an anxiety disorder that occurs after experiencing a traumatic event(s) and is characterized by unwanted memories of the trauma(s) through flashbacks or nightmares, avoidance of situations that remind the person of the event, difficulty experiencing emotions, loss of interest in activities the person used to enjoy, and increased arousal, such as difficulty falling asleep or staying asleep, anger and hypervigilance. The information gained from this study could lead to the development of new treatments for persons who suffer from anxiety or fear-based disorders.
Detailed description
The total time commitment estimated per participant 18 study visits. This is broken down below:
Visit 1: Questionnaires, Screening, and Orientation: During this visit the potential participant will learn about the study procedures, sign the informed consent documents, and fill out a packet of forms that ask about his or her race and ethnic background, use of drugs and alcohol and physical and mental health.
Visit 2: Pre-Treatment Behavioral Tests and and Magnetic Resonance (MR) Scan: During this visit the participant will complete several computer tasks, and the study staff will be measuring reaction time and psychophysiological measures.The tasks that the participant will perform will show three different images and an aversive stimulus (e.g. loud burst of noise or animated snake) may follow one image most of the time, while the other images may never be followed by the aversive cue. The participant will need to try to predict whether the aversive cue will occur or not based on which image is shown and will be asked to repeatedly rate on a scale how likely it is that he or she thinks an aversive cue will occur after each image. Lastly, during the session the participant will also be asked to report his or her level of anxiety on a scale from 0 to 100.
Visit 3: Pre-Treatment Behavioral Tests and MR Scan: This visit will be very similar to Visit 2. Participants will participate in the same type of task inside the MR scanner, while the study staff measures reaction time and psychophysiological responding and brain activation. Participants will view the same images he or she did previously, and may experience the same aversive stimulus as during Visit 2. Participants will again be asked to rate how much they expect to experience the aversive stimulus after each image and will also be asked to report their level of anxiety on a scale from 0 to 100.
Visits 4 \& 5: Prolonged Exposure (PE) Sessions 1 \& 2: These sessions will consist of psychoeducation that includes discussion or reactions to trauma , treatment rationale, breathing retraining, and review of SUDS to assess level of distress from 0 to 100 (100=extreme anxiety/distress) when facing fears. One session occurs weekly across 2 weeks.
Visits 6-14: PE Sessions 3-11: These sessions will consist of repeated exposures to trauma memories (imaginal exposure) and avoided situations (in vivo exposure). As is standard, patients will also practice exposures (e.g., listen to tapes of imaginal exposure, carry out in vivo exposure) outside of PE sessions as "homework". At exposure-focused sessions (Sessions 3-11) either THC or PBO will be administered just before the session. One session occurs weekly across 8 weeks.
Visit 15: PE Session 12 [Post-treatment Assessment]: This session will include a review of therapeutic gains/relapse prevention/assessments.
Visit 16: Post-Treatment Behavioral Tests and MR Scan: This visit will be very similar to Visit 2. Participants will participate in the same type of task inside the MR scanner, while the study staff measures reaction time and psychophysiological responding and brain activation. Participants will view the same images he or she did previously, and may experience the same aversive stimulus as during Visit 2. Participants will again be asked to rate how much they expect to experience the aversive stimulus after each image and will also be asked to report their level of anxiety on a scale from 0 to 100.
Visit 17: Post-Treatment Behavioral Tests and MR Scan: This visit will be very similar to Visit 3. Participants will participate in the same type of task inside the MR scanner, while the study staff measures reaction time and psychophysiological responding and brain activation. Participants will view the same images he or she did previously, and may experience the same aversive stimulus as during Visit 3. Participants will again be asked to rate how much they expect to experience the aversive stimulus after each image and will also be asked to report their level of anxiety on a scale from 0 to 100.
Visit 18: 3-Month Follow-Up Treatment Assessment: This session is similar to Visit 15 and will include review of therapeutic gains/relapse prevention/assessments.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Placebo capsule | Placebo comparator | Drug: Placebo capsuleIn a randomized, double-blind, placebo-controlled, between-subjects design, the investigators will administer a single oral dose of dronabinol (7.5mg) or placebo (PBO) approximately two hours prior to each weekly exposure session (up to 9 sessions) in a standard prolonged exposure treatment protocol comprising 12 session overall. Half of the participants will receive 7.5mg dronabinol (n=50) and the other half of the participants will receive placebo (n=50). |
| Dronabinol 7.5 milligram oral capsule | Experimental | Drug: Dronabinol 7.5 milligram oral capsuleIn a randomized, double-blind, placebo-controlled, between-subjects design, the investigators will administer a single oral dose of dronabinol (7.5mg) or placebo (PBO) approximately two hours prior to each weekly exposure session (up to 9 sessions) in a standard prolonged exposure treatment protocol comprising 12 session overall. Half of the participants will receive 7.5mg dronabinol (n=50) and the other half of the participants will receive placebo (n=50). |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Between ages 18-60
- Willing and able to consent to study
- Generally medically and neurologically healthy (including no evidence of intellectual disability or serious cognitive impairment that would interfere with task performance)
- Exposure to Criterion A stressor defined by CAPS-5 and identified by Life Events Checklist-5 (LEC-5)
- Significant PTSD severity as indicated by CAPS-5 diagnosis and/or score >= 25 of at least one month prior to study entry, PTSD is patient's primary concern
Key exclusion criteria (14 listed)
- Positive urine pregnancy test prior to fMRI, self-reported current pregnancy during screening, or planning pregnancy
- Currently breastfeeding/ lactating
- MRI contraindications (e.g., ferrous metal in head/body)
- Pervasive development disorder history
- Traumatic brain injury (TBI) with current cognitive impairment related to TBI
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 |
|---|---|---|
| Placebo capsuleAlso: sugar pillPlacebo is administered just prior to weekly exposure sessions by the oral route and contains only dextrose in opaque capsules. | Drug | Placebo capsule |
| Dronabinol 7.5 milligram oral capsuleAlso: MarinolDronabinol (7.5mg) is administered just prior to weekly exposure sessions by the oral route and is placed in an opaque capsule with dextrose filler. | Drug | Dronabinol 7.5 milligram oral capsule |
Primary outcome
Brain Measures
Time frame: Through study completion, an average of 3 months.
functional magnetic resonance imaging (fMRI) blood oxygen level-dependent (BOLD) percent signal change within region of interests [amygdala; ventromedial prefrontal cortex; hippocampus]
Psychophysiology
Time frame: Through study completion, an average of 3 months.
Skin conductance response (SCR): change in SCR [peak amplitude from 0.5-4.5 sec following stimulus presentation minus average 2 second baseline prior to stimulus presentation].
Expectancy Ratings
Time frame: Through study completion, an average of 3 months.
To assess the change in expected likelihood that an aversive cue (e.g. noise burst or shock) will occur or not based on while slide was shown, participants will repeatedly rate their expectancy of the aversive cue using a button box on a scale from 1 to 3 [1 = certain that the aversive cue will be presented; 2 = certain that the aversive cue will not be presented; 3 = uncertain whether the aversive cue will be presented].
PTSD Checklist (PCL-5)
Time frame: Through study completion, an average of 3 months.
To track PTSD symptom change for each participant. The PCL-5 is a 20-item questionnaire. The self-report rating scale is 0-4 for each symptom: "Not at all," "A little bit," Moderately," "Quite a bit," and "Extremely", respectively. A total symptom severity score (range - 0-80) can be obtained by summing the scores for each of the 20 items.
Clinician Administered PTSD Scale for Diagnostic and Statistical Manual (DSM)-5 (CAPS-5)
Time frame: Through study completion, an average of 3 months.
To track PTSD symptom change for each participant. The CAPS is the gold standard in PTSD assessment. The CAPS is a 30-item structured interview. In addition to assessing the 20 DSM-5 PTSD symptoms, questions target the onset and duration of symptoms, subjective distress, impact of symptoms on social and occupational functioning, improvement in symptoms since a previous CAPS administration, overall response validity, overall PTSD severity, and specifications for the dissociative subtype. The assessor combines information about frequency and intensity of an item into a single severity rating. Total symptom severity score is calculated by summing severity scores for the 20 DSM-5 PTSD symptoms. The five-point CAPS-5 symptom severity rating scale is used for all symptoms (0, Absent; 1, mild; 2, Moderate/threshold; 3, Severe/markedly elevated; 4, Extreme/incapacitating). Total CAPS-5 symptom severity scores range from 0-80, with higher scores indicating worse PTSD symptom severity.
Subjective Units of Distress Scale (SUDS)
Time frame: Through study completion, an average of 3 months.
To assess the change in level of distress from 0 to 100 when facing fears. The higher the number on the scale the more severe the level of distress experienced.
7 secondary outcomes
Visual Analogue Scale of Mood (VAS)
Time frame: Through study completion, an average of 3 months.
Drug Effects Questionnaire (DEQ)
Time frame: Through study completion, an average of 3 months.
Addiction Research Center Inventory (ARCI)
Time frame: Through study completion, an average of 3 months.
State-Trait Anxiety Inventory (STAI)
Time frame: Through study completion, an average of 3 months.
End of Session Questionnaire (ESQ)
Time frame: Through study completion, an average of 3 months.
Heart Rate
Time frame: Through study completion, an average of 3 months.
Blood Pressure
Time frame: Through study completion, an average of 3 months.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jul 2025.
- Derived from this study: PubMed 41270825Rabinak CA, Kilgore PE, Lumley MA, Rauch SAM. Randomized trial of delta-9-tetrahydrocannabinol (THC) versus placebo to augment the effects of prolonged exposure therapy on fear extinction learning in post-traumatic stress disorder: Study rationale and protocol. Contemp Clin Trials. 2026 Jan;160:108148. doi: 10.1016/j.cct.2025.108148. Epub 2025 Nov 19.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Christine A Rabinak, PhD principal investigator
Wayne State University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Dronabinol 7.5 milligram oral capsule in people with Posttraumatic Stress Disorder, run by Wayne State University at 1 site 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 5 inclusion and 14 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: finished, as of the sponsor's last update on 11 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Brain Measures (time frame: Through study completion, an average of 3 months.). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04080427, which also lists 1 linked publication.
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 11 Jul 2025.