Drug Effect
Conditions
Brief summary
This study will investigate the effects of salvinorin A on human brain activity and connectivity using functional magnetic resonance imaging (fMRI) methods. An inhalation route of administration will be used as it is the most common route for contemporary use of Salvia divinorum, a plant containing salvinorin A.
Detailed description
Volunteers will undergo two experimental sessions that include the inhalation of salvinorin A. The first session will be completed in a comfortable space furnished as a living room, and the second session will be conducted within a magnetic resonance imaging (MRI) scanner.
Interventions
DRUGSalvinorin A
Salvinorin A, blinded doses
Sponsors
National Institute on Drug Abuse (NIDA)
Johns Hopkins University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Masking description
Participants will not be aware of exact doses salvinorin A (i.e. they will be told they may receive placebo or up to a moderately high dose of of salvinorin A).
Eligibility
Sex/Gender
ALL
Age
21 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Have given written informed consent * Have a high school level of education * Have a history of hallucinogen use and experience with an inhaled psychoactive drug. * Recent experience (within the past year) with an inhaled psychoactive drug. * Agree to consume approximately the same amount of caffeine-containing beverage (e.g., coffee, tea) that he/she consumes on a usual morning, before arriving at the research unit on the mornings of drug session days. If the volunteer does not usually consume caffeinated beverages, he or she must agree not to do so on session days * Agree to refrain from using any psychoactive drugs, including alcoholic beverages and any tobacco product such as cigarettes or any other nicotine product such as e-cigarettes, within 24 hours of each drug administration. Exceptions include daily use of caffeine. * Be healthy and psychologically stable as determined by screening for medical problems via a personal interview, a medical questionnaire, a physical examination, and routine medical blood and urinalysis laboratory tests * Agree that for one week before each session, he/she will refrain from taking any nonprescription medication, nutritional supplement, or herbal supplement except if approved by the study investigators. Exceptions will be evaluated by the study investigators and will include acetaminophen, non-steroidal anti-inflammatory drugs, and common doses of vitamins and minerals * Agree not to take any Pro-re-nata (PRN) prescription medications on the mornings of the sessions
Exclusion criteria
* Women who are pregnant (as indicated by a positive urine pregnancy test assessed at intake and before each drug session) or nursing; women who are of child-bearing potential and sexually active who are not practicing an effective means of birth control * Cardiovascular conditions: coronary artery disease, stroke, angina, uncontrolled hypertension, or Transient Ischemic Attack (TIA) in the past year * Seizure disorder or epilepsy with history of seizures * Insulin-dependent diabetes; if taking oral hypoglycemic agent, then no history of hypoglycemia * Currently taking psychoactive prescription medication on a regular (e.g., daily) basis * More than 25% outside the upper or lower range of ideal body weight * Current or past history of meeting Diagnostic and Statistical Manual (DSM)-V criteria for schizophrenia, psychotic disorder (unless substance-induced or due to a medical condition), dissociative disorder, bipolar I or II disorder, an eating disorder * Current or past history of substance-induced psychosis. * Current or past history within the last 2 years of meeting DSM-5 criteria for moderate or severe alcohol or substance use disorder (excluding caffeine) * Daily or more frequent tobacco or nicotine use * Current severe obsessive-compulsive disorder, dysthymic disorder, or panic disorder. * Current, severe, major depression * Have a first or second degree relative with schizophrenia, psychotic disorder (unless substance induced or due to a medical condition), or bipolar I or II disorder * Has a psychiatric condition judged to be incompatible with establishment of rapport or safe exposure to salvinorin A * Head trauma, traumatic brain injury, or concussion with loss of consciousness for \>2 minutes * Claustrophobia incompatible with MRI scanning * Medical device incompatible with MRI scanning (e.g. cardiac pacemaker, implanted cardiac defibrillator, aneurysm brain clip, inner ear implant) * Prior history as a metal worker and/or certain metallic objects in the body -- must complete MRI screening form and be approved by MRI technologist before each scan * Left-handedness (assessed by the Edinburgh Handedness Inventory)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | Pre salvinorin A administration and 20 minutes post-salvinorin A administration | Changes in brain activity from before to after salvinorin A administration within canonical brain networks \[medial frontal (MF), frontoparietal (FP), default mode (DM), subcortical-cerebellum (SubC), somatosensory-motor (SM), medial visual (MedV), occipital pole (OccP), and lateral visual or (LatV)\] will be assessed using blood-oxygenation level dependent (BOLD) techniques. Due to salvinorin A's potential confounding influence on blood flow, activity was assessed by looking at the variance in the BOLD signal. Variance in BOLD signal is a dimensionless variable that can vary from 0 to infinity. |
| Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | Pre-salvinorin A administration and 20 minutes post-salvinorin A administration | Changes in within and between network functional connectivity (FC) from pre to post-salvinorin A (SA) administration in several brain networks \[medial frontal (MF), frontoparietal (FP), default mode (DM), subcortical-cerebellum (SubC), somatosensory-motor (SM), medial visual (MedV), occipital pole (OccP), lateral visual or (LatV)\] is assessed via analysis of blood-oxygenation level dependent (BOLD) data. FC is the association between the BOLD activity of two regions over time. This is measured with a Pearson's correlation that is made parametric via z-transformation. FC within a network is the average of all possible pairwise combinations of z-transformed correlations within a network. FC between two networks is the average of all possible pairwise combinations of z-transformed correlations between two networks. We looked at the change in FC from pre to post-SA averaged across participants (this also gives a measure of dispersion). |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Salvinorin A Administration All volunteers will be assigned to the salvinorin A administration arm.
Salvinorin A: Salvinorin A, blinded doses | 13 |
| Total | 13 |
Baseline characteristics
| Characteristic | Salvinorin A Administration |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 13 Participants |
| Age, Continuous | 35.46 years STANDARD_DEVIATION 8.48 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 12 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 1 Participants |
| Lifetime uses of Salvia divinorum | 22.08 number of times STANDARD_DEVIATION 48.7 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants |
| Race (NIH/OMB) White | 11 Participants |
| Region of Enrollment United States | 13 Participants |
| Sex: Female, Male Female | 1 Participants |
| Sex: Female, Male Male | 12 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 12 |
| other Total, other adverse events | 0 / 12 |
| serious Total, serious adverse events | 0 / 12 |
Outcome results
Primary
Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal
Changes in brain activity from before to after salvinorin A administration within canonical brain networks \[medial frontal (MF), frontoparietal (FP), default mode (DM), subcortical-cerebellum (SubC), somatosensory-motor (SM), medial visual (MedV), occipital pole (OccP), and lateral visual or (LatV)\] will be assessed using blood-oxygenation level dependent (BOLD) techniques. Due to salvinorin A's potential confounding influence on blood flow, activity was assessed by looking at the variance in the BOLD signal. Variance in BOLD signal is a dimensionless variable that can vary from 0 to infinity.
Time frame: Pre salvinorin A administration and 20 minutes post-salvinorin A administration
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | OccP activity | 16.96 variance in BOLD signal | Standard Deviation 366.9 |
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | MF activity | 15.65 variance in BOLD signal | Standard Deviation 74.38 |
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | FP activity | 18.06 variance in BOLD signal | Standard Deviation 117.54 |
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | DM activity | 23.39 variance in BOLD signal | Standard Deviation 229.3 |
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | SubC activity | 8.93 variance in BOLD signal | Standard Deviation 40.91 |
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | SM activity | 13.06 variance in BOLD signal | Standard Deviation 79.58 |
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | MedV activity | 26.15 variance in BOLD signal | Standard Deviation 406.07 |
| Salvinorin A Administration | Changes in Brain Activity (fMRI) as Assessed by Variance in BOLD Signal | LatV activity | 9.30 variance in BOLD signal | Standard Deviation 77.47 |
Comparison: T test on the change in network activity across all networks, from before to after salvinorin A administration.p-value: 0.006t-test, 2 sided
Primary
Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation
Changes in within and between network functional connectivity (FC) from pre to post-salvinorin A (SA) administration in several brain networks \[medial frontal (MF), frontoparietal (FP), default mode (DM), subcortical-cerebellum (SubC), somatosensory-motor (SM), medial visual (MedV), occipital pole (OccP), lateral visual or (LatV)\] is assessed via analysis of blood-oxygenation level dependent (BOLD) data. FC is the association between the BOLD activity of two regions over time. This is measured with a Pearson's correlation that is made parametric via z-transformation. FC within a network is the average of all possible pairwise combinations of z-transformed correlations within a network. FC between two networks is the average of all possible pairwise combinations of z-transformed correlations between two networks. We looked at the change in FC from pre to post-SA averaged across participants (this also gives a measure of dispersion).
Time frame: Pre-salvinorin A administration and 20 minutes post-salvinorin A administration
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SubC-OccP between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.05 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF within-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.1 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | FP within-network connectivity | .05 Z-transformed Pearson's correlation | Standard Deviation 0.07 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | DM within-network connectivity | .09 Z-transformed Pearson's correlation | Standard Deviation 0.06 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SubC within-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.03 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SM within-network connectivity | .05 Z-transformed Pearson's correlation | Standard Deviation 0.09 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MedV within-network connectivity | .06 Z-transformed Pearson's correlation | Standard Deviation 0.1 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | OccP within-network connectivity | .05 Z-transformed Pearson's correlation | Standard Deviation 0.09 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF-OccP between-network connectivity | .05 Z-transformed Pearson's correlation | Standard Deviation 0.1 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | LatV within-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.08 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF-FP between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.08 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF-DM between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.09 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF-LatV between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.06 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF-SubC between-network connectivity | .00 Z-transformed Pearson's correlation | Standard Deviation 0.03 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | FP-DM between-network connectivity | .03 Z-transformed Pearson's correlation | Standard Deviation 0.05 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | FP-SubC between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.03 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF-SM between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.09 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MF-MedV between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.08 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | FP-SM between-network connectivity | .03 Z-transformed Pearson's correlation | Standard Deviation 0.08 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | FP-MedV between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.07 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | FP-OccP between-network connectivity | .04 Z-transformed Pearson's correlation | Standard Deviation 0.06 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | FP-LatV between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.05 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | DM-SubC between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.03 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | DM-SM between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.06 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | DM-MedV between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.06 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | DM-OccP between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.09 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | DM-LatV between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.06 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SubC-SM between-network connectivity | .00 Z-transformed Pearson's correlation | Standard Deviation 0.03 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SubC-MedV between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.05 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SubC-LatV between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.04 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SM-MedV between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.12 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SM-OccP between-network connectivity | .04 Z-transformed Pearson's correlation | Standard Deviation 0.1 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | SM-LatV between-network connectivity | .01 Z-transformed Pearson's correlation | Standard Deviation 0.1 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MedV-OccP between-network connectivity | .02 Z-transformed Pearson's correlation | Standard Deviation 0.14 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | MedV-LatV between-network connectivity | .06 Z-transformed Pearson's correlation | Standard Deviation 0.1 |
| Salvinorin A Administration | Changes in Brain Connectivity (fMRI) as Assessed by Pearson's Correlation | OccP-LatV between-network connectivity | .03 Z-transformed Pearson's correlation | Standard Deviation 0.11 |
Comparison: T test on the change in within- and between-network connectivity across all values, from before to after salvinorin A administration.p-value: 0.001t-test, 2 sided