To test the following hypotheses:1. The baseline [123I]IBZM binding potential ([123I]IBZM-BP) in the ventral striatum is smaller in patients with SAHI than in healthy subjects, due to increased baseline activity of the mesolimbic dopamine system. 2…
ID
Source
Brief title
Condition
- Schizophrenia and other psychotic disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The decrease in [123I]IBZM-Binding Potential after amphetamine challenge.
Secondary outcome
The baseline [123I]IBZM binding potential ([123I]IBZM-BP)
Background summary
According to the social defeat hypothesis the long-term experience of social
exclusion or social defeat leads to enhanced baseline activity and/or
sensitization of the mesolimbic dopamine (DA) system and puts the individual at
increased risk for psychotic disorder and/or schizophrenia. This pilot study
tests the hypothesis by comparing DAergic function in two groups who are
expected to differ greatly: (1) young adults with a severe, acquired hearing
impairment (SAHI) who cannot participate in conversations and feel socially
excluded; (2) healthy peers.
Study objective
To test the following hypotheses:
1. The baseline [123I]IBZM binding potential ([123I]IBZM-BP) in the ventral
striatum is smaller in patients with SAHI than in healthy subjects, due to
increased baseline activity of the mesolimbic dopamine system.
2. The decrease in [123I]IBZM-BP after amphetamine challenge is significantly
greater in patients with SAHI than in healthy subjects.
3. There is a greater psychological/behavioural response to amphetamine
(happiness, restlessness, increased level of energy) in subjects with SAHI than
in healthy subjects.
Study design
Comparison of 15 subjects with Severe Acquired Hearing Impairment to 15 healthy
subjects.
Subjects will be examined using SPECT-imaging with the D2 tracer
[123I]iodobenzamide.
In one session, baseline D2 receptor binding and endogenous DA release after
stimulation with D-amphetamine sulphate (0.3 mg/kg iv) will be assessed
(bolus/constant infusion technique). Patients and healthy subjects will be
matched for age, sex and smoking status.
Study burden and risks
The study includes two visits: 1. Screening 2. Investigation.
During the investigation subjects will receive an intravenous infusion in each
arm and have to lie still in scanner, for 2 x 50 minutes.
The effective dose for the whole SPECT study is approximately 6.1 mSv, which is
within an acceptable range for healthy volunteers.
The major somatic side effects of amphetamine infusion are cardiovascular
(hypertension, palpitations, tachycardia, orthostatic hypotension).
The psychological/behavioral effects of amphetamine are increased level of
alertness, talkativeness, agitation, mood changes and anxiety. These effects
are transient and, at this dose, well tolerated.
Meibergdreef 9
1105 AZ Amsterdam
Nederland
Meibergdreef 9
1105 AZ Amsterdam
Nederland
Listed location countries
Age
Inclusion criteria
1. Patients: severe acquired hearing impairment, which impedes normal conversation and age 18-25 years.
2. Healthy subjects: age 18-25 years.
Exclusion criteria
Presence of psychotic disorder and use of illicit drugs
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
In other registers
| Register | ID |
|---|---|
| CCMO | NL24257.018.08 |
| OMON | NL-OMON23010 |