Final answer:
Venlafaxine (Effexor) is classified as an SNRI, which inhibits the reuptake of both serotonin and norepinephrine in the brain to help treat depression with modestly increased efficiency and milder side effects compared to SSRIs.
Step-by-step explanation:
Venlafaxine, marketed as Effexor, is classified as an SNRI, which stands for Serotonin-Norepinephrine Reuptake Inhibitor. Unlike SSRIs, which selectively block the reuptake of serotonin, SNRIs inhibit the reuptake of both serotonin and norepinephrine. This results in increased levels of these neurotransmitters in the central nervous system, potentially leading to improved mood and reduced depression symptoms. It's important to note that SNRIs may have a modest increase in efficiency compared to SSRIs and generally have slightly milder side effects. Venlafaxine does not fall into the categories of MAOI, TCA, SSRI, or psychomotor stimulant.