Benzodiazepine Addiction Study
Benzodiazepines are a class of drug compounds used to treat anxiety, as sleep aids and to calm patients for surgical procedures. They include Valium, Xanax and Ativan. And all are habit forming. An interesting bit of research now shows they cause addiction through the same mechanisms as opiate drugs like heroin or oxycodone.
The National Institute on Drug Abuse funded research (press release here), has the ultimate goal of tracking down a single target for attack in the mechanism of drug abuse. This would give a critical “choke point” that could be used to develop anti-addiction drugs across more than addiction to a single substance. As well as benzodiazepines, this same mechanism is involved in use of marijuana and GBH – a synthetic “club drug.”
The target in this case is the neurotransmitter dopamine and the way it surges in response to drug taking. But that isn’t the end of the story. These surges, which are experienced as pleasure, also modify the way the neurons react to dopamine, in what is referred to as synaptic plasticity. It’s a case of sending a pleasurable message and then altering how such messages are received in the future. The “plasticity” here refers to a change in the neuron’s response to dopamine over time.
This explains why addiction takes time to develop. Despite the hype, a true physical addiction cannot happen with a single or even a few doses of a drug. There is an underlying growth of cells that has to happen before someone can be said to have a biological addiction. This isn’t true for the mental health use of the word, which may depend more on other factors, like obsession, or depression which drives the behavior.
The proof in this case comes from mice who were offered a choice of benzodiazepine laced sugar water or regular sugar water. Normal mice preferred the addictive type, while mice that had been genetically altered to change their receptors did not. Such “knock out” type experiments are very strong evidence that whatever is removed to make the addiction go away must be in the chain of cause for the addiction.