are neurotransmitters which have the ability to affect the levels of more than one neurotransmitter which implies that the drugs can bind to more than one receptor for various neurotransmitters in the body at the synapses.

MIXED-FUNCTION ANTIDEPRESSANTS: "Mixed-function antidepressants are typically used for their multi-dimensional approach to the nervous system usually having an effect on more than one neurotransmitter."