Amisulpride, sold under the brand names Socian and Barhemsys, is a medication used in the treatment of schizophrenia, acute psychotic episodes, depression, and nausea and vomiting. It is specifically used at lower doses intravenously to prevent and treat postoperative nausea and vomiting, at low doses by mouth to treat depression, and at higher doses by mouth to treat psychosis.

It is usually classed with the atypical antipsychotics. Chemically it is a benzamide and like other benzamide antipsychotics, such as sulpiride, it is associated with a high risk of elevating blood levels of the lactation hormone, prolactin (thereby potentially causing the absence of the menstrual cycle, breast enlargement, even in males, breast milk secretion not related to breastfeeding, impaired fertility, impotence, breast pain, etc.), and a low risk, relative to the typical antipsychotics, of causing movement disorders.

Amisulpride is indicated for use in the United States in adults for the prevention of postoperative nausea and vomiting (PONV), either alone or in combination with an antiemetic of a different class; and to treat PONV in those who have received antiemetic prophylaxis with an agent of a different class or have not received prophylaxis.

Amisulpride is believed to work by blocking, or antagonizing, the dopamine D₂ receptor, reducing its signalling. The effectiveness of amisulpride in treating dysthymia and the negative symptoms of schizophrenia is believed to stem from its blockade of the presynaptic dopamine D₂ and D₃ autoreceptors. These presynaptic receptors regulate the release of dopamine into the synapse, so by blocking them amisulpride increases dopamine concentrations in the synapse. This increased dopamine concentration is theorized to act on dopamine D₁ receptors to relieve depressive symptoms (in dysthymia) and the negative symptoms of schizophrenia.

It was introduced by Sanofi-Aventis in the 1990s. Its patent expired by 2008, and generic formulations became available. It is marketed in all English-speaking countries except for Canada.

Although according to other studies it appears to have comparable efficacy to olanzapine in the treatment of schizophrenia, amisulpride augmentation, similarly to sulpiride augmentation, has been considered a viable treatment option (although this is based on low-quality evidence) in clozapine-resistant cases of schizophrenia. Another recent study concluded that amisulpride is an appropriate first-line treatment for the management of acute psychosis.

Amisulpride is approved and used at low doses in the treatment of dysthymia and major depressive disorder. Whereas typical doses used in schizophrenia block postsynaptic dopamine D₂-like receptors and reduce dopaminergic neurotransmission, low doses of amisulpride preferentially block presynaptic dopamine D₂ and D₃ autoreceptors and thereby disinhibit dopamine release and enhance dopaminergic neurotransmission. A 2010 Cochrane review found that low-dose amisulpride was effective in the treatment of dysthymia. Likewise, a 2024 literature review found that low-dose amisulpride was effective for dysthymia. The drug is approved for depression specifically in Italy, Greece, and certain other European countries.

Amisulpride is indicated for use in the United States in adults for the prevention of postoperative nausea and vomiting (PONV), either alone or in combination with an antiemetic of a different class; and to treat PONV in those who have received antiemetic prophylaxis with an agent of a different class or have not received prophylaxis.