Stress reactivity in psychosis: the association between traumatic events, genetic vulnerability and psychotic reactivity to stress

Daily life events can be experienced as stressful and subsequently induce
subtle fluctuations in psychotic experiences, in both patients diagnosed with a
psychotic disorder and healthy individuals. These psychotic experiences,
induced by daily life stress, also have their effect on the human body; the
production of stress-hormones such as cortisol increases during these psychotic
experiences. Previous work has demonstrated that certain environmental factors
as well as genetic vulnerability to develop a psychosis are associated with the
amount of psychotic experienced induced by daily life stress. In this study, it
will be investigated for the first time how one particular environmental factor
which seems to be particularly involved in psychosis, namely the experience of
traumatic events, in combination with a genetic vulnerability are associated
with each other and affect the fluctuation of psychotic experiences induced by
daily life stress. Furthermore, it will be investigated how this environmental
factor, in combination with a genetic vulnerability, affect the production of
cortisol throughout the day

The aim of this study is the investigate genetic and environmental factors
which make a person vulnerable to develop a pychosis and (in patients) affect
the progression of a psychosis. A second objective is to investigate the
effects of genetic and environmental factors on the human body, in the form of
cortisol.
As psychotic experiences of both patients and non-patients fluctuate in the
course of the day, the amount of psychotic experiences will be measured
multiple times per day, as will cortisol.

This is an observational study, consisting of three meetings and a PsyMate
week. During the first meeting, the participants will be extensively informed
about the study. After the participant has had time to consider taking part in
the study and has decided to take part in the study, a second meeting will be
planned. During this second meeting, the participant will sign the informed
consent form. Next, he/she will receive instructions to operate the PsyMate.
Additionally, a number of questionnaires and short interviews will be completed.
After the second meeting, a week of PsyMate measurements follows. During this
week, the participants will carry the PsyMate, a small device, with them for 6
days. During these 6 days, on random moments will emit a signal. When the
participants hears this signal, he/she will in fill a short questionnaire
(approx. 3 minutes) en will produce a saliva sample (to assess cortisol). When
the participants wakes up in the morning and before going to sleep in the
evening, the participant will fill in an addtional very brief questionnaire (<
1 minute). After these 6 days a third meeting will be planned. In this meeting,
the participant will be asked how he/she experienced last week. The PsyMate and
saliva samples will be collected. Furthermore, remaining questionnaires and
interviews will be completely. Lastly, the participants will give a saliva
sample for DNA. At the end of this meeting the participants will receive a
reimbursement for participating in the study

Participation in this study will take approximately 6 hours, for which
participants will be reimbursed accordingly. As none of the questionnaires,
interviewsa and PsyMate questionnaire create any risk, participation is
virtually free of any risks. There was no risk in participating in previous
daily life studies (identical to this study).