Personality and Drug Use (PDU)

• ClinicalTrials.gov Identifier: NCT05516823
• Recruitment Status: Not yet recruiting
• First Posted: August 26, 2022
• Last Update Posted: September 28, 2022
• Sponsor: Psychedelic Data Society
• Collaborators: Maastricht University; Quantified Citizen Technologies Inc.
• Information provided by (Responsible Party): Psychedelic Data Society

Study Description

Brief Summary:

This is an observational, naturalistic study that aims to assess whether people with different histories of recreational or therapeutic illicit substance use (or no history at all) will differ in terms of their personalities.

Condition or disease	Intervention/treatment
No Conditions Study Focus on Substance Use and Personality	Other: Usage of drugs

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 study will investigate if people with different histories of drug use differ in personality profiles. As psychedelics were found to influence changes in personality over time, the investigators sought 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 investigators' knowledge, no study has explored the diversity of substance use histories in relation to individual current and retrospective personality traits and aggregate personality profiles.

The investigators aim 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 and 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 (comparing personalized results with the aggregated results of participants with similar socio-demographic profiles), investigators plan to share personalized results summaries with participants of the study, which might be an additional motivating factor for study completion. In conclusion, this large-scale, low-budget, naturalistic, retrospective, observational study aims to shed light on the aforementioned gap in the literature and lay a foundation of evidence for further research.

Study Design

• Study Type: Observational
• Estimated Enrollment: 1000 participants
• Observational Model: Case-Control
• Time Perspective: Retrospective
• Official Title: Personality and Drug Use
• Estimated Study Start Date: November 2022
• Estimated Primary Completion Date: November 2023
• Estimated Study Completion Date: November 2023

Groups and Cohorts

Group/Cohort	Intervention/treatment
Group: 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)	Other: Usage of drugs; Self-reported past usage of drugs belonging to different chemical groups.
Group: 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)	Other: Usage of drugs; Self-reported past usage of drugs belonging to different chemical groups.
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	Other: Usage of drugs; Self-reported past usage of drugs belonging to different chemical groups.
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)	Other: Usage of drugs; Self-reported past usage of drugs belonging to different chemical groups.
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: 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) Non-psychedelic compounds: THC (cannabis, marijuana) CBD Medical Cannabis (both THC and 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	Other: Usage of drugs; Self-reported past usage of drugs belonging to different chemical groups.
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).

Outcome Measures

Primary Outcome Measures :

1. Change in scores on Big Five Inventory (BFI-44) [ Time Frame: Measured twice: once referring to participants' personality from a period of their youth (18-21 years old) and the second time: the current moment, how they perceived their personality in general terms. ]
   The study will collect measures of past (youth) and current BFI scores. A separate score will be reported for each of the 5 personality traits measured by the inventory. Each score is computed by averaging the items associated with a given domain. Scores for each domain vary from 1 to 5, with higher scores meaning that a given trait is more present and noticeable in personality of the person that provided the answers.

Secondary Outcome Measures :

1. Change in scores on Retrospective Personality Scale (RPS) [ Time Frame: Measured twice: once referring to participants' personality from a period of their youth (18-21 years old) and the second time: the current moment, how they perceived their personality in general terms. ]
   The study will collect measures of past (youth) and current RPS scores. A separate score will be reported for each of the 2 personality domains: positive and negative. Each of the 20 items is scored on a 3-point scale, using the following encoding: -1 (=Less), (=Without change), 1 (=More). Mean scores of 10 items for each of the domains (positive and negative) form the total score. Score Interpretation: For the positive domain, the mean score of 0 indicates no changes in personality, whereas the positive mean score (larger than 0) indicates positive changes in personality and scores below 0 point out negative changes. The reverse interpretation is true for the negative domain, with a mean score of 0 indicating no changes.

Eligibility Criteria

• Ages Eligible for Study: 18 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Sampling Method: Non-Probability Sample

Study Population

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

Criteria

Inclusion Criteria:

• 18 years of age or older
• full legal and mental capacity
• access to a smartphone with internet to fill in the study measures (available for iOS and Android)

Exclusion Criteria:

• lack of proficiency in English
• visual impairments (not able to use mobile devices)
• illiteracy

Contacts and Locations

Contacts

Contact: Maggie K Kiraga, MSc; 4373249251 ext 001; maggie@quantifiedcitizen.com

Contact: Kim PC Kuypers, PhD; fpn-pim_P138@maastrichtuniversity.nl

Sponsors and Collaborators

Psychedelic Data Society

Maastricht University

Quantified Citizen Technologies Inc.

Investigators

• Principal Investigator: Kim PC Kuypers, PhD; Maastricht University

More Information

• Responsible Party: Psychedelic Data Society
• ClinicalTrials.gov Identifier: NCT05516823
• Other Study ID Numbers: 21017 Personality and Drug Use
• First Posted: August 26, 2022
• Last Update Posted: September 28, 2022
• Last Verified: August 2022

Individual Participant Data (IPD) Sharing Statement:

• Plan to Share IPD: Yes
• Plan Description: 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 Materials: Study Protocol; Statistical Analysis Plan (SAP); Informed Consent Form (ICF); Clinical Study Report (CSR); Analytic Code
• Time Frame: The raw data and clinical study report will be made available within 12 months from the end date of data collection.
• Access Criteria: Open access
• URL: https://osf.io/r3sut

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Psychedelic Data Society:

personality; substance use; psychedelics; drugs

Additional relevant MeSH terms:

Substance-Related Disorders; Personality Disorders; Chemically-Induced Disorders; Mental Disorders