Roxindole (developmental code name EMD-49980) is a dopaminergic and serotonergic drug which was originally developed by Merck KGaA for the treatment of schizophrenia. In clinical trials its antipsychotic efficacy was only modest but it was unexpectedly found to produce potent and rapid antidepressant and anxiolytic effects. As a result, roxindole was further researched for the treatment of depression instead. It has also been investigated as a therapy for Parkinson's disease and prolactinoma. However, it has never been marketed.

Roxindole acts as an agonist at the following receptors:

At D₂ and possibly D₃ receptors roxindole is a partial agonist with preferential actions at autoreceptors and has been touted as a 'selective' autoreceptor agonist, hence the justification of its application as an antipsychotic. Weaker activity at the serotonin 1_B and 1_D receptors has been seen. It is also a serotonin reuptake inhibitor (IC₅₀ = 1.4 nM) and has been reported to act as a 5-HT_2A receptor antagonist as well.