Editing Psychopharmacology (section)

===Antipsychotics===
All proven antipsychotics are postsynaptic dopamine receptor blockers (dopamine [[Receptor antagonist|antagonist]]s). For an antipsychotic to be effective, it generally requires a dopamine antagonism of 60%–80% of dopamine D<sub>2</sub> receptors.<ref name=Clinical />

[[Typical antipsychotic|First generation (typical) antipsychotics]]: Traditional [[neuroleptics]] modify several neurotransmitter systems, but their clinical effectiveness is most likely due to their ability to antagonize dopamine transmission by competitively blocking the receptors or by inhibiting dopamine release. The most serious and troublesome side effects of these classical antipsychotics are movement disorders that resemble the symptoms of [[Parkinson's disease]], because the neuroleptics antagonize dopamine receptors broadly, also reducing the normal dopamine-mediated inhibition of [[cholinergic]] cells in the [[striatum]].<ref name=Psychopharm />

[[Atypical antipsychotic|Second-generation (atypical) antipsychotics]]: The concept of "atypicality" is from the finding that second generation antipsychotics (SGAs) have a greater serotonin/dopamine ratio than earlier drugs, and might be associated with improved efficacy (particularly for the [[negative symptoms]] of psychosis) and reduced [[extrapyramidal symptoms|extrapyramidal side effects]]. Some of the efficacy of atypical antipsychotics may be due to 5-HT<sub>2</sub> antagonism or the blockade of other dopamine receptors. Agents that purely block 5-HT<sub>2</sub> or dopamine receptors other than D<sub>2</sub> have often failed as effective antipsychotics.<ref name=Clinical />