Accumulating research supports the use of the Wistar-Kyoto (WKY) rat as a valid model of endogenous stress susceptibility and depression that exhibits various depressive-like phenotypes (e.g. behavioural inhibition, psychomotor slowing, anhedonia, social withdrawal, anxiety, cognitive deficits), as well as key neurochemical and endocrine parallels to MDD (e.g. deficient monoamine and neurotrophin signaling, aberrant glutamatergic function, hippocampal and cortical volume loss, and hyperactive hypothalamic-pituitary-adrenal (HPA) axis) (for review, [7]). The gene discussed is BDNF; the disease is major depressive disorder.