The nerves in your central nervous system (brain and spinal cord) are individual cells not directly connected to each other. Chemicals called neurotransmitters bridge the gap or synapse between each nerve, generated by one nerve and causing the receiving nerve to respond. Neurotransmitters such as noradrenalin and serotonin cause the nerve to fire, so they are called excitatory transmitters. On the other hand, the neurotransmitter gamma-aminobutyric acid (GABA for short) calms it down and can stop it firing altogether, so neutralising the excitatory effect. Each nerve has receptors into which the neurotransmitters bind. The GABA binds into its own receptor, thus exercising the sedating effect. The benzodiazepine also binds into the same receptor, and augments the calming effect.
The GABA receptor eventually adjusts to the presence of the benzodiazepine, and the combination is essential to the proper operation of the nerve cell. The concentration of GABA is not affected by benzodiazepines; they alter the affinity of the GABA for the receptor.
At this point the GABA receptor is said to be down-regulated. Withdrawing the drug leaves the receptor down-regulated, and the whole process of withdrawing and recovering from the drug is essentially one of restoring the GABA receptor’s proper functions so that it becomes up-regulated again. This takes time.
Fortunately there is little evidence that the drug causes permanent damage, so people can reasonably expect to recover their normal faculties.
