The importance of distinguishing between dependence and addiction in the context of long-term benzodiazepine use

To the Editor

When patients see a general medical practitioner or psychiatrist or attend a hospital emergency department for anxiety-related problems and the accompanying sleep disturbance, they are often prescribed sedating second-generation antipsychotics such as quetiapine. This is commonly done to avoid prescribing benzodiazepines because of their ‘addictive’ potential. Such practice is based on an assumption that second-generation antipsychotics are safer than benzodiazepines, despite the well-documented burden of adverse effects of the former class of medications.

Unfortunately, the latest Royal Australian and New Zealand College of Psychiatrists guidelines for the use of benzodiazepines in psychiatric practice (available at https://www.ranzcp.org/Files/Resources/College_Statements/Practice_Guidelines/pg5-pdf.aspx) perpetuate a notion that long-term benzodiazepine use is dangerous and that it may be considered only when everything else fails. Thus, the guidelines state that ‘longer term use should only be considered in patients who do not respond to adequate trials of other evidence-based pharmacological and psychological treatments’. Although authors of the guidelines should be commended for not suggesting that addiction is a direct consequence of long-term benzodiazepine use, they do not do enough to clarify the distinction between dependence and addiction in this context. For example, they state that ‘patients should be advised that benzodiazepines may produce both tolerance and dependence, with the risk of withdrawal symptoms’.

Several studies (reviewed by Starcevic, 2014) have demonstrated that dose escalation (i.e. tolerance) occurs rarely during a long-term treatment of anxiety disorders with benzodiazepines. In contrast, withdrawal symptoms after an abrupt cessation of long-term benzodiazepine use or precipitous decrease in the dose of benzodiazepines are common, although not inevitable; patients should be rightly cautioned about them, but not intimidated. The important point here is that pharmacological dependence (characterised by tolerance and/or withdrawal symptoms) denotes no more than a normal physiological adaptation to the long-term presence of a substance that affects the central nervous system (O’Brien et al., 2006) and that it is erroneous to consider as addicted all individuals who are dependent on benzodiazepines.

Substance addiction is a compulsive drug-seeking behaviour, associated with craving and loss of control, which persists despite multiple adverse consequences (Shaffer, 1999). Addiction-like pattern of benzodiazepine use is rarely seen among patients with anxiety disorders who do not have another substance use disorder (Starcevic, 2014). Therefore, withholding benzodiazepines from such patients on the grounds that they cause addiction and substituting them for medications that may be more harmful represents poor clinical practice.