Dependence

Benzodiazepines are potentially addictive drugs: psychological and physical dependence can develop within a few weeks or months of regular or repeated use. There are several overlapping types of benzodiazepine dependence:

Therapeutic dose dependence

People who have become dependent on therapeutic doses of benzodiazepines usually have several of the following characteristics.

• They have taken benzodiazepines in prescribed "therapeutic" (usually low) doses for months or years.
• They have gradually become to "need" benzodiazepines to carry out normal, day-to-day activities.
• They have continued to take benzodiazepines although the original indication for prescription has disappeared.
• They have difficulty in stopping the drug, or reducing dosage, because of withdrawal symptoms.
• If on short-acting benzodiazepines they develop anxiety symptoms between doses, or get craving for the next dose.
• They contact their doctor regularly to obtain repeat prescriptions.
• They become anxious if the next prescription is not readily available; they may carry their tablets around with them and may take an extra dose before an anticipated stressful event or a night in a strange bed.
• They may have increased the dosage since the original prescription.
• They may have anxiety symptoms, panics, agoraphobia, insomnia, depression and increasing physical symptoms despite continuing to take benzodiazepines.

The number of people world-wide who are taking prescribed benzodiazepines is enormous. For example, in the US nearly 11 per cent of a large population surveyed in 1990 reported some benzodiazepine use the previous year. About 2 per cent of the adult population of the US (around 4 million people) appear to have used prescribed benzodiazepine hypnotics or tranquillisers regularly for 5 to 10 years or more. Similar figures apply in the UK, over most of Europe and in some Asian countries. A high proportion of these long-term users must be, at least to some degree, dependent. Exactly how many are dependent is not clear; it depends to some extent on how dependence is defined. However, many studies have shown that 50-100 per cent of long-term users have difficulty in stopping benzodiazepines because of withdrawal symptoms.

Prescribed high dose dependence

A minority of patients who start on prescribed benzodiazepines begin to "require" larger and larger doses. At first they may persuade their doctors to escalate the size of prescriptions, but on reaching the prescriber's limits, may contact several doctors or hospital departments to obtain further supplies which they self-prescribe. Sometimes this group combines benzodiazepine misuse with excessive alcohol consumption. Patients in this group tend to be highly anxious, depressed and may have personality difficulties. They may have a history of other sedative or alcohol misuse. They do not typically use illicit drugs but may obtain "street" benzodiazepines if other sources fail.

Recreational benzodiazepine abuse

Recreational use of benzodiazepines is a growing problem. A large proportion (30-90 per cent) of polydrug abusers world-wide also use benzodiazepines. Benzodiazepines are used in this context to increase the "kick" obtained from illicit drugs, particularly opiates, and to alleviate the withdrawal symptoms of other drugs of abuse (opiates, barbiturates, cocaine, amphetamines and alcohol). People who have been given benzodiazepines during alcohol detoxification sometimes become dependent on benzodiazepines and may abuse illicitly obtained benzodiazepines as well as relapsing into alcohol use. Occasionally high doses of benzodiazepines are used alone to obtain a "high".

Recreational use of diazepam, alprazolam, lorazepam, temazepam, triazolam, flunitrazepam and others has been reported in various countries. Usually the drugs are taken orally, often in doses much greater than those used therapeutically (e.g.100mg diazepam or equivalent daily) but some users inject benzodiazepines intravenously. These high dose users develop a high degree of tolerance to benzodiazepines and, although they may use the drugs intermittently, some become dependent. Detoxification of these patients may present difficulties since withdrawal reactions can be severe and include convulsions.

The present population of recreational users may be relatively small, perhaps one tenth of that of long-term prescribed therapeutic dose users, but probably amounts to some hundreds of thousands in the US and Western Europe, and appears to be increasing. It is a chastening thought that medical overprescription of benzodiazepines, resulting in their presence in many households, made them easily available and undoubtedly aided their entry into the illicit drug scene. Present sources for illicit users are forged prescriptions, theft from drug stores, or illegal imports.

Socioeconomic costs of long-term benzodiazepine use

The socio-economic costs of the present high level of long-term benzodiazepine use are considerable, although difficult to quantify. Most of these have been mentioned above. These consequences could be minimised if prescriptions for long-term benzodiazepines were decreased. Yet many doctors continue to prescribe benzodiazepines and patients wishing to withdraw receive little advice or support on how to go about it.

• Increased risk of accidents - traffic, home, work.
• Increased risk of fatality from overdose if combined with other drugs.
• Increased risk of attempted suicide, especially in depression.
• Increased risk of aggressive behaviour and assault.
• Increased risk of shoplifting and other antisocial acts.
• Contributions to marital/domestic disharmony and breakdown due to emotional and cognitive impairment.
• Contributions to job loss, unemployment, loss of work through illness.
• Cost of hospital investigations/consultations/admissions.
• Adverse effects in pregnancy and in the new-born.
• Dependence and abuse potential (therapeutic and recreational).
• Costs of drug prescriptions.
• Costs of litigation.