1. To examine whether there is an increase in (nigro)striatal dopaminergic functioning in individuals of West-African descent relative to those of Dutch descent (assessed in older participants with DAT SPECT and with NM-MRI in the entire sample). (…
ID
Source
Brief title
Condition
- Neurological disorders NEC
- Schizophrenia and other psychotic disorders
- Economic and housing issues
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
(1) In older participants (>=50 years old) only: Striatal dopamine transporter
(DAT) availability, as assessed through [123I]-FP-CIT SPECT by examining the
specific striatal [123I]-FP-CIT binding.
(2) In all participants: Nigrostriatal dopaminergic functioning, as assessed
with the neuromelanin-sensitive MRI (NM-MRI) contrast-to-noise ratio (CNR) in
the substantia nigra.
These outcomes will be compared between participants of West-African and Dutch
descent.
Secondary outcome
1. Subjective social status, i.e. the participant*s perceived standing (1)
within Dutch society and (2) their community. This will be measured with the
MacArthur Subjective Social Status Scale (MSSSS).
2. Scores on the Barratt Simplified Measure of Social Status (BSMSS), which
reflects socioeconomic status (SES), i.e. the participant*s objective
socioeconomic position in society, based on educational level and occupational
status. Personal and household income will also be quantified.
These outcomes will be correlated with striatal dopaminergic functioning and
compared between West-African and Dutch participants.
Background summary
Compared to individuals of European descent, those of African descent show a
greater risk of developing schizophrenia, but a lower risk of developing
Parkinson's disease (PD). Schizophrenia is characterized by increased striatal
dopaminergic functioning, whereas PD is the result of nigrostriatal dopamine
degeneration. Investigating the neurobiological mechanisms underlying
schizophrenia and PD can help explain racial disparities in disease risks.
Specifically, we hypothesize that an upregulation in striatal dopaminergic
functioning in African individuals relative to European individuals increases
the risk of schizophrenia, but protects against PD. These striatal dopaminergic
alterations might arise from genetic differences, but might also be linked to
variations in social stress exposure (e.g., stress resulting from low status).
Study objective
1. To examine whether there is an increase in (nigro)striatal dopaminergic
functioning in individuals of West-African descent relative to those of Dutch
descent (assessed in older participants with DAT SPECT and with NM-MRI in the
entire sample). (Primary objective)
2. To examine whether (nigro)striatal dopaminergic functioning is in both
racial groups negatively associated with measures of social status. (Secondary
objective)
Study design
Cross-sectional.
Study burden and risks
Burden and risks:
The burden associated with this study is moderate, the risk is minimal.
Subjects visit the Amsterdam UMC two or three times: for psychological
assessments, an MRI-scan, and (older participants only) a SPECT scan (depending
on the availability of the participant and the scanners, the MRI- and SPECT
scans can sometimes be planned on the same day for older participants, in which
case they will only have to visit two times). For the SPECT scan, participants
will receive a dose of approximately 111 MBq [123I]-FP-CIT, which induces a
radiation burden of approximately 2.7 mSv. In the Netherlands, the natural
background activity per year is approximately 2.9 mSv, so the additional
radiation induced by participation in this study is similar to the amount of
natural background activity detected in one year. A small amount of blood will
also be taken from each participant. The methods applied in this study are part
of routine clinical care and have been widely used in scientific studies
worldwide and at the Amsterdam UMC.
Benefits:
There are no direct benefits to the participants. However, the study will
contribute to our understanding of the aetiology of schizophrenia and PD. The
first step towards prevention is understanding the biological mechanisms. Thus
far, individuals of African descent have been largely excluded from
neuroimaging studies, which has resulted in a knowledge gap about their
neurobiology and health. For the prevention of schizophrenia among people of
African descent it is important to know whether there is an increase in
nigrostriatal dopaminergic functioning. If so, it is vital to know whether the
increase is due to genetic factors or low status. The findings on Africans may
provide clues for prevention of PD, and directly inform clinical practice
(e.g., by contributing to the calibration of DAT SPECT standards/reference data
in different racial groups).
Meibergdreef 9
Amsterdam 1105AZ
NL
Meibergdreef 9
Amsterdam 1105AZ
NL
Listed location countries
Age
Inclusion criteria
1. Age 18-70 years old.
2. West-African or Dutch descent, as determined through self-report (parents
and grandparents should be born in the corresponding region). After the study
has been conducted, ancestry will be confirmed with genetic analysis.
3. Speaks Dutch or English.
Exclusion criteria
1. Present or past (suspected) presence of severe psychiatric illness, such as
schizophrenia or other psychotic disorder, bipolar disorder, depressive
disorder with psychotic features.
2. Present or past (suspected) presence of neurological disorder (e.g.,
Parkinson*s disease, epilepsy), evidence of brain damage, and/or other medical
illness (e.g., diabetes mellitus) that may affect brain function.
3. Current or recent (past three months) use of illicit drugs, as determined by
self-report and with a urinary drug test on the day of neuroimaging (the
results of this drug test will be checked after the participant has completed
the study). Participants will be tested on use of cannabis, amphetamines, XTC,
cocaine and opiates.
4. Lifetime use of illicit drugs (in particular opiates, amphetamines, XTC, and
cocaine; exclusion for other illicit drug use will be decided on a case-by-case
basis), if frequently taken (>10x lifetime use of drugs).
5. Lifetime cannabis use, if frequently taken (weekly use for at least a year).
6. Current or recent (past three months) use of dopamine-altering
medications/drugs that might influence neuroimaging of DAT availability,
namely: amphetamines, cannabis, cocaine, CNS stimulants phentermine or
ephedrines, modafinil, certain antidepressants (mazindol, bupropion,
radafaxine), adrenergic agonists, anticholinergic drugs, opioids, anesthetics
ketamine, PCP, or isoflurane.
7. Smoking or consuming caffeinated drinks during the period of six hours prior
to the DAT SPECT scan.
8. Participation in a scientific examination that used radiation, in the last
year.
9. (Non-removable) metal objects in or around the body.
10. In women: pregnancy (self-report or positive pregnancy test) and/or
lactation.
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| Other | https://osf.io/697s2 |
| CCMO | NL83230.018.22 |