The role of the PACAP signaling system in depression.

Major Depressive Disorder (MDD) is a psychiatric condition that represents an important public health concern in modern society. Current pharmacological antidepressant treatments improve depressive symptoms through complex mechanisms that are incompletely understood. There is a consensus that in the clinic they act through the modulation of monoaminergic neurotransmission, primarily involving the serotonin and norepinephrine systems.