This human laboratory study will use cognitive, behavioral, and subjective measures to characterize impairment associated with co-use of alcohol and vaporized cannabis. Participants (n=32) will complete 7 double-blind, double-dummy outpatient sessions in randomized order. In each session, participants will self-administer placebo (0 mg THC) or active vaporized cannabis (5 or 25 mg THC, via a handheld vaporizer called the Mighty Medic) and a placebo drink (BAC 0.0%) or alcohol drink calculated to produce a breath alcohol concentration (BAC) of 0.05%. Participants will also complete a positive control session in which the participant administers placebo cannabis and alcohol at a target BAC of 0.08% (the legal threshold for driving impairment in most U.S. states).
This study will be conducted at the Johns Hopkins Behavioral Pharmacology Research Unit (BPRU). Participants will complete a screening visit, and, if eligible, will then complete 7 experimental drug administration sessions in randomized order where the participant will vaporize cannabis-containing capsules (or "pods") (containing 0, 5, or 25mg THC) with a drink that contains no alcohol or alcohol (alcohol-containing drinks will be calculated to produce a breath alcohol concentration, BAC, of 0.05%). There is also a positive control session where participants will vaporize placebo cannabis with an alcohol drink calculated to produce a BAC of 0.08%. Each session will last approximately 8 hours and will be separated by at least 48 hours to allow for sufficient drug washout. Participants may complete up to 2 sessions per week. Drugs will be administered in a double-blind and double-dummy fashion (i.e., participants will always receive both active or placebo cannabis and active or placebo alcohol). During each session, a battery of assessments including blood collection, subjective questionnaire administration, cognitive performance testing, and simulated driving will be conducted.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Enrollment
90
Cannabis will be vaporized using the Mighty Medic
Alcohol will be orally ingested via a flavored drink
Placebo cannabis (i.e., water vapor) will be vaporized using the Mighty Medic.
A non-alcoholic, placebo, flavored drink will be orally ingested.
Johns Hopkins Behavioral Pharmacology Research Unit
Baltimore, Maryland, United States
RECRUITINGDRUID application global impairment score
Acute cognitive and behavioral impairment will be assessed with global impairment score (range 0-100) on the DRUID app (higher scores indicate greater impairment).
Time frame: Up to 6 hours
Correct Trials on Paced Auditory Serial Addition Task (PASAT)
Computerized version of Paced Auditory Serial Addition Task will be administered to assess working memory performance. Will report the total correct trials out of 90 recorded (lower scores indicate worse performance). Score ranges from 0-90, with 0 representing no correct trials and 90 representing 100% correct trials.
Time frame: Up to 6 hours
Correct Trials on the Digit Symbol Substitution Task (DSST)
Computerized version of Digit Symbol Substitution Task will be administered to assess psychomotor performance. Will report the total correct trials in 90 seconds (lower scores indicate worse performance). There is no maximum score, with a score of 0 representing either no trials completed or no correct trials. The score reflects the number of correct trials.
Time frame: Up to 6 hours
Cumulative score on Field Sobriety Tests
Impairment will be assessed using a battery of standard field sobriety tests including: the Horizontal Gaze Nystagmus Test (HGN), the Walk and Turn, the One Leg Stand, and the Modified Romberg Balance. The cumulative amount of clues observed across these tasks (out of a possible 22 clues) will be reported.
Time frame: Up to 6 hours
Drug Effect Questionnaire (DEQ) - Feel Drug Effect
The DEQ will be used to obtain subjective ratings of "feel drug effects". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Up to 6 hours
Drug Effect Questionnaire (DEQ) - Feel High
The DEQ will be used to obtain subjective ratings of "feel high". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Up to 6 hours
Drug Effect Questionnaire (DEQ) - Confidence to Drive
The DEQ will be used to obtain subjective ratings of "confidence to drive". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Up to 6 hours
Drug Effect Questionnaire (DEQ) - Willingness to Drive
The DEQ will be used to obtain subjective ratings of "willingness to drive". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Up to 6 hours
Biphasic alcohol effects scale (BAES) - Sedative Score
The BAES is used to assess sedative and stimulant subjective effects of alcohol. There are 7 sedative-related questionnaire items, each presented on a scale of 0 (not at all) to 10 (extremely), which are integrated to produce an overall sedative score (0-70).
Time frame: Up to 6 hours
Biphasic alcohol effects scale (BAES) - Stimulant Score
The BAES is used to assess sedative and stimulant subjective effects of alcohol. There are 7 stimulant-related questionnaire items, each presented on a scale of 0 (not at all) to 10 (extremely), which are integrated to produce an overall stimulant score (0-70).
Time frame: Up to 6 hours
Subjective high assessment scale (SHAS)
For the SHAS, participants are presented with 13 questionnaire items, displayed on a visual analog scale anchored from 0 (normal) to 10 (extremely), which assess subjective effects of alcohol. These items are integrated to produce an overall SHAS score (0-130)
Time frame: Up to 6 hours
Driving performance as assessed by standard deviation of lateral position (SDLP)
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. SDLP (measured in cm) will be determined during each drive. This measure is a composite index of lateral control and incorporates lane weaving, swerving, and over-correcting. SDLP is the gold standard of quantifying the magnitude of driving impairment from drugs and alcohol and has excellent predictive validity to actual driving. Scores range from 0 to no upper limit. Higher scores represent higher magnitude of driving impairment.
Time frame: Up to 6 hours
Driving performance as assessed by composite drive score
Driving impairment will be assessed via a composite drive score (higher scores indicate greater impairment). The composite drive score is derived by integrating various driving outcomes. There is no upper or lower limit to possible scores.
Time frame: Up to 6 hours
Driving performance as assessed by standard deviation of speed (SDSP)
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. SDSP will be determined during each drive; this measure quantifies the variability in speed (in MPH) observed.
Time frame: Up to 6 hours
Driving performance (mean speed)
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. Mean speed (in MPH) over the course of each drive will be determined.
Time frame: Up to 6 hours
Driving performance (number of speed exceedances)
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The cumulative number of times participants exceed the allowable speed limit during each drive.
Time frame: Up to 6 hours
Driving performance (number of accidents)
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The cumulative number of accidents (including car collisions, pedestrians hit, etc.) during each drive.
Time frame: Up to 6 hours
Driving performance (total rule violations)
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The cumulative number of rule violations (including number of missed stop signs, illegal turns, speed exceedances, etc.) during each drive.
Time frame: Up to 6 hours
Driving performance (distance to lead vehicles)
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The mean distance (in meters) maintained to lead vehicles during car-following segments of each drive.
Time frame: Up to 6 hours
Attempted Trials on the Digit Symbol Substitution Task (DSST)
Computerized version of Digit Symbol Substitution Task will be administered to assess psychomotor performance. The number of attempted trials will be recorded
Time frame: Up to 6 hours
Percentage Correct on attempted trials on the Digit Symbol Substitution Task (DSST)
Computerized version of Digit Symbol Substitution Task will be administered to assess psychomotor performance. Percentage of correct trials out of those attempted will be recorded
Time frame: Up to 6 hours
Reaction time on Paced Auditory Serial Addition Task
Computerized version of Paced Auditory Serial Addition Task will be administered to assess working memory performance. The mean reaction time (in milliseconds) to select correct responses will be recorded.
Time frame: Up to 6 hours
Field Sobriety Test - Score on Horizontal Gaze Nystagmus Test
Impairment will be assessed using performance on the Horizontal Gaze Nystagmus Test (HGN). Total score will be recorded (out of possible 6 clues, score ranges from 0-6) with higher scores indicating higher impairment.
Time frame: Up to 6 hours
Field Sobriety Test - Score on Walk and Turn test
Impairment will be assessed using performance on the the Walk and Turn. Total score will be recorded (out of a possible 8 clues, score ranges from 0-8) with higher scores indicating higher impairment.
Time frame: Up to 6 hours
Field Sobriety Test - Score on One Leg Stand
Impairment will be assessed using performance on the One Leg Stand test. Total score will be recorded (out of a possible 4 clues, score ranges from 0-4) with higher scores indicating higher impairment.
Time frame: Up to 6 hours
Field Sobriety Test - Score on Modified Romberg Balance
Impairment will be assessed using performance on the Modified Romberg Balance test. Total score will be recorded (out of a possible 4 clues, score ranges from 0-4)) with higher scores indicating higher impairment.
Time frame: Up to 6 hours
Drug Effect Questionnaire - Like Drug Effect
The DEQ will be used to obtain subjective ratings of "like drug effect". Scores range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Up to 6 hours
Drug Effect Questionnaire - Want more
The DEQ will be used to obtain subjective ratings of "want more". Scores range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Up to 6 hours
Drug Effect Questionnaire - Dislike Drug Effect
The DEQ will be used to obtain subjective ratings of "dislike drug effect". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Up to 6 hours
Pharmacokinetics - CMax for THC and THC metabolites
Whole blood concentrations of THC, 11-OH- THC, and THCCOOH will be measured using quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis. The maximum concentration (Cmax) is determined as the highest concentration reached for each individual. Characterizing these cannabinoids will allow for adequate control for individual differences in drug absorption and metabolism in statistical analyses and assist with interpretation of subjective and behavioral outcomes.
Time frame: Up to 6 hours
Pharmacokinetics - AUC for THC and THC metabolites
Whole blood concentrations of THC, 11-OH- THC, and THCCOOH will be measured using quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis. The area under the curve (AUC) is calculated across all timepoints, minus the baseline. Characterizing these cannabinoids will allow for adequate control for individual differences in drug absorption and metabolism in statistical analyses and assist with interpretation of subjective and behavioral outcomes.
Time frame: Up to 6 hours
Pharmacokinetics - Breath Alcohol Concentration (BAC)
BAC will be measured using the Alco-Sensor IV. Measuring BAC is needed to confirm that participants reached the targeted BAC for a given session and to confirm adherence to pre-session alcohol abstinence requirements.
Time frame: Up to 6 hours