MedicalResearch: What is the background for this study?
Dr. Slifstein: There has been considerable basic and clinical neuroscience research showing that the neurotransmitter dopamine plays a role in tuning cognitive processes taking place in the cortex. It has long been thought that dopamine is involved in the cognitive difficulties experienced by patients with schizophrenia, but it has been challenging to study dopamine in the cortex and other parts of the brain except in a deep structure rich in this neurotransmitter and its receptors, the striatum. In our study, we used an experimental design with Positron Emission Tomography (PET) imaging that allowed us to infer the amount of dopamine in the cortex.
MedicalResearch: What are the main findings?
Dr. Slifstein: The main findings are that patients with schizophrenia do not have enough dopamine in the cortex, which may cause the cortex to function suboptimally. Because dopamine fine tunes the signal to noise ratio and affects the manner in which the cortex processes information, deficits are likely to lead to difficulties in this function.
MedicalResearch: What should clinicians and patients take away from your report?
Dr. Slifstein: A predominant feature in the brains of patients with schizophrenia is a widespread lack of dopamine, affecting most of the brain other than the striatum. We need to treat this deficit to improve cognitive deficits.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr. Slifstein: We need to replicate this finding, as this is only a first report. We need to understand how this deficit emerges, and how to treat it without worsening the conditions in the other parts of the brain, especially the striatum, in which patients with schizophrenia have excess dopamine.
Slifstein M, van de Giessen E, Van Snellenberg J, et al. Deficits in Prefrontal Cortical and Extrastriatal Dopamine Release in Schizophrenia: A Positron Emission Tomographic Functional Magnetic Resonance Imaging Study. JAMA Psychiatry. Published online February 04, 2015. doi:10.1001/jamapsychiatry.2014.2414.
MedicalResearch.com Interview with:, & Mark Slifstein, PhD (2015). Patients With Schizophrenia Lack Sufficient Dopamine in Brain MedicalResearch.com