Amisulpride, a benzamide derivative, shows a unique therapeutic profile being atypical antipsychotic. At low doses, it enhances dopaminergic neurotransmission by preferentially blocking presynaptic dopamine D2/D3 autoreceptors. At higher doses, amisupride antagonises postsynaptic dopamine D2 and D3 receptors, preferentially in the limbic system rather than the striatum, thereby reducing dopaminergic transmission. In addition its antagonism at serotonin 5-HT7 receptors likely underlies the antidepressant actions. Amisulpride is approved for clinical use in treating schizophrenia in a number of European countries and also for treating dysthymia, a mild form of depression, in Italy.

Pimavanserin, marketed under the trade name Nuplazid, a non-dopaminergic atypical antipsychotic developed by Acadia Pharmaceuticals is the first and only medication approved by the U.S. Food and Drug Administration (FDA) for the treatment of hallucinations and delusions associated with Parkinson’s disease psychosis. The mechanism of action of pimavanserin in the treatment of hallucinations and delusions associated with Parkinson’s disease psychosis is unknown. However, the effect of pimavanserin could be mediated through a combination of inverse agonist and antagonist activity at serotonin 5-HT2A receptors and to a lesser extent at serotonin 5-HT2C receptors. In vitro, pimavanserin acts as an inverse agonist and antagonist at serotonin 5-HT2A receptors with high binding affinity (Ki value 0.087 nM) and at serotonin 5-HT2C receptors with lower binding affinity (Ki value 0.44 nM). Pimavanserin shows low binding to sigma 1 receptors (Ki value 120 nM) and has no appreciable affinity (Ki value >300 nM), to serotonin 5-HT2B, dopaminergic (including D2), muscarinic, histaminergic, or adrenergic receptors, or to calcium channels. Pimavanserin was approved by the FDA to treat hallucinations and delusions associated with psychosis experienced by some people with Parkinson's disease on April 29, 2016.

Brexpiprazole is a novel D2 dopamine and serotonin 1A partial agonist, called serotonin-dopamine activity modulator (SDAM), and a potent antagonist of serotonin 2A receptors, noradrenergic alpha 1B and 2C receptors. Brexpiprazole is approved for the treatment of schizophrenia, and as an adjunctive treatment for major depressive disorder (MDD). Although it failed Phase II clinical trials for ADHD, it has been designed to provide improved efficacy and tolerability (e.g., less akathisia, restlessness and/or insomnia) over established adjunctive treatments for major depressive disorder (MDD).Brexpiprazole is sold under the brand name Rexulti. Although the mechanism of action of brexpiprazole in the treatment of MDD and schizophrenia is unclear, the efficacy of brexpiprazole may be attributed to partial agonist activity at serotonin 1A and dopamine D2 receptors, and antagonist activity at serotonin 2A receptors.

Cariprazine is an antipsychotic approved by FDA for the treatment of schizophrenia and bipolar I disorder. The drug has a unique clinical action which is explained by its ability to act on dopamine D3 receptors. Pharmacology studies revealed that cariprazine is a dual partial agonist of dopamine D2 and D3 receptors as well as serotonin 5HT1a, 2a and 2b receptors.

Lurasidone is a novel antipsychotic agent approved for the treatment of schizophrenia in a number of countries including the UK and is also approved in the USA and Canada for the treatment of bipolar depression as either a monotherapy or adjunctive therapy with lithium or valproate. In addition, lurasidone is in phase III of a clinical trial for the treatment patient with major depressive disorder and for the treatment of irritability associated with autistic disorder. The mechanism of action of lurasidone, as with other drugs having efficacy in schizophrenia, is unknown but is known, that lurasidone has a high affinity for dopamine D2, serotonin 5-HT2A and serotonin 5-HT7 receptors where it has antagonist effects. In addition, lurasidone is a partial agonist at the serotonin 5-HT1A receptor and has no appreciable affinity for histamine or muscarinic receptors.

Iloperidone, also known as Fanapt, Fanapta, and previously known as Zomaril, is an atypical antipsychotic for the treatment of schizophrenia. Iloperidone shows high affinity and maximal receptor occupancy for dopamine D2 receptors in the caudate nucleus and putamen of the brains of schizophrenic patients. The improvement in cognition is attributed to iloperidone's high affinity for α adrenergic receptors. Iloperidone also binds with high affinity to serotonin 5-HT2a and dopamine 3 receptors. Iloperidone binds with moderate affinity to dopamine D4, serotonin 5-HT6 and 5-HT7, and norepinephrine NEα1 receptors. Furthermore, iloperidone binds with weak affinity to serotonin 5-HT1A, dopamine D1, and histamine H1 receptors. Iloperidone is indicated for the treatment of acute schizophrenia.

Asenapine is an antipsychotic drug. The mechanism of action of asenapine, as with other drugs having efficacy in schizophrenia and bipolar disorder, is unknown. Asenapine exhibits high affinity for serotonin 5-HT1A, 5-HT1B, 5-HT2A, 5-HT2B, 5-HT2C, 5-HT5, 5-HT6, and 5-HT7 receptors, dopamine D2, D3, D4, and D1 receptors, α1 and α2-adrenergic receptors, and histamine H1 receptors, and moderate affinity for H2 receptors. In in vitro assays asenapine acts as an antagonist at these receptors. It has been suggested that the efficacy of asenapine in schizophrenia is mediated through a combination of antagonist activity at D2 and 5-HT2A receptors. Asenapine is approved by the FDA for the acute treatment of schizophrenia in adults and for the acute treatment of manic or mixed episodes associated with bipolar I disorder, with or without psychotic features, in adults.

Paliperidone (9-OH-risperidone) is the primary active metabolite of the older antipsychotic risperidone. While its specific mechanism of action is unknown, it is believed that paliperidone and risperidone act via similar if not the same pathways. It has been proposed that the drug's therapeutic activity in schizophrenia is mediated through a combination of central dopamine Type 2 (D2) and serotonin Type 2 (5HT2A) receptor antagonism. Paliperidone is also active as an antagonist at alpha 1 and alpha 2 adrenergic receptors and H1 histaminergic receptors, which may explain some of the other effects of the drug. Paliperidone was approved by the FDA for treatment of schizophrenia on December 20, 2006. Very common adverse effects are: headache, tachycardia, somnolence and insomnia.

Aripiprazole is the first next-generation atypical antipsychotic. The unique actions of aripiprazole in humans are likely a combination of "functionally selective" activation of D(2) (and possibly D(3))-dopamine receptors and serotonin 5-HT(1A) receptors, coupled with inhibition of 5-HT(2A) receptors. Aripiprazole was approved by FDA (Abilify trade name) for the treatment of schizophrenia; manic and mixed episodes associated with bipolar I disorder; major depressive disorder; irritability associated with autistic disorder; Tourette’s disorder and agitation associated with schizophrenia or bipolar mania.

Ziprasidone is atypical antipsychotic, approved by the U.S. Food and Drug Administration for the treatment of schizophrenia, and acute mania and mixed states associated with bipolar disorder. Intramuscilar injections of Ziprasidone are indicated for rapid control of the agitation in schizophrenic patients. Ziprasidone is used off-label for treatment of major depressive disorder, anxiety, obsessive compulsive disorder, borderline personality disorder. Ziprasidone functions as an antagonist at the D2, 5HT2A, and 5HT1D receptors, and as an agonist at the 5HT1A receptor.