Figure 13. Schematic representation of the central neurocircuitry and its altered activity implicated in acute stress and melancholic depression (chronic stress system hyperactivation). Hyperfunctioning amygdala, hypofunctioning hippocampus and/or hypofunctioning mesocorticolimbic system (MCLS) could be associated with chronic hyperactivation of the PVN CRH-AVP system and predispose to melancholic depression. PVN: paraventricular nucleus; CRH: corticotropin-releasing hormone; AVP: arginine vasopressin. Activation is represented by solid green lines and inhibition by dashed red lines.