(a, e) Control subject without psychopathology or treatment (control); (b, f) untreated subject with mood disorder (MD); (c, g) subject with mood disorder treated with antidepressants only (MD*ADT); and (d, h) subject with mood disorder treated with antidepressants and benzodiazepines (MD*ADT*BZD), average age is 48 years, two males and two females. The subgranular zone (SGZ) and granule cell layer (GCL) are indicated. (a–d) Nestin-immunoreactive (IR) cells and capillaries appear in brown (diaminobenzidine). Cells are stained for Nissl using Cresyl Violet. (e–h) Ki-67-IR cells appear in black (nickel-diaminobenzidine). Cell cytoplasm is stained with eosin. The control (a, e) and MD*ADT (c, g) show more nestin-IR and cells (arrows) and capillaries (in brown) and more Ki-67-IR cells (arrows) compared with the untreated MD (b, f). The MD*ADT*BZD (d, h) shows as few nestin-IR and cells (arrows) and capillaries (in brown) as the control (b, f) but more Ki-67-IR cells (arrows) compared with the untreated MD (b, f). In the untreated MD (f), Ki-67-IR cells do not show the classical SGZ localization, thus most probably they are not replicating NPCs.