Roxindole (developmental code name EMD-49980) is a dopaminergic and serotonergic drug which was originally developed by Merck KGaA for the treatment of schizophrenia.

[1][2][3] In clinical trials its antipsychotic efficacy was only modest but it was unexpectedly found to produce potent and rapid antidepressant and anxiolytic effects.

[2][3] As a result, roxindole was further researched for the treatment of depression instead.

[1][4] It has also been investigated as a therapy for Parkinson's disease and prolactinoma.

[12] It is also a serotonin reuptake inhibitor (IC50 = 1.4 nM) and has been reported to act as a 5-HT2A receptor antagonist as well.