This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Efficacy of Psilocybin in OCD: a Double-Blind, Placebo-Controlled Study. (NCT03356483), a randomized phase 1 study. The primary outcome is Changes in Severity of OCD Symptoms, Which Will be Measured by The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The Primary Outcome Measure Will be Collected at Baseline and 48 Hours, Assessing Change From Baseline at 48 Hours..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03356483 |
| Phase | Phase 1 |
| Condition | Obsessive-Compulsive Disorder |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 28 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Yale University |
| Results posted | Yes |
2. Clinical Question
Population
People with obsessive-compulsive disorder (OCD). The registry lists an enrollment of 28. The characteristics of participants, including diagnostic criteria and baseline symptom severity, are not reported in the registry record.
Intervention
Oral psilocybin, listed as 0.25mg/kg. The study description says it investigates effects on OCD symptoms and explores neural correlates that may mediate purported therapeutic effects.
Comparator
Niacin, listed as 250mg. The title calls the study placebo-controlled, while the intervention listing identifies niacin as the comparator. Details about how the comparator was selected or intended to function are not reported in the registry record.
Primary question
How did OCD symptom severity, measured using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), change after treatment? The primary outcome title specifies change from baseline at 48 hours, while the outcome timeframe also lists later follow-up. A primary comparison estimate and its uncertainty are not reported in the registry record.
The clinical question is framed around symptom change rather than a binary outcome. The Y-BOCS assesses types and severity of obsessions and compulsions over the past seven days. The record also lists changes in functional impairment, measured by the Sheehan Disability Scale, and depression symptoms, measured by the Montgomery-Asberg Depression Scale, as secondary outcomes. Those measures broaden the clinical description but do not replace the stated primary outcome.
The registry describes the study as preliminary and exploratory. The neural-correlate aim is part of the study description, but the specific neural measures and their results are not reported in the registry record. The available information therefore identifies the question and intended measures, but does not establish the magnitude or precision of any clinical outcome difference.
3. Trial Design
The record identifies a Phase 1, randomized, quadruple-masked, parallel-group study sponsored by Yale University. Its title describes a double-blind, placebo-controlled study, while the registry's masking field says quadruple. These descriptions are both retained in the record; further details about who was masked, how masking was maintained, or whether it was assessed are not reported in the registry record.
The listed groups are Psilocybin and Niacin, with doses of 0.25mg/kg and 250mg respectively. The record lists an enrollment of 28 and a completed status. The study dates listed are 2018-11-13 for start and 2024-07-25 for primary completion. The record does not say how many participants were randomized, received treatment, completed the primary assessment, or were included in each outcome analysis.
Parallel-group design means that participants are assigned to a group and outcomes can be compared across groups. Random allocation can reduce systematic differences at the start, on average, but it does not guarantee that the groups are alike in a particular trial. Baseline characteristics and details of the allocation process are not reported in the registry record, so the degree of baseline comparability cannot be assessed from these details.
The registry also lists a Psilocybin-Unblinded group in its safety information. Its relationship to the randomized Psilocybin group is not described, so it should not be assumed to represent a separate randomized arm or added to the enrollment count. The purpose, timing, and participant overlap for this entry are not reported in the registry record. The record lists 36 outcome measures and 2 analyses, but does not identify the specific analyses or link them to particular outcomes.
The study is described as preliminary and includes exploratory investigation of neural correlates. The registry information does not report a protocol, a sample-size justification, or the planned analysis model. Those omissions limit how fully the design and the intended confirmatory or exploratory roles of different analyses can be reconstructed.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Psilocybin | Niacin |
|---|---|---|
| STARTED | 14 | 14 |
| Completed 48 hour follow up | 13 | 14 |
| Completed 1 week follow up | 13 | 14 |
| Received Psilocybin unblinded | 0 | 14 |
| COMPLETED | 12 | 14 |
| NOT COMPLETED | 2 | 0 |
Analysis population for the primary outcome, as defined in the registry: Data presented here is from participants that completed each time point. Weeks 2, 4, 8, and 12 only collected from Psilocybin arm
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Psilocybin | Niacin | Total |
|---|---|---|---|---|
| Participants analysed | 14 | 14 | 28 | |
| Age, Continuous | years | 35.5 (SD 11.78) | 32.93 (SD 12.44) | 34.22 (SD 12.05) |
| Sex/Gender, Customized: Female | Participants | 6 | 8 | 14 |
| Sex/Gender, Customized: Male | Participants | 7 | 6 | 13 |
| Sex/Gender, Customized: Trans/Non-binary | Participants | 1 | 0 | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 | 1 | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 14 | 13 | 27 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 1 | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): White | Participants | 14 | 13 | 27 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 14 | 14 | 28 |
| Education: High School or less | Participants | 0 | 1 | 1 |
| Education: Some college | Participants | 3 | 4 | 7 |
| Education: College graduate | Participants | 7 | 8 | 15 |
| Education: Postgraduate | Participants | 4 | 1 | 5 |
| Obsessive Compulsive Disorder (OCD) Severity | score on a scale | 26.36 (SD 4.63) | 27.21 (SD 3.31) | 26.79 (SD 3.98) |
| Current Medication: None | Participants | 8 | 9 | 17 |
| Current Medication: Required washout | Participants | 6 | 5 | 11 |
| Prior Psilocybin Exposure | Participants | 4 | 2 | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Changes in Severity of OCD Symptoms, Which Will be Measured by The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The Primary Outcome Measure Will be Collected at Baseline and 48 Hours, Assessing Change From Baseline at 48 Hours., measured over Baseline, weeks: 1, 2, 4, 12 post-drug.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | score on a scale |
| Endpoint classification | Continuous Endpoint |
The primary outcome is change in severity of OCD symptoms measured by the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The record describes the measure as covering symptoms over the past seven days. It has a symptom checklist and a severity scale; prominent obsessions and compulsions are identified and then rated. The severity scale has 11 items, of which 3 are not included in the total score. Items use a 0 to 4 severity scale, and total scores range from 0 to 40, with higher scores indicating greater OCD symptom severity.
A symptom scale can retain more information than a simple response category because it records degrees of severity. Change from baseline can describe whether scores moved over time, while a comparison between randomized groups can help distinguish treatment-associated change from change that may also occur under the comparator. These are general features of continuous clinical outcomes; the registry does not report the result of such a comparison.
The primary outcome title specifies measurement at baseline and change from baseline at 48 hours. The timeframe field also lists baseline and follow-up at weeks 1, 2, 4, and 12, while the population description says that weeks 2, 4, 8, and 12 were collected only from the Psilocybin arm. This difference in timing descriptions makes it important not to treat all listed follow-ups as a direct randomized comparison. The intended primary time point beyond the stated 48-hour assessment is not clarified in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies the clinical outcome and trial design, but the primary outcome results are not reported in the registry record. In particular, the record does not state group means, standard deviations, changes from baseline, a between-group estimate, a confidence interval, or a p-value for the Y-BOCS outcome. The direction, magnitude, and precision of the primary comparison therefore cannot be described from these registry entries.
For a continuous outcome, a group mean describes the average score in that group, and a standard deviation describes how spread out individual scores are around that average. A change score describes how a measure differs from baseline at a later assessment. To understand a randomized comparison, readers generally need the estimated difference in change between groups, together with its uncertainty. Separate within-group changes alone would not establish that the groups changed differently.
In general, a confidence interval gives a range of values compatible with the data and the analysis assumptions at a stated confidence level. A narrow interval indicates greater statistical precision than a wide interval, though precision alone does not establish clinical importance. No confidence interval or effect estimate for the primary outcome is reported in the registry record, so neither precision nor clinical importance can be evaluated.
The record lists a primary assessment at 48 hours and longer follow-up time points, but does not report Y-BOCS values at any time point. It also says that some later time points were collected only in the Psilocybin arm. Without outcome values and clarity about which time point was analyzed for the primary comparison, the listed time frame cannot be converted into a conclusion about comparative change.
The secondary outcomes are functional impairment measured by the Sheehan Disability Scale and depression symptoms measured by the Montgomery-Asberg Depression Scale. Their results are not reported in the registry record. The study description also mentions neural correlates, but does not report neural outcome findings. Thus, the record supports a description of what investigators intended to measure, not a conclusion about observed efficacy or mechanism.
The listed enrollment of 28 is not itself evidence about the size or reliability of an outcome effect. The number randomized, the number with observed data at each time point, and the number analyzed are not reported in the registry record. This matters because precision depends on analyzable information, not solely on the enrollment entry. The posted safety counts are described separately and cannot substitute for missing clinical outcome estimates.
In general, a p-value measures how incompatible data are with a specified null model under the analysis assumptions; it does not quantify the size or clinical importance of an effect. No primary p-value is reported in the registry record. There is consequently no statistical significance claim to interpret, and no basis in this record for saying that one group had greater or lesser symptom improvement.
9. Statistical Methods Explained
The registry characterizes the primary measure as continuous and reports means and standard deviations as the outcome parameter and dispersion. That identifies a natural descriptive summary, but not the inferential procedure used to compare groups. The analysis model, covariates, handling of baseline scores, and method for calculating uncertainty are not reported in the registry record.
What does a mean and standard deviation describe?
In general, a mean is the arithmetic average of observed scores. A standard deviation describes how much scores vary around that average. Together, they give a compact account of a continuous measure, but do not show the full distribution or reveal whether observations are missing. The registry does not report the group means or standard deviations for the primary outcome, so these summaries cannot be interpreted for this trial.
For change from baseline, a key distinction is between change within each group and the difference in change between groups. A group can improve over time for reasons that are not specific to its assigned intervention. In a randomized trial, the comparative estimate is usually the relevant quantity for assessing whether the groups experienced different changes. The registry record names change from baseline as the primary outcome but does not report a comparative estimate or explain how change was calculated.
Why does the analysis time point matter?
The primary outcome title specifies a baseline measure and an assessment at 48 hours. The timeframe field lists additional assessments, and the population description notes that weeks 2, 4, 8, and 12 were collected only from the Psilocybin arm. A comparison at a time point measured in both randomized groups has a different interpretation from a follow-up available in only one group. The analysis time point, and how the differing descriptions are reconciled, are not reported in the registry record.
Repeated measurements can be analyzed in different ways. General approaches may compare groups at a selected time point, analyze change scores, or model measurements across time. These approaches rely on different assumptions and answer somewhat different questions. The registry does not identify which approach was used, whether all follow-up visits were included in one model, or whether the primary analysis was limited to the 48-hour assessment. No statistical model should therefore be attributed to the trial based on the endpoint description alone.
What do uncertainty and significance tests contribute?
In general, a confidence interval communicates the range and precision of an estimated group difference under the analysis assumptions. A hypothesis test provides a measure of compatibility between the observed data and a null hypothesis. Neither is a substitute for the estimated effect itself, and neither alone indicates whether a difference is clinically important. The registry does not report the primary estimate, interval, or test result.
The record states that a planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with effects defined as fractions of the observed effect. This is described as a planning illustration computed from an observed effect, not as the trial's own design. The numerical planning estimates are not reported in the registry record. Such illustrations are not observed power and should not be interpreted as evidence that the trial had a particular probability of detecting an effect. The trial's own sample-size justification is not reported in the registry record.
What can be said about the analysis population?
In general, an analysis population states which participants contribute to an estimate, such as everyone randomized or only those with an available measurement. The registry's primary outcome description says that data are from participants who completed each time point. This indicates that the described data are restricted by time-point completion, but does not specify the number included or whether other analysis populations were used. The handling of participants with incomplete measurements is not reported in the registry record.
For repeated measurements, missing observations can affect both the amount of information and the interpretation of the observed cases. If completion is related to symptoms or treatment experience, results among completers may differ from results for all randomized participants. This is a general concern, not a finding about why participants did or did not complete assessments in this study. Imputation, sensitivity analyses, and assumptions about missingness are not reported in the registry record.
How should multiple outcomes be considered?
The record lists 36 outcome measures and 2 analyses, along with primary and secondary outcomes. When several outcomes or time points are examined, the chance of at least one apparently unusual finding can increase if many tests are considered together. General methods for addressing this include designating a primary outcome in advance and adjusting for multiple comparisons when appropriate. The registry record does not report a multiplicity strategy, an analysis hierarchy, or how the 2 listed analyses relate to the outcomes.
The endpoint is a continuous score, so concepts such as over-dispersion for count outcomes are not indicated by the recorded outcome type. In general, over-dispersion matters when count data vary more than a chosen count model expects; it is not a reason to alter interpretation of the Y-BOCS mean solely on the basis of this record. The main statistical limitation is not evidence of a particular model problem, but the absence of outcome estimates and details of the analysis used.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 36 outcome measures and 2 analyses. It identifies the Y-BOCS change measure as primary and lists changes in functional impairment and depression symptoms as secondary outcomes. The study description also refers to exploratory investigation of neural correlates. The record does not state how these measures were prioritized beyond the primary and secondary labels, how the 2 analyses correspond to them, or whether any adjustment for multiple testing was planned.
In general, examining many outcomes and time points creates multiple opportunities for a result to appear noteworthy by chance. A prespecified primary outcome and time point can help focus interpretation, while a declared multiplicity procedure can address the error rate across a family of tests. Neither a procedure nor a confirmatory analysis hierarchy is reported in the registry record. This makes it impossible to determine whether any hypothetical secondary finding would be exploratory or adjusted for the number of comparisons.
For missing data, the primary outcome description says data are presented from participants who completed each time point. It does not report how many completed each assessment, why data might be absent, whether any values were imputed, or whether sensitivity analyses were conducted. General statistical concern arises when missingness may depend on participant characteristics or outcomes: a completer-only summary may not represent all randomized participants. The record does not establish whether that concern affected this trial.
The analysis population is not otherwise specified. In particular, the record does not say whether the main analysis included all randomized participants, only those who received treatment, or another defined group. It also does not explain how participants were handled if they discontinued or had incomplete follow-up. These details are needed to judge which population the reported estimates would describe; the estimates themselves are not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Psilocybin | 1 | 14 | 7.1% |
| Niacin | 0 | 14 | 0.0% |
| Psilocybin-Unblinded | 0 | 14 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Psilocybin | 0 of 14 |
| Niacin | 0 of 14 |
| Psilocybin-Unblinded | 0 of 14 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Psilocybin | 12 of 14 |
| Niacin | 6 of 14 |
| Psilocybin-Unblinded | 10 of 14 |
Most frequent serious adverse event terms
| Event term | Organ system | Psilocybin | Niacin | Psilocybin-Unblinded |
|---|---|---|---|---|
| Suicidal ideation | Psychiatric disorders | 1 of 14 | 0 of 14 | 0 of 14 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Psilocybin | Niacin | Psilocybin-Unblinded |
|---|---|---|---|---|
| Dizziness | Nervous system disorders | 3 of 14 | 2 of 14 | 6 of 14 |
| Nausea | Gastrointestinal disorders | 5 of 14 | 2 of 14 | 4 of 14 |
| Headache | Nervous system disorders | 4 of 14 | 2 of 14 | 4 of 14 |
| Paresthesia | Nervous system disorders | 4 of 14 | 2 of 14 | 2 of 14 |
| Visual perceptual changes | Psychiatric disorders | 5 of 14 | 0 of 14 | 0 of 14 |
| Flushing | Cardiac disorders | 1 of 14 | 3 of 14 | 0 of 14 |
| Anxiety | Psychiatric disorders | 3 of 14 | 0 of 14 | 0 of 14 |
| Mood lability | Psychiatric disorders | 1 of 14 | 0 of 14 | 2 of 14 |
| Hypertension | Cardiac disorders | 1 of 14 | 0 of 14 | 0 of 14 |
| Suicidal ideation | Psychiatric disorders | 1 of 14 | 0 of 14 | 0 of 14 |
Serious events with the highest arm-level rate: suicidal ideation (7.1%).
The registry safety entries list Psilocybin, Niacin, and Psilocybin-Unblinded. For the Psilocybin entry, 1 of 14 participants at risk is listed as having a serious adverse event; the Niacin and Psilocybin-Unblinded entries list 0 of 14. Deaths are listed as 0 in each entry. These are registry counts, not comparative effect estimates, and the relationship between the unblinded entry and the randomized groups is not reported in the registry record.
Suicidal ideation is the listed top serious-event term, at 7.1%. The record does not specify in this entry which group the term refers to or provide further event-level detail. It also does not report the timing, duration, severity beyond the serious-event classification, or outcome of the event.
Other adverse events are listed for 12 of 14 at risk in Psilocybin, 6 of 14 in Niacin, and 10 of 14 in Psilocybin-Unblinded. These counts should be read as affected participants in their respective entries, not as numbers of distinct events. The record does not clarify whether participants could appear in more than one category or how the unblinded group relates to the other entries. Serious and non-serious event counts do not, by themselves, show causation or establish a comparative safety difference.
12. What the Result Does, and Does Not, Mean
The record documents a randomized Phase 1 study designed to examine OCD symptom severity after psilocybin compared with niacin. It identifies the Y-BOCS as the primary measure and describes its scoring and follow-up plans. It also records secondary measures and safety counts. However, the primary outcome results are not reported in the registry record, so the clinical outcome question cannot be answered from these details.
That absence means the record does not establish the direction or size of a group difference, whether scores changed differently between groups, or how precisely any difference was estimated. It does not support a claim that psilocybin improved symptoms, failed to improve symptoms, or differed from niacin. The absence of a reported estimate is not evidence that the groups were the same; it means the comparative result is unavailable in the registry information.
The safety entries report affected-participant counts, including one serious adverse event in the Psilocybin entry and none in the Niacin or Psilocybin-Unblinded entries. Those counts can describe what the registry lists, but without event context and a clear explanation of group relationships, they do not establish that an event was caused by an intervention or permit a complete comparison of safety.
In general, a clinical interpretation needs more than a statistical test. It considers the size of an effect, its uncertainty, the outcome's meaning, and the design and analysis assumptions. The record does not report the primary effect estimate or its uncertainty, and it does not provide the analysis plan needed to evaluate those assumptions. A sample-size planning illustration, where available, is not a result and is not observed power.
The proper conclusion is limited: the registry describes a study intended to evaluate symptom change and exploratory neural correlates, but does not report the clinical outcome estimates required to judge those aims. This limitation applies to interpretation of the registry record, not necessarily to information that may exist elsewhere.
13. Why This Trial Matters Statistically
This study raises several statistical issues that are common in small, preliminary clinical trials. The randomized, parallel design provides a framework for comparing groups, while a continuous symptom scale can represent differences in severity rather than reducing responses to a simple yes-or-no outcome. For that framework to support interpretation, however, readers need group-specific summaries and a comparative estimate with uncertainty. Those primary results are not reported in the registry record.
Timing is especially important. The primary outcome title specifies change at 48 hours, while the listed timeframe includes later follow-up and the population description says several later assessments were collected only in the Psilocybin arm. A single arm's follow-up can describe its observed trajectory, but does not by itself provide a randomized comparison at those time points. The record does not clarify which time point defines the primary analysis beyond the stated 48-hour assessment.
Missing data and multiplicity also matter. The outcome description refers to participants who completed each time point, yet the number completing assessments and the missing-data approach are not reported. The registry lists 36 outcome measures, but does not specify a multiplicity strategy or explain the 2 analyses. Without those details, readers cannot fully assess selection, precision, or the role of exploratory findings.
The safety listing illustrates a separate interpretive challenge: it includes an unblinded Psilocybin entry alongside the named Psilocybin and Niacin groups. Without knowing how these entries relate, it is important not to treat them as independent arms or combine their counts. Overall, the statistical importance of this record lies in its clear statement of the intended clinical measure alongside substantial gaps in reported outcome estimates and analysis detail.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The registry does not report primary Y-BOCS results, including group summaries, change estimates, uncertainty intervals, or a test result. This is the central limitation for assessing the clinical question. The number randomized and the number contributing data at each time point are also not reported in the registry record, despite the listed enrollment of 28.
Outcome timing is not fully clear. The primary outcome title specifies baseline and 48 hours, while the timeframe lists baseline and weeks 1, 2, 4, and 12. A separate population description identifies weeks 2, 4, 8, and 12 as collected only from the Psilocybin arm. The record does not explain this difference or identify the analysis time point used for the primary comparison beyond the 48-hour wording.
The registry does not report diagnostic eligibility details, baseline participant characteristics, allocation procedures, analysis models, covariate adjustment, handling of missing outcomes, or the analysis population. The description of completed time points suggests that observed data were tied to completion, but does not establish what happened to participants with missing measurements. The record also lists 36 outcome measures and 2 analyses without reporting their relationship or a strategy for multiple comparisons.
Safety interpretation has additional limits because the Psilocybin-Unblinded entry is not explained. The record does not clarify whether its participants overlap with the other entries, why the group is listed, or how the serious-event term is assigned. These uncertainties preclude treating all entries as distinct groups or inferring causes from counts.
The sample-size justification for the trial is not reported in the registry record. The listed planning assumptions describe an illustration based on an observed effect, but do not supply a basis for reconstructing the trial's original design rationale. The study's preliminary and exploratory aims are noted, yet detailed neural measures and findings are not reported.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Efficacy of Psilocybin in OCD: a Double-Blind, Placebo-Controlled Study. — NCT03356483.
- Registry record last updated 2026-10-16; status last verified 2025-08.
- Results first posted 2026-10-16.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
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18. Record Summary
The record describes a completed, randomized, quadruple-masked Phase 1 parallel-group study sponsored by Yale University, with an enrollment of 28. The study compares psilocybin 0.25mg/kg with niacin 250mg in people with obsessive-compulsive disorder. Its primary outcome is change in OCD symptom severity measured by the Y-BOCS; secondary outcomes assess functional impairment and depression symptoms.
The registry lists an outcome timeframe that includes baseline and later follow-up, but the primary outcome title specifies a 48-hour assessment and the population description notes that some later time points were collected only in the Psilocybin arm. It lists 36 outcome measures and 2 analyses. Primary outcome estimates, analysis details, a multiplicity strategy, and the trial's own sample-size justification are not reported in the registry record.
Safety entries list one serious adverse event in the Psilocybin group and none in the Niacin or Psilocybin-Unblinded entries, with no deaths listed. The relationship of the unblinded entry to the other groups is not explained. Overall, the record describes the trial's aims, measures, and selected safety counts but does not report the results needed to estimate comparative clinical effects.