Answered by Bernhard Baune
The pharmacological difference between monomodal and multimodal drug action is based on the number of different modes of action involved. For example, when a drug acts as a reuptake inhibitor only (regardless of the monoamine blocked) then this is a single mode of action and defined as a monomodal drug. In contrast, when more than one mode of action is involved (e.g. reuptake inhibition and receptor activity as pharmacological targets) then this is defined as multimodal drug action (see Figure 1). It appears that combining multiple modes of monoaminergic action may enhance the efficacy of antidepressant treatment for some patients.