What is the mechanism of action for SSRIs?

The mechanism of action for selective serotonin reuptake inhibitors (SSRIs) primarily involves increasing serotonin levels in the brain. They achieve this by selectively blocking the reuptake of serotonin (5-HT) at the synaptic cleft, which means that serotonin remains available to bind to its receptors for a longer period of time. This enhanced availability of serotonin is believed to contribute to the alleviation of symptoms associated with depression and anxiety disorders, making SSRIs effective in improving mood and emotional state.

In contrast, the other options refer to mechanisms that do not accurately represent how SSRIs work. The inhibition of dopamine production and the stimulation of norepinephrine release relate to different classes of medications that target different neurotransmitter systems in the brain. Blocking neuronal calcium channels is a mechanism seen in other types of pharmacological agents, such as certain anticonvulsants or cardiovascular drugs, and is not relevant to the action of SSRIs.