The therapeutic action of monoamine oxidase inhibitors (MAOIs) blocks neurotransmitter reuptake, causing:

A) increased concentration of neurotransmitters in the synaptic gap.
B) decreased concentration of neurotransmitters in serum.
C) destruction of receptor sites.
D) limbic system stimulation.

If the reuptake of a substance is inhibited, then it accumulates in the synaptic gap and its concentration increases, permitting the ease of the transmission of impulses across the synaptic gap. Normal transmission of impulses across synaptic gaps is consistent with a normal rather than a depressed mood. The other options are not associated with blocking neurotransmitter reuptake.