Muscarinic M1 and M4 receptor agonists for schizophrenia: promising candidates for the therapeutic arsenal.

Schizophrenia is a syndrome which means drugs that activate muscarinic M1 and M4 receptors, as was the case for antipsychotic drugs acting on the dopamine D2 receptor, will not give optimal outcomes in everyone within the syndrome. Thus, it would be idle to identify people who are responsive to drugs activating the CHRM1 and 4. Given knowledge of actions of these receptors, it is possible treatment non-response could be restricted to sub-groups within the syndrome who have deficits in cortical CHRM1 or those with one of the cognitive endophenotypes that may be identifiable by changes in the blood transcriptome.