Source Paper
Dopaminergic foundations of schizotypy as measured by the German version of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE)—a suitable endophenotype of schizophrenia
Phillip Grant, Yvonne Kuepper, Eva A. Mueller, Catrin Wielpuetz, Oliver Mason et al.
Frontiers in Human Neuroscience • 2013
O-LIFE Questionnaire Administration
Objective: Test-theoretical analysis of the German version of the O-LIFE inventory to assess personality traits and screen for somatic, psychological health, drug use, and medication status
Protocol Steps
Participant recruitment for main sample
Email invitations sent to all members (students, fellows, administrative/technical employees) of Justus-Liebig-University (JLU) Giessen, oral invitations during lectures at JLU and THM (Technische Hochschule Mittelhessen), and personal contact invitations from Erftgymnasium Bergheim
Note: Invitations contained a link to the online version of the inventory
View evidence from paper
“email-invitation sent to all members (students, fellows, and administrative/technical employees) of Justus-Liebig-University (JLU), Giessen (Germany), through oral invitations during lectures by Phillip Grant at JLU and THM”
Online administration of main sample questionnaire
Participants access online-version via provided link and complete the German O-LIFE inventory along with screening questions regarding somatic and psychological health, drug use, and medication status
Note: Main sample consisted of 1228 participants (341 male, 887 female) with age ranging from 17 to 75 years
View evidence from paper
“The email/personal invitations contained a link to an online-version of the inventory programmed by the authors using the platform soscisurvey.de”
Re-test sample recruitment and administration
Three months after main sample, participants recruited using same methods. Online administration includes only the O-LIFE questionnaire (other questionnaires and items omitted) to reduce completion time and increase compliance
Note: Re-test sample: 245 participants (45 male, 200 female) with age range 17-58 years (M=25.83, SD=8.6)
View evidence from paper
“The sample for the re-test of the O-LIFE was acquired 3 months later in the same fashion as the main sample, whereby in this case all other questionnaires and items except the O-LIFE were omitted”
Genetic associations sample recruitment
Participants recruited from Giessen Gene Brain Behaviour Project (GGBBP) at Department of Personality Research and Individual Differences at JLU. Only participants who had signed consent form within 5 years prior to data acquisition were contacted
Note: Approximately 290 participants acquired from GGBBP (288 completed: 91 male, 197 female, age 18-51 years, M=22.9, SD=4). High rate of unreturned invitations noted
View evidence from paper
“The sample for genetic associations was acquired through the Giessen Gene Brain Behaviour Project (GGBBP) of the Department of Personality Research and Individual Differences at JLU”
Online administration of genetic associations sample
Participants from GGBBP complete O-LIFE questionnaire online via soscisurvey.de platform
Note: This sample had access to existing personality inventory data and polymorphism data from GGBBP database
View evidence from paper
“The GGBBP contains ca. 1800 datasets of participants including various personality inventories and data on several polymorphisms”