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WithdrawnNCT05180149PDUUpdated Apr 29, 2022

Personality and Drug Use (PDU)

An observational study in Personality, sponsored by Quantified Citizen Technologies Inc.. Withdrawn. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2022-04-29.

Sponsored by Quantified Citizen Technologies Inc. · Observational

Why this study was withdrawn
The sponsor of the study has changed. The study will be released, managed and registered by another institution who will be acting as a responsible party.
Study type
Observational
Model
Cohort
Time perspective
Retrospective
Enrollment
0
Ages
18 Years and older
Sex
All
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Study summary

The study aims to assess whether the use of drugs relates to personality ratings. Specifically, we plan to investigate if people with different histories of substance use differentiate on personality assessments (current and past).

Read the detailed description

The study aims to assess the association between the use of various substances (including psychedelic and non-psychedelic drugs) and personality profiles. Specifically, the association between past drug usage and personality profiles will be investigated. As psychedelics were found to influence changes in personality over time, the present study aims to measure both the current personality profile (via the Big Five Inventory-44 (BFI)) and perceived retrospective changes in personality (via a self-constructed Retrospective Personality Scale (RPS)). To our knowledge, no study has explored the diversity of substance use histories in relation to individual current and retrospective personality traits and aggregate personality profiles.

This project aims to survey a large number of participants from all around the world, using a mobile app-based survey. The remote character of the study will increase its accessibility and diversity, which are common shortcomings in the psychedelic line of research. Additionally, a remote, anonymous study setup with no face-to-face interactions might help overcome any potential concerns participants may have regarding the sharing of sensitive information (e.g., reports on illicit substance use).

To increase scientific transparency and for educational purposes, the study team plans to share results summaries (comparisons of personalized results with the aggregated ones among participants sharing similar characteristics e.g., age, substance use history), which might be an additional motivating factor for study completion. Lastly, given that drug use in the natural environment (excluding laboratory/experimental setting) is characterized by large substance diversity and poly-drug use, we aim for a large sample size (with a minimum of 36 subjects per substance(s) category) to perform subgroup analyses. Therefore, this large-scale, low-budget, naturalistic, retrospective, observational study aims to shed light on the aforementioned gap in the literature and to lay a foundation of evidence for further (observational and experimental) research within the field.

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Conditions studied

  • Personality

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Keywords

  • Personality
  • Substance Use
  • Psychedelics
  • Drugs
  • Changes in Personality
03

In context

Personality Disorders

336 studies on the registry are indexed under Personality Disorders; 48 are open to participants now.

Browse Personality Disorders studies →

Lead sponsor

This is the only study on the registry with Quantified Citizen Technologies Inc. as lead sponsor.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

Adults (age of 18 or above) of full mental and legal capacities.

Inclusion criteria

  • 18 years of age or older
  • full legal and mental capacity
  • access to a smartphone (iOS and Android) with internet

Exclusion criteria

Exclusion Criteria:

  • not fluent in English
  • not able to read
05

Study design

Observational model
Cohort
Time perspective
Retrospective
Enrollment
0 participants (actual)
Patient registry
No

Groups and cohorts

  • Psychedelics-only Group

    A group of participants who reported using in their past psychedelic substances only (both classical and non-classical psychedelics are included). Specifically, in the current study this group included reports on the following substances: Psilocybin (magic mushrooms, truffles) LSD (acid) Mescaline (peyote, san pedro) Dimethyltryptamine (DMT) Ayahuasca 5-MeO-DMT 3-MMC Ibogaine Salvia Phenethylamines (2C family)

  • Stimulants-only Group

    A group of participants who reported using in their past drugs identified as stimulating compounds only (both recreational and prescribed usages are included). Stimulating compounds are considered, in the context of the current study, substances that increase the overall activity of the central nervous system. Specifically, in the current study this group included reports on the following substances: Cocaine Crack Amphetamines Methamphetamines Prescription stimulants (e.g., Adderall, Ritalin, Concerta)

  • Depressants-only Group

    A group of participants who reported using in their past drugs identified as depressing compounds only (both recreational and prescribed usages are included). Depressing compounds are considered, in the context of the current study, substances that decrease the overall activity of the central nervous system. Specifically, in the current study this group included reports on the following substances: Benzodiazepines Opiates (recreational use of heroin, opium, hydrocodone, oxycodone, oxymorphone, codeine, fentanyl) Prescription opioids

  • Cannabinoids Group

    A group of participants who reported using in their past cannabinoids compounds only (both recreational and prescribed usages are included). Specifically, in the current study this group included reports on the following substances: THC (cannabis, marijuana) CBD Medical Cannabis (both THC and CBD)

  • Psychedelic and Non-psychedelic Substances Group

    A group of participants who reported using in their past drugs identified as psychedelics and stimulants and/or depressants (both recreational and prescribed usages are included). In this group participants will be included who reported using at least one non-psychedelic drug additionally to a psychedelic one. Specifically, the following options were provided: 1. Psychedelic compounds: Psilocybin (magic mushrooms, truffles) LSD (acid) Mescaline (peyote, san pedro) Dimethyltryptamine (DMT) Ayahuasca 5-MeO-DMT 3-MMC Ibogaine Salvia Phenethylamines (2C family) 2. Non-psychedelic compounds: THC (cannabis, marijuana) Medical Cannabis (both THC and CBD) CBD MDMA (ecstasy) Ketamine Cocaine Crack Amphetamines Methamphetamines Prescription stimulants (e.g., Adderall, Ritalin, Concerta) Benzodiazepines Opiates (e.g., heroin, opium, hydrocodone, oxycodone, oxymorphone, codeine, fentanyl) Prescription opioids

  • Substance-naive Group

    A group of participants who reported no past experience with any of the substances listed in the current study nor reported using other substances (excluding alcohol and nicotine). Participants will be assigned to this group if and only if they choose the "None of the above" option from the Substance Use Survey (item 1).

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What researchers measure

Primary outcomes

  1. Current Personality Profile

    Raw scores on each of dimensions of the Big Five Inventory

    Time frame: Single baseline measurement

Secondary outcomes

  1. Changes in Personality Profile

    Raw scores on the positive and negative dimensions of the self-constructed (for the study needs) Retrospective Personality Scale

    Time frame: Single baseline measurement

07

Study locations

No study locations are listed for this record.

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References and documents

Publications

  • Kiraga MK, Mason NL, Uthaug MV, van Oorsouw KIM, Toennes SW, Ramaekers JG, Kuypers KPC. Persisting Effects of Ayahuasca on Empathy, Creative Thinking, Decentering, Personality, and Well-Being. Front Pharmacol. 2021 Oct 1;12:721537. doi: 10.3389/fphar.2021.721537. eCollection 2021. PubMed 34658861 ↗
  • Bouso JC, Gonzalez D, Fondevila S, Cutchet M, Fernandez X, Ribeiro Barbosa PC, Alcazar-Corcoles MA, Araujo WS, Barbanoj MJ, Fabregas JM, Riba J. Personality, psychopathology, life attitudes and neuropsychological performance among ritual users of Ayahuasca: a longitudinal study. PLoS One. 2012;7(8):e42421. doi: 10.1371/journal.pone.0042421. Epub 2012 Aug 8. PubMed 22905130 ↗
  • Bouso JC, Palhano-Fontes F, Rodriguez-Fornells A, Ribeiro S, Sanches R, Crippa JA, Hallak JE, de Araujo DB, Riba J. Long-term use of psychedelic drugs is associated with differences in brain structure and personality in humans. Eur Neuropsychopharmacol. 2015 Apr;25(4):483-92. doi: 10.1016/j.euroneuro.2015.01.008. Epub 2015 Jan 16. PubMed 25637267 ↗
  • Williams MT, Davis AK, Xin Y, Sepeda ND, Grigas PC, Sinnott S, Haeny AM. People of color in North America report improvements in racial trauma and mental health symptoms following psychedelic experiences. Drugs (Abingdon Engl). 2021;28(3):215-226. doi: 10.1080/09687637.2020.1854688. Epub 2020 Dec 10. PubMed 34349358 ↗
  • Martins SS, Sampson L, Cerda M, Galea S. Worldwide Prevalence and Trends in Unintentional Drug Overdose: A Systematic Review of the Literature. Am J Public Health. 2015 Nov;105(11):e29-49. doi: 10.2105/AJPH.2015.302843. PubMed 26451760 ↗
  • Harm reduction: An approach to reducing risky health behaviours in adolescents. Paediatr Child Health. 2008 Jan;13(1):53-60. doi: 10.1093/pch/13.1.53. No abstract available. PubMed 19119355 ↗

Individual participant data

Plan to share: Yes — The study will be pre-registered on the Open Science platform, where study details will be shared and regularly updated. This will be an open access project, meaning that all collected data and data analysis will be made available for all interested parties (via OSF platform). Additionally, we will share the individual summary reports with all participants who completed the study. The report will be accessible via a mobile app used to collect the study data.

Supporting information: Study protocol, Sap, Icf, Csr, Analytic code

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 29, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT05180149
Lead sponsor
Quantified Citizen Technologies Inc.
Collaborators
Maastricht University, Psychedelic Data Society
Responsible party
Maggie Kiraga (Research Associate, Maastricht University) — Principal investigator
First posted
Jan 6, 2022
Start date
Apr 2022 (estimated)
Primary completion
Apr 2023 (estimated)
Completion
Apr 2023 (estimated)
Last update
Apr 29, 2022

Study contacts

Kim PC Kuypers, PhD
principal investigator · Maastricht University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is withdrawn, as verified in Apr 2022. You cannot join it, but the record below documents what was studied.

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