Benzodiazepine Dependence - Cause

Cause

Tolerance occurs to the muscle-relaxant, anticonvulsant, and sleep-inducing effects of benzodiazepines, and upon cessation a benzodiazepine withdrawal syndrome occurs. This can lead to benzodiazepines' being taken for longer than originally intended, as people continue to take the drugs over a long period of time to suppress withdrawal symptoms. Some people abuse benzodiazepines at very high doses and devote a lot of time to doing so, satisfying the diagnostic criteria in DSM IV for substance abuse and dependence. Another group of people include those on low to moderate therapeutic doses of benzodiazepines who do not abuse their benzodiazepines but develop a tolerance and benzodiazepine dependence. A considerable number of individuals using benzodiazepines for insomnia escalate their dosage, sometimes above therapeutically-prescribed dose levels. Tolerance to the anxiolytic effect of benzodiazepines has been clearly demonstrated in rats. In humans, there is little evidence that benzodiazepines retain their anti-anxiety effects beyond four months of continuous treatment; there is evidence that suggests that long-term use of benzodiazepines may actually worsen anxiety, which in turn may lead to dosage escalation, with one study finding 25% of patients escalated their dosage. Some authors, however, consider benzodiazepines to be effective long-term; however, it is more likely that the drugs are acting to prevent rebound anxiety withdrawal effects. Tolerance to the anticonvulsant and muscle-relaxing effects of benzodiazepines occurs within a few weeks in most patients.