Summary of Neurochemical Findings in Schizophrenia
Neurotransmitter | Strength of evidence |
---|---|
+/− = weak; + = moderate; ++ = good; +++ = strong; ++++ = very strong shown by meta-analysis. ↑ = increase; ↓ = decrease. α Though much of the increase is due to antipsychotic medication. | |
Dopamine | |
Striatal D2 receptors ↑ | ++++α |
Dopamine content or metabolism ↑ | +++α |
Amphetamine-stimulated dopamine transmission ↑ | +++ |
Cortical D1 receptors ↓ | + |
Cortical D3 receptors ↑ | + |
D4 receptors ↑ | +/− |
Abnormal configuration of D2 receptors | +/− |
Altered dopamine receptor–G protein coupling | +/− |
Serotonin | |
Cortical 5-HT2A receptors ↓ | +++ |
Cortical 5-HT1A receptors ↑ | ++ |
CSF 5-HIAA concentrations related to negative symptoms | + |
Glutamate | |
Expression of non-NMDA receptors in the temporal cortex and hippocampus ↓ | ++ |
Cortical expression of some NMDA receptor subunits ↑ | ++ |
Glutamate reuptake in frontal cortex ↑ | + |
Cortical glutamate release ↓ | + |
Altered concentrations of glutamate and metabolites | +/− |