Final answer:
Fluoxetine is an antidepressant that increases serotonin levels in the brain by inhibiting its reuptake, and is categorized as an SSRI.
Step-by-step explanation:
Fluoxetine, a major drug for treating depression, effectively increases the neurotransmitter serotonin in the cortex. This medication is classified as a Selective Serotonin Reuptake Inhibitor (SSRI), which works by blocking the reuptake of serotonin into the presynaptic neuron, leading to an increased concentration of serotonin in the synaptic cleft and hence enhancing mood. Prozac, a well-known brand name for fluoxetine, has been found to modulate these effects and is often prescribed to treat depressive disorders.