Antidepressant effects are arising mainly from the interaction of serotonergic, noradrenergic, dopaminergic and glutamatergic neurotransmitter systems. Multimodal antidepressants exert, due to various affinities to different receptor subtypes, various pharmacodynamic effects depending on the dose.
Also, on the receptor and molecular level, a common denominator of action of some antidepressants and antipsychotics can be found, so that these medicaments can mutually potentiate in their antidepressant effect.