2.3. Procedure
Non-patients were recruited via billing boards in the surroundings of Maastricht University, and advertisement in the local newspaper. They were informed about the study by an information letter, and enrolled by email. Non-patients were first interviewed with SCID-I and SCID-II and they filled in the RPQ, using an online environment for questionnaires (EMIUM). Clinical patients who met the inclusion criteria were contacted by the experimenter. The SCID-I and SCID-II interviews had already been administered during intake at the clinics. If patients were willing to participate, they either received an email with a personal code in order to complete the RPQ online, or were tested in the clinic where they were being treated. Participants were debriefed and received a small financial compensation or university participation credits. All participants signed informed consent, the study was approved by the Ethics Committee Psychology of the Faculty of Psychology and Neuroscience, Maastricht University and it conforms to the Code of Ethics of the World Medical Association (Declaration of Helsinki).