Benzodiazepines (BZDs), or minor tranquilizers, are medications indicated for the short-term treatment of anxiety and insomnia. They also have other uses, such as muscle relaxants and antiepileptic agents.
Their main limitation in psychiatry is the attachment that people develop to these medications, for two reasons: their rapid effect on symptoms, and, for some BZDs, their potential to induce abuse/addiction.
Prolonged use of BZDs induces tolerance, meaning that their effects disappear and the person becomes susceptible, in the event of abrupt discontinuation, to a temporary syndrome with symptoms that are “opposite” to the effects of BZDs. Depending on the doses and potency involved, BZD withdrawal can produce severe mental disturbances beyond anxiety, including psychotic symptoms such as delusions, hallucinations, and disorientation in time and space. Because of the risk of major epileptic seizures, BZD withdrawal, like alcohol withdrawal—which is chemically similar—can be fatal.
In theory, BZDs should not be taken for long periods. In practice, anxious patients often become tolerant to them precisely because they take them regularly, relying on their initially beneficial effect on anxiety. The attachment is maintained psychologically even when the effect is no longer present, because a cyclical mechanism develops in which anxiety increases several hours after the last dose, and taking the next dose promptly brings the anxiety back to normal. These phenomena, known as micro-withdrawal, are simply the result of an imperfect transition between two successive doses, but they maintain the belief that the medication is still necessary to control anxiety, particularly when it is taken in the evening. Furthermore, the brain tends to remember the rapid initial effect all too clearly, so that even when that effect is no longer present, the first thought that occurs when anxiety appears is to take a BZD. People who have successfully tried other, more effective treatments for anxiety generally do not return to those medications when they relapse, but instead go back to BZDs.
In cases of discontinuation or recurrent micro-withdrawal, sometimes occurring several times a day, there are characteristic, although sometimes subtle, symptoms: alternation between drowsiness and nervousness/agitation, aggression, a state of heightened alertness, increased sensory perception with an unpleasant effect (blinding lights, colors that appear too vivid or “liquid,” the need to wear sunglasses, sounds that seem excessively intense, hypersensitivity to touch, and reduced tolerance of pain). Prolonged use of fast-acting BZDs creates a situation of “ups and downs” in their effects, with end-of-dose anxiety (the aforementioned micro-withdrawal) and a series of side effects associated with chronic intoxication: memory problems, impaired balance, slowed reflexes, muscle weakness and reduced exercise tolerance, muscle pain even at rest, irritability, and impulsivity (outbursts of anger, violent acts, destructive behavior).
There is currently no indication for long-term BZD treatment, except in certain treatment-resistant cases. BZD addiction can be treated with clonazepam initially in a maintenance regimen, which is the only systematic indication for long-term use of a BZD (clonazepam), according to the same principle as methadone in relation to heroin (not as a substitute, but as a way of normalizing the neurochemical system and the addictive behavior that has developed around it).
Using several BZDs together generally makes little sense. If they are short-acting BZDs, this is essentially equivalent to repeating doses of the same medication. If they have different durations of action, more than one BZD ends up circulating in the body, while they act on the same switch; therefore, either one works or the other does. In general, the one with the greatest affinity and the highest concentration will have the predominant effect.
BZD abuse and dependence have been extensively studied. People who abuse these medications generally resort to doses far higher than the initial doses (unlike people with straightforward anxiety, who continue to take the initial doses or only slightly higher ones). In general, people who abuse BZDs have had, or simultaneously have, a tendency to abuse other substances or alcohol (8 out of 10).
The risk of becoming dependent in the sense of developing drug addiction is related to several factors:
a) the duration and amount of the doses taken
b) the type of BZD
c) susceptibility to euphoric effects
Chemically similar BZDs can have very different addictive potential. This does not depend on potency or duration of effect, but rather on the speed at which the effect develops, especially when combined with moderate-to-high potency. Preparations with rapid release are therefore those that create the greatest risk of developing this type of attachment.
A person addicted to BZDs exhibits the same behaviors as a person addicted to other substances: they binge on BZDs, are unable to reduce their intake, deny the negative aspects of their use (chronic intoxication) or minimize them by attributing them to another cause; they try to obtain the substance through lies, forged prescriptions, “under-the-table” arrangements with accommodating doctors and pharmacists, or simply by persistently demanding and sometimes threatening healthcare professionals in order to obtain prescriptions or larger quantities of medication. Typically, they do not accept another BZD as a substitute, even if it lasts longer and is more potent, and continue using the BZD to which they are attached even when a sufficient dose of another BZD is administered to prevent withdrawal and block the effects of other BZDs taken simultaneously.
In the drug-dependent community, some benzodiazepines, but not others, circulate on the black market and are known as “psychiatric drugs,” because among the various drugs they are the ones officially sold as such.
Some products have been withdrawn from the market (flunitrazepam) because they were widely used as drugs of abuse, even as substances administered to unsuspecting victims in order to rob or sexually assault them. Other molecules are currently included in special controlled-drug schedules, which require non-repeatable prescriptions with limited validity, in order to discourage repeated prescribing without the patient being reassessed beforehand and to prevent indefinite use by patients who no longer see their doctor.