Supplemental information 12 2 11 18 1 16 THC (ng/dl) A 9 8 7 6 5 4 3 2 1 5 1 15 2 Minutes 25 ΔTHC level B 14 12 1 8 6 4 2-2 -4 y = 11.92x + 42.11 R² =.1375 y =.196x + 29.63 R² =.2977 y =.1513x +.8471 R² =.1642.4.8 1.2 1.6 FPD score 2 21 29 THC-COOH (ng/dl) 18 16 14 12 1 8 6 4 2-2 5 1 15 2 25 ΔTHC-COOH level 25 2 15 1 5-5 y =.8494x + 12.53 R² =.2398 y =.467x + 8.575 R² =.1621 y =.4.8 1.2 1.6 2 C -5 Minutes D -1 FPD score Placebo Low dose High dose Figure S1: Blood levels of Δ 9 -THC and THC-COOH. A: THC by time. B: Peak change in THC level by family history of alcohol misuse (FPD). C: THC-COOH by time. D: Peak change in THC-COOH level by family history of alcohol misuse (FPD). THC=Δ 9 -tetrahydrocannabinol; THC-COOH=11-nor-9-carboxy-THC.
Supplemental information Screening Process All subjects underwent a structured psychiatric interview for DSM-IV (9) and were carefully screened for any Axis I lifetime psychiatric or substance abuse disorder (excluding nicotine) and FH of psychotic Axis I disorder. The history was confirmed by interview with a spouse or family member. Past-month alcohol use was quantified using a Time-Line-Follow- Back (TLFB) approach and past-month cannabis use was quantified using the Marijuana Lifetime Use-Revised scale. Finally, volunteers underwent a general physical and neurologic examination, EKG, and laboratory tests (serum electrolytes, liver function tests, complete blood count with differential and urine toxicology including urine Δ 9 -THC and 11-nor-9-carboxy-THC and pregnancy test if female).
Calculation of Family History Score Family Pattern Density (FPD) scores were constructed from two previously validated methods of calculating family history; Family History Density (FHD) and Family Pattern of Alcoholism (FPA), similarities and differences between which are illustrated in Figure S2. The FHD method weights family history score based on degree of genetic relatedness, with parents each counting as ½ and grandparents as, for a possible FHD score of to 2. In this case, the father plus two grandparents generate a family history score of 1. However, brothers, sisters, aunts and uncles are not considered. The FPA method adds weighting for relatives but does not compensate for genetic distance. Problem drinkers are rated as 1 and non-problem drinkers are rated as, but aunts, uncles, brothers and sisters are weighted according to how many there are. For example, two alcoholic brothers out of four siblings generates a score of ½; one alcoholic paternal aunt out of two paternal aunts also rates a ½. The FPD method includes the weighted relatives of FPA with the genetic loading of FHD, generating an FH score that ranges from to 3. In this genogram, the two alcoholic grandparents count point each, the father counts for ½ a point, one out of two paternal aunts adds another 1/8, and half of the brothers weighted at ½ yields another quarter, for a total family history score of 1¾. In general, the more information considered in calculation of the FH score, the more robust the results appear to be.
1 1 ½ ½ 1 1 A 1 B 1 ½ C ½ ½ Supplemental Figure : Comparison of different methods of calculating FH: The proband, or research subject, is the red double circle. Family members with alcohol misuse are indicated in green. A: Family History Density (FHD), which weights parents and grandparents only generates an FH score of 1 (range -2). B: Family Pattern of Alcoholism (FPA), which counts all first- and seconddegree relatives, but does not weight by genetic distance, generates an FH score of 4½ (range -9). C: Family Pattern Density (FPD), which counts all first- and second-degree relatives and also weights by genetic distance, generates an FH score of 1¾ (range -3).
Description of outcome measures Δ 9 -THC and 11-hydroxy-THC: Δ 9 -THC and its principal active metabolite 11-hydroxy-THC were measured in a subset of the volunteers (8 FH-, 7 FH+, and 6 FH++) using a GC/MS assay that has an intra- and interassay RSD% of <1% at 1 ng/ml with.5 ng/ml as the lower limit of detection in order to exclude a pharmacokinetic explanation for hypothesized group differences. Blood sampled at the beginning of each test day also permitted the detection of confounding cannabis use between test days. Biphasic Alcohol Effects Scale (BAES): This is a 7-item instrument that measures the stimulating and sedating effects of alcohol on a scale from 1 to 1 (Martin et al, 1993). Δ 9 -THC has been reported to produce initial stimulatory effects followed by predominantly sedating effects in a manner similar to alcohol. Cambridge Neuropsychological Test Automated Battery (CANTAB) Cognitive tasks are part of the CANTAB a computerized cognitive test battery that assesses cognition using nonverbal stimuli with touch-screen methodology(cantab). Parallel versions of some of the CANTAB tests are available for repeated measures and have high test retest reliability. A motor screening task is administered before all other tests to correct for motor dysfunction that might impact test performance. It introduces the volunteer to the touch-screen and acts as a training procedure to ensure that the volunteer can touch the screen accurately. It simultaneously screens for visual and movement problems and ensures that the volunteer can hear, understand and follow simple instructions. A series of crosses is shown at different locations on the screen. After instruction on the correct way to point using the forefinger of the dominant hand, the volunteers must touch the crosses in turn. Reaction Time (RTI): This is a latency task with a comparative history (the five choice task) that uses a procedure to separate response latency from movement time. The participant must react as soon as a yellow dot appears in one of five locations, and the participant must sometimes respond by using the press-pad, sometimes by touching the screen, and sometimes both. Spatial Working Memory (SWM): This task requires participants to search through a number of boxes on the screen in order to locate blue tokens, which are hidden inside the boxes. The key instruction is that once a token has been found inside a particular box, that box will not be used again to hide another token in the sequence. Therefore, volunteers should not return to a box
that contained a token. In order to do this the information (i.e. the box in which a token has been found) has to be maintained in working memory. Since each box is used only once, the maximum number of tokens corresponds to the number of boxes on the screen. There are four test trials for each level of difficulty (4, 6 and 8 boxes). The accuracy of performance is recorded by error scores. Two types of error are possible 1) within-search errors which are recorded if a box is searched more than once during a single search sequence, and 2) between-search errors which are recorded if a volunteer opens a box in which a token has already been found. Higher error scores reflect poorer performance. Stockings of Cambridge (SOC): This is a spatial planning test. The volunteer is shown two displays containing three colored balls, presented so they can be perceived as stacks of colored balls in stockings. In each trial, the volunteer must move the balls in the lower display to copy the pattern shown in the upper. A later motor control task, in which the volunteer simply copies earlier moves, allows planning time (versus movement time) to be calculated and taken, relative to the number of moves required to complete each trial, as a measure of the volunteer's planning ability. Rapid Visual Information Processing (RVIP): This is a test of vigilance (sustained attention) with a small working memory component. A white box appears in the center of the computer screen, inside which digits, from 2 to 9, appear in a pseudo-random order, at the rate of 1 digits per minute. Volunteers are instructed to detect consecutive odd or even sequences of digits (e.g. 2-4-6, 3-5-7) and to register responses using the press-pad. Initially, the computer prompts the volunteer when sequences appear and gives feedback when the pad is pressed. As the practice session progresses, these cues are gradually phased out, and in the assessment phase, no cues or feedback are given. A' is the signal detection measure of sensitivity to errors, regardless of error tendency (range. to 1.; bad to good). This metric is a measure of how good the volunteer is at detecting target sequences. Clinician Administered Dissociative Symptoms Scale (CADSS): Perceptual alterations were measured using the CADSS, a 5-point Likert scale consisting of 19 self-report items and eight clinician-rated items that we have shown previously to be also sensitive to Δ 9 -THC effects (D'Souza et al, 24). The scale measures alterations in perceptions of the environmental, time, and body, feelings of unreality, and subjective memory impairment.
Rey Auditory Verbal Learning Test (RAVLT): This is a 15-word learning task of verbal memory and hippocampal function (Rosenberg et al, 1984). The task consists of five learning trials, an interference list, and free delayed recall and recognition. A different version of the RAVLT, which has five versions, was administered on each test day by a trained rater under the supervision of a research neuropsychologist and counterbalanced across volunteers. Drug Liking and Drug Discrimination 1. Similarities to alcohol effects: Please score on this line how similar the effects of the drug were to alcohol? The line was 1 cms long and without any markings. 2. Comparison to # standard alcohol drinks: Please estimate the intensity of effects that you experienced in terms of number of standard alcoholic drinks? (e.g.,, 1, 2, 3 3. Drug-Liking : Please score on this line how much you enjoyed the effects of the drug. The line was 1 cms long and without any markings. Follow-up assessments (1, 3, 6 months): Subjects were asked to report, for the period since their last contact with the research team, answers to the following questions: (1) Do you think your exposure to THC in the lab has changed your cannabis use? (2) How intense has your desire for cannabis been since your last test day or questionnaire? (3) Since your last challenge day or questionnaire, how many times per week have you used cannabis? Cannabis use reported at screening was compared with cannabis use reported at follow-up in order to determine whether any reported change in desire to use cannabis at follow-up correlated with change in actual cannabis use.
Secondary Analyses: Analysis of Results Using FPA Method In order to determine to what extent an alternate FH calculation method would influence the results, we repeated the analyses using FPA (Table S1). Our primary interest was interactions between FH and dose on peak change from baseline for all repeated measures.
Supplemental Table 1: Cognitive, Subjective, Physiologic, and Drug-Discrimination Effects Cognitive Measures Main effects Interactive effects Dose FPA FPA x dose F-value p F-value p F-value p RAVLT Total immediate free recall 7.36.2 1.9.31.12.89 Long delayed free recall 4.35.2.82.37.35.71 Perseverations (log transformed).11.9.89.35.24.79 Non-list intrusions (log transformed 5.38.7.88.36 1.3.36 Total intrusions 7.55.1.72.4.13.87 CANTAB 5C-RTI Reaction time 2.9.6 1.82.19.88.42 SWM Between errors 4.19.2.97.33.5.95 (8 boxes) Total errors 3.76.3.81.38.4.67 SOC Mean initial thinking time 2.47.9 1.28.27 1.82.17 (5 moves) Mean subsequent thinking time 1.1.34.14.71 1.39.26 Problem solved in minimum moves.97.39.64.43.7.92 RVIP A 1.6.35.18.67.72.49 Subjective Measures Main effects Interactive effects Dose FPA FPA x dose F-value p F-value p F-value p VAS CADSS BAES High (log transformed) 8.9 <.1 1.79.19 2.7.8 Calm.37.69 1.31.26.5.95 Anxious 3.1.6.17.68 2.3.14 Panic (log transformed) 4.3.2.42.52 2.92.6 Tired 4.2.2.98.33.63.53 Patient (log transformed) 11.2.3 4.39.5 4.77.2 Clinician (log transformed) 49.8 <.1 2.84.1.27.77 Stimulation.77.47.2.88.94.4 Sedation 13 <.1 1.2.32.94.39 Physiological measures
Systolic Blood Pressure 1.11.34 1.67.2.26.77 Diastolic Blood Pressure 1.33.27 3.39.7.33.72 Heart Rate 6.51.5.1.93.79.46 Drug discrimination effects Cannabis similarity 13.7 <.1.27.6 1.36.26 Alcohol similarity 13.4 <.1 1.74.2.39.68 Drug liking.28.76.1.92.5.61 5C-RTI= 5-Choice Reaction Time; BAES=Biphasic Alcohol Effects Scale; CADSS= Clinician Administered Dissociative Symptoms Scale; CANTAB=Cambridge Neuropsychological Test Automated Battery; FPA=Family Pattern Analysis; RAVLT=Rey Auditory Verbal Learning Test; RVIP= Rapid Visual Information Processing; SOC=Stockings of Cambridge; SWM= Spatial Working Memory task; VAS=Visual Analog Scale. Significant effects are indicated by boldface.