Dopamine, a chemical in the brain, has been linked to schizophrenia for a number of years.
More recently, there is evidence that certain areas affected in schizophrenia (e.g.
motivation, cognition) may reflect too little dopamine, whereas symptoms like hallucinations
and delusions have been linked to too much dopamine.
This study is designed to evaluate the safety, tolerability, and efficacy of giving L-dopa
(Sinemet) to see if it will improve those symptoms related to too little dopamine. L-dopa has
been approved for other medical conditions (e.g. Parkinson's disease) and works to increase
levels of dopamine.
The investigators are linking this study with neuroimaging (fMRI) which will allows us to
link any changes the investigators might find in clinical symptoms with changes in the brain.
This information can prove useful in better understanding the mechanisms that account for
these symptoms, as well as possible new treatments.
At present , treatments for these other symptoms that seem important in functional measures
of outcome (i.e. deficit symptoms, including amotivation; cognitive symptoms) in
schizophrenia have not proven particularly effective. It is hoped that L-dopa may provide a
treatment that is more effective; going forward, this information would also be useful in
drug development and future lines of investigation.
1. L-dopa will prove effective in improving deficit (also called 'primary negative' e.g.
amotivation) and cognitive symptoms in schizophrenia.
2. It will be well tolerated and not increase risk of psychotic symptoms when administered
in conjunction with their regular antipsychotic medications.
Phase:
Phase 2
Details
Lead Sponsor:
Centre for Addiction and Mental Health
Treatments:
Antipsychotic Agents Carbidopa Carbidopa, levodopa drug combination Levodopa