Benzodiazepines: it's time to return to the evidence

When benzodiazepine anxiolytics were first introduced in the 1960s they were viewed as a liability-free alternative to barbiturates and meprobamate and were prescribed widely to patients with complaints of anxiety. After a decade of experience, it had become clear that benzodiazepines could be abused, and the pendulum began to swing towards suspicion of them. It is now commonly believed that they are dangerous drugs, prone to abuse and addiction. Treatment guidelines caution against their use as first-line or long-term therapy. It has become almost standard for clinical publications about benzodiazepines to issue warnings about dependence, abuse, addiction, tolerance or dangerousness, even when their central topic is an unrelated matter. Clinicians who advocate use of benzodiazepines may risk opprobrium from peers and institutions.

Terminology

The literature and diagnostic classifications such as the DSM and ICD use varying terminology when describing substance-use disorders. Here we differentiate between abuse (taking a drug to achieve an appetitive effect, or ‘high') and misuse (any use that deviates from the way a medication has been prescribed).

A reminder of what the evidence tells us

The bulk of scientific literature on benzodiazepine safety, dependence and misuse tells a different story. Although demonstrating a range of potential liabilities, including cognitive and psychomotor impairment, possible risk in pregnancy and severe and/or prolonged withdrawal syndromes, it does not confirm that these medications are primary drugs of abuse or gateway drugs leading to other substance abuse. The database was scrutinised in the 1980s and 1990s in a series of extensive reviews, including a volume commissioned and published by the American Psychiatric Association. In aggregate, they comprise over 2000 literature citations, dealing with both animal and human studies bearing on abuse, misuse and dangerousness of benzodiazepines.^1–3 Their authors conclude that benzodiazepines ‘do not strongly reinforce their own use and are not widely abused drugs. When abuse does occur, it is almost always among persons who are also abusing alcohol, opiates or other sedative hypnotics’² and that ‘epidemiological studies of various populations of drug abusers have often found rates of nonmedical use of benzodiazepines that exceed those found in the general population [but] the preponderance of the extensive use of benzodiazepines is directed by physicians for disorders in which these drugs have proven therapeutic effect’.³