Molecular imaging of schizophrenia: neurochemical findings in a heterogeneous and evolving disorder.

Molecular imaging of schizophrenia: neurochemical findings in a heterogeneous and evolving disorder. Behav Brain Res. 2020 Nov 13;:113004 Authors: Cumming P, Abi-Dargham A, Gründer G Abstract The past four decades have seen enormous efforts placed on a search for molecular markers of schizophrenia using positron emission tomography (PET) and single photon emission computed tomography (SPECT). In this narrative review, we cast a broad net to define and summarize what we have learned about schizophrenia from molecular imaging studies. PET studies of brain energy metabolism with the glucose analogue FDG have generally failed to show a defect in patients with schizophrenia, but tend to indicate a loss of metabolic coherence between different brain regions. An early finding of significantly increased striatal trapping of the dopamine synthesis tracer FDOPA has survived a meta-analysis of many replications, but the increase is not pathognomonic of the disorder, since one half of patients have entirely normal dopamine synthesis capacity. Similarly, competition SPECT studies show greater basal and amphetamine-evoked dopamine occupancy at post-synaptic dopamine D2/3 receptors in patients with schizophrenia, but the difference is likewise not pathognomonic. We propose that molecular imaging studies of brain dopamine indicate neurochemical heterogeneity within the diagnostic entity of schizophrenia. Occupancy studies have established the relev...
Source: Behavioural Brain Research - Category: Neurology Authors: Tags: Behav Brain Res Source Type: research