Dopamine, stress reactivity & hearing impairment.

Background of the study:

It has been suggested that the experience of social defeat / social exclusion is a major risk factor for psychosis. Such experience may account for a large portion of the increased psychosis risk under hearing impaired individuals, a group which has trouble participating in hearing society and does not identify with the signing Deaf. Research with the Experience Sampling Method has shown that psychosis patients and their siblings react more strongly to daily life stress. Increased stress reactivity meets the criteria for an endophenotype for psychosis. We hypothesize that sensitisation of the stress system through chronic exposure to
social stress is an important mechanism leading to increased psychosis risk in the hard of hearing. If this is the case, healthy hearing impaired individuals should show increased stress reactivity and this result should be related to dopaminergic activity. Understanding the pathogenic mechanism would allow for the development of preventive interventions to improve minority mental health.



Objective of the study:

To examine whether hearing impaired young adults are sensitised to social stress and whether this related to dopaminergic activity.



Study design:

Observational, 2 groups (normal hearing / hearing impaired).



Study population:

30 healthy human volunteers, 18-30 years old. Participated in study NL24257.018.08. Bilateral hearing loss > 60 dB (hearing impaired) or < 20 dB (normal hearing).



Primary study parameters/outcome of the study:

Relationship between hearing impairment and reactivity (changes in affect and psychotic symptoms) to self-reported stress in
daily life, assessed using the Experience Sampling Method (ESM).



Secundary study parameters/outcome of the study:

1. Association between dopamine release and stress reactivity;

2. Group level differences in reactivity to other forms of (event related, activity) stress.



Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

Briefing, debriefing and all tests and questionnaires can be done at home in 3 hours. ESM is integrated in daily life and takes about 3 hours over a period of eight days. Time investment (6.5 hrs) will be compensated with a monetary reward. Participants
will not benefit directly, but will contribute to better prevention of psychotic disorder. No health risks are involved in the study.

Hard of hearing individuals are selected as proxy for social exclusion because of reports of elevated psychosis risk in that group.

We hypothesize that sensitisation of the stress system through chronic exposure to social stress is an important mechanism leading to increased psychosis risk in the hard of hearing. If this is the case, healthy hearing impaired individuals should show increased stress reactivity and this result should be related to dopaminergic activity.

1. Briefing session;

2. 8 days of Experience sampling;

3. Debriefing session.

N/A