Buspar is a 1A serotonin partial agonist. (The “5-HT1A” receptor is a subtype of serotonin receptor in the brain.) A partial agonist partially binds to and activates a specific receptor (the part of the brain in which a neurochemical binds with after it’s released to stimulate an action) to create the same or similar response in the body that the neurotransmitter (here, serotonin) would. Studies have shown that patients with panic disorder and anxiety have impaired 5-HT1A receptor function. Buspar is supposed to correct this. Presynaptically (meaning, on the firing end) this agonist works to enhance serotonergic activities, and postsynaptically (the receiving end) it diminishes serotonergic activity.
Serotonin’s function in the brain is to regulate signal intensity. Therefore, an imbalance of serotonin can cause anxiety and mood disorders. There are theories that suggest that people with anxiety disorders produce less dopamine and serotonin, and therefore the brain undergoes a chemical change and has less serotonin receptors to receive them (as the body needs more receptors to receive the excess anxiety/fear neurochemicals like adrenaline). You then become more prone to feeling anxious all the time. Environmental stressors can also affect serotonin levels causing you to feel more anxious. It takes anywhere from 2-6 weeks for Buspar to make any changes in your brain and for you to feel the effect. Its effects have been proclaimed to be mild.
Because anxiety is linked to both GABA and serotonin, medications that affect these neurotransmitters can help manage anxiety. Some examples include benzodiazepines like Xanax, Klonopin, Valium, Ativan, Serax, Librium (these enhance GABA); beta blockers, like Inderal, for social anxiety (blocks epinephrine); tricyclic antidepressants, like Tofranil, (increases the levels of norepinephrine and serotonin, decreases acetylcholine); MAOIs, like Nardil, (changes levels of norepinephrine, serotonin, and dopamine); SSRIs like Zoloft, Paxil, Prozac, Lexapro, Celexa (blocks the reuptake of serotonin, creating more serotonin in the brian); SNRIs like Effexor, Cymbalta (blocks the reuptake of serotonin and norepinephrine in the brain); Buspar (mild tranquilizer and 1A serotonin partial agonist); and anticonvulsants like Depakote, Lyrica, Gabapentin (may enhance GABA function).
The most common drugs prescribed for panic are SSRIs or SNRIs in combination with benzos. The most common drugs prescribed for generalized anxiety are SSRIs, SNRIs, Buspar, and tricyclic antidepressants, in combination with benzos.