The levels of the whole blood glial cell line-derived neurotrophic factor (GDNF) has been shown to be decreased in remitted patients with mood disorders[178] and one post-mortem study showed an increase in GDNF concentration in the PC of patients with depressive disorder[44], therefore suggesting its involvement in the pathophysiology of mood disorders and suicidality. The gene discussed is GDNF; the disease is depressive disorder.