Prevalence in Special Populations

A dramatically different pattern is found in surveys of drug abuse treatment facilities. Substance abuse treatment centers have reported that more than 20% of patients use benzodiazepines weekly or more frequently, with 30%— 90% of opioid abusers reporting illicit use (Iguchi et al. 1993 Stitzer et al 1981). Methadone clinics reported that high proportions ofurine samples are positive for benzodiazepines (Darke et al. 2003 Dinwiddle et al. 1996 Ross and Darke 2000 Seivewright 2001 Strain et al. 1991 Williams et al. 1996). The reasons for the high rates of benzodiazepine use in opioid addicts include self-medication of insomnia, anxiety, and withdrawal symptoms, as well as attempts to boost the euphoric effects of opioids. 

There is some evidence of a synergistic effect on reinforcement with concurrent administration of benzodiazepines and opioids (Walker and Ettenberg 2003). Cocaine abusers are less likely than opioid abusers to abuse benzodiazepines, preferring alcohol and opioids as secondary drugs of abuse. The most common pattern of benzodiazepine misuse in these individuals is intermittent use of therapeutic or supratherapeutic doses to counter unwanted effects of cocaine. 

Although estimates vary widely, approximately 10%-20% of individuals presenting for treatment of alcohol dependence may be using or abusing benzodiazepines (Ciraulo et al. 1988b Ciraulo et al. 2004 Johansson et al. 2003  

Lejoyeux et al. 1998). Similar to opioid-dependent persons, these patients reported that they use benzodiazepines to self-medicate anxiety, insomnia, and alcohol withdrawal and, less commonly, to enhance the effects of ethanol. Approximately l6%-25% of patients presenting for treatment of anxiety disorders abuse alcohol (Kushner et al. 1990 Otto et al. 1992). Controversy exists concerning appropriate benzodiazepine prescribing in this population (Cir-aulo and Nace 2000 Posternak and Mueller 2001). 

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