Pharmacokinetics of GH001 in Healthy Volunteers

For PK analyses, blood samples will be collected before and up to 4 hours after the administration of GH001 to determine 5-MeO-DMT and bufotenine serum concentrations.

Adverse events reported in the study and coded by MedDRA.

Clinically significant changes in ECG include any significant change in rate or rhythm as determined by the principal investigator

Vital signs include heart rate (beats per minute), blood pressure (mmHg), respiratory rate (breaths per minute), oxygen saturation (%), and temperature (degrees celsius). Changes are defined as any clinically significant change from baseline as determined by the principal investigator

Safety laboratory analyses are analyses of blood samples (biochemistry, hematology) and urine samples (urinalysis). Changes are defined as any clinically significant change from baseline as determined by the principal investigator.

Peak Flow is assessed using a standard peak flow respirometer, with the assessment done three times and the best of the three scores recorded as the final score (liters/minute).

The Modified Observer's Assessment of Alertness and Sedation scale (MOAA/S) will be completed before and after GH001 dosing. Scored from 0 (deep sedation) to 5 (alert)

Change from baseline in the Clinician Administered Dissociative States Scale (CADSS). The CADSS comprises 19 subjective items, ranging from 0 'not at all' to 4 'extremely. Summed together, these subscales form a total dissociative score. Combined score ranges from 0 to 76.

Assessment of Discharge Readiness on the administration day by the Principal Investigator, using the Clinical Global Assessment of Discharge Readiness (CGADR).

Change from baseline in the Brief Psychiatric Rating Scale (BPRS). A scale to measure psychiatric symptoms. Each symptom is rated 1-7 and a total of 18 symptoms are scored. Combined score ranges from 18 to 126.

Change from baseline in the Columbia-Suicide Severity Rating Scale (C-SSRS). A detailed questionnaire assessing both suicidal behaviour and suicidal ideation. No combined score is created.

The Peak Experience Scale (PES) is a Visual Analogue Scale scored from 0-100

The MEQ30 is a validated procedure for assessing the extent of the psychoactive effects experienced by a subject. The validated MEQ30 uses thirty assessment questions across four areas of experience, all scored from 0 to 5.

Completed by the subject after GH001 administration and assesses seven factors (grief, fear, death, insanity, isolation, physical distress, and paranoia) all scored from 0 to 5.

The duration of the experience, defined as time in minutes from drug administration to time when the subject reports that any psychoactive symptoms have subsided will be recorded.

Change from baseline in the Psychomotor Vigilance Test (PVT). A computerized test assessing the reaction time in response to a visual stimulus. Outcome measures are Response Time and the number of attentional lapses (Response Time ≥ 500 msec).

The AVLT is one of the most widely used word learning tests in clinical research and practice. The test is based on successive auditory presentations of 15-word lists followed by attempted recall. The AVLT outcome measures are the rate of learning as well as the level of recall.

The SWM task requires retention and manipulation of visuo-spatial information. This self-ordered test provides a measure of strategy as well as working memory errors. The test involves a number of colored squares (boxes) shown on the screen which require a selection strategy to fill an empty column. The test takes about 4 minutes to complete. Outcome measures of the SWM include errors and strategy. The computerized Corsi Block will be the version of the SWM task used in this study.

Change from baseline in the Digit Symbol Substitution Test (DSST). A computerized test with the task is to match digits with symbols from encoding list. The number of digits correctly encoded within 3 minutes is the performance measure.