About Anti-Anxiety Drugs
There are several different classes of anti-anxiety drugs, each of which has its own mechanism of action.
Benzodiazapenes such as Klonopin, Xanax and Ativan have sedative and anticonvulsant properties. They depress the central nervous system by acting on the receptors of the neurotransmitter GABA. The benzodiazapene binds to the receptor, causing it to have a higher affinity for GABA, which acts as an inhibitory neurotransmitter. This causes depression of the central nervous system, which is often overactive in those with anxiety disorders. Benzodiazapenes have the potential for addiction and are sometimes used as recreational drugs.
Other anti-anxiety drugs work on the neurotransmitter serotonin. Serotonin plays a role in multiple physiological processes and has effects on sleep, appetite, mood, metabolism and body temperature. The drug BuSpar is thought to work on a specific serotonin receptor, 5-HT1A, and potentiates serotonin's inhibitory central nervous system effects, decreasing anxiety and promoting normal sleeping and eating patterns. Selective serotonin reuptake inhibitors (SSRIs), some of which are indicated for anxiety, increase the levels of serotonin in the brain instead of working on the receptors.
Barbituates are strong central nervous system depressants. Like benzodiazapenes, they increase the inhibitory effects of GABA, but they also block the receptors for glutamate, which is an excitatory neurotransmitter. This makes barbituates extremely potent sedatives, and they can be highly addictive. Barbituates are usually only prescribed for very short periods of time, and only if other drugs have failed.