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Dopamine D2 and D3 Receptor Occupancy and Clinical Response in Older Patients With Schizophrenia

NCT00825045 · Status: UNKNOWN · Phase: NA · Type: INTERVENTIONAL · Enrollment: 14

Last updated 2020-02-07

No results posted yet for this study

Summary

This study will provide information regarding dopamine D2/D3 occupancy related with clinical/adverse effects in older people with schizophrenia and schizoaffective disorder. The results of this study will also show an appropriate dose range in order to evade undesirable adverse effects while deriving therapeutic effects, which will directly serve to guide physicians in clinical practice. Furthermore, the findings of this study will elucidate mechanisms underlying older people's increased sensitivity to antipsychotic drugs. In addition, the contribution of D2 and D3 in mediating antipsychotic response will be contrasted, using 2 radiotracers, which has never been tested in an older population.

The hypotheses are as follows: First, clinical response (i.e., a ≥ 20% decrease in the Brief Psychiatric Rating Scale total score) will be achieved in older patients with occupancy that is lower than the threshold of 60% in historical young controls. Second, prolactin elevation and EPS will be detected in older patients with occupancies that are lower than the thresholds of 72 and 78% reported in historical young controls. Third, dopamine D2 receptor occupancy will be inversely correlated with subjective well-beings. Fourth, the binding potential and receptor occupancy will be at least 20% lower with \[11C\]-(+)-PHNO than with \[11C\]-raclopride in the caudate/putamen. Fifth, the binding of \[11C\]-(+)-PHNO in the globus pallidus will be higher than that of \[11C\]-raclopride.

Conditions

  • Schizophrenia
  • Schizoaffective Disorder
  • Schizophreniform Disorder

Interventions

DRUG

risperidone

Following the baseline clinical and cognitive assessments, risperidone will be initiated at 0.5-1.0 mg/day and subsequently increased by 0.25 - 1.0 mg on a weekly basis with the target of clinical stabilization (i.e. 20 or more % reduction in the total BPRS score) until a maximum dose of 4.0 mg/day is reached. To achieve this, a weekly assessment with BPRS will be performed. Physicians-of-record will be closely liaised with investigators. Dosage modification will be performed following this dosing schedule, however, this can be changed by treating physicians to meet clinical necessity. For example, in case psychotic symptoms are not controlled by this dosing schedule, facilitated dose increment will be allowed.

Sponsors & Collaborators

  • Centre for Addiction and Mental Health

    lead OTHER

Principal Investigators

  • Ariel Graff-Guerrero, MD, PhD · Centre for Addiction and Mental Health

Study Design

Allocation
NA
Purpose
TREATMENT
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
50 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2008-12-31
Primary Completion
2020-12-31
Completion
2020-12-31

Countries

  • Canada

Study Locations

More Related Trials

Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00825045 on ClinicalTrials.gov