What is the primary mechanism of action for selective serotonin reuptake inhibitors (SSRIs) in treating premenstrual dysphoric disorder?

• A. Inhibition of serotonin reuptake
• B. Increase in dopamine levels
• C. Reduction of norepinephrine
• D. Blocking of estrogen receptors

Answer: (A)

The primary mechanism of action for selective serotonin reuptake inhibitors (SSRIs) in treating premenstrual dysphoric disorder (PMDD) is the inhibition of serotonin reuptake. SSRIs work by preventing the reabsorption of serotonin in the brain, which increases the availability of this neurotransmitter in the synaptic space. This enhancement of serotonergic neurotransmission is particularly beneficial in regulating mood and emotional stability, which are often disrupted in conditions like PMDD.

By increasing serotonin levels, SSRIs can alleviate the emotional and psychological symptoms associated with PMDD, such as irritability, mood swings, and depression. This is significant because serotonin plays a crucial role in mood regulation, and imbalances in serotonin levels are linked to many mood disorders.

The other options, while related to psychiatric or hormonal mechanisms, do not accurately describe the primary action of SSRIs. Dopamine levels are not directly increased by SSRIs; rather, the drugs primarily focus on serotonin pathways. Similarly, while norepinephrine is another neurotransmitter involved in mood regulation, SSRIs do not directly interact with norepinephrine levels in the same way that other classes of antidepressants, like norepinephrine reuptake inhibitors, might. Blocking estrogen receptors does not align with the