Benzodiazepine agonists are GABA. This is an inhibitory neurotransmitter, and is targeted during the treatment of anxiety. Benzodiazepine class drugs are positive allosteric modulators (PAM) at the orthosteric site of the GABA_A receptor. This allows it to increase the excitability of the neuron, leading to increased transmission.
Although benzodiazepines are typically used as anxiolytic drugs, they can also be used as sedatives. Although the benzodiazepines used for treating anxiety typically have a long half-life (~40 hours), there are others with shorter half-lives (2-4 hours) that are more useful for the treatment of insomnia. It is not desirable to an a sedative with long half-lives, due to the disruption they cause to a patient’s life. For example, a long half-life of a sedative would prevent driving due to the risk of them falling asleep while driving. Therefore, there are a range of drugs within the benzodiazepine class with varying half-lives.