Also see this explanation of the chemical basis is schizophrenia for context
The types of antipsychotics are as follows:
- Typical antipsychotics (dopamine antagonists)
- Atypical antipsychotics (5-HT2A Antagonist)
- Muscinaric agonists
In short, haloperidol, clozapine, and xanomeline reduce positive symptoms of schizophrenia and clozapine and xanomeline reduce the negative effects of schizophrenia
Typical anti-psychotics
These antagonise the inhibitory D2 receptor family, and increases the effect of dopamine.
The D1 receptor family is composed of the D1 and D5 receptors and is excitatory. The D2 receptor family is composed of the D2 through to D4 receptors and is inhibitory. G Proteins coupled to the D2 receptors family leads to decrease in cAMP and overall inhibition. The D1 receptor does the opposite.
Our main drug mentioned for this class is: Haloperidol
Atypical Antipsychotics
These are second generation antipsychotics, which are antagonists at some or all of the dopamine 2 family receptors and or 5-HT2A receptors.
Our main drug mentioned for this class is: Clozapine
Muscarinic agonists
If a mAChR antagonist like hyoscine can cause psychotic like effects, it is theorised that a mAChR agonist, like Xanomeline, could work.