Physical dependence (or drug dependence) refers to a state resulting from habitual use of a drug, where negative physical withdrawal symptoms result from abrupt discontinuation. From the point of view of the dependent person, "dependence is duress," argues addiction researcher Griffith Edwards.

Symptoms

Increased heart rate and/or blood pressure, sweating, and tremors are common signs of withdrawal. More serious symptoms such as confusion, seizures, and visual hallucinations indicate a serious emergency and the need for immediate medical care. Alcohol, benzodiazepines, and barbiturates are the only commonly abused substances that can be fatal in withdrawal. Abrupt withdrawal from other drugs, such as opioids or psychostimulants, can exaggerate mild to moderate neurotoxic side effects due to hyperthermia and generation of free radicals, but life-threatening complications are very rare.

Treatment

Treatment for physical dependence depends upon the drug being withdrawn and often includes administration of another drug, especially for substances that can be dangerous when abruptly discontinued. Treatment usually requires the initiation and then tapering of a medication that has a similar action in the brain but a longer half-life.

Difference from addiction

Physical dependence is different from addiction. The latter is often characterized by a compulsive need for a drug, while the former is characterized by tolerance and withdrawal symptoms on discontinuing the use of a drug.

Drugs that cause physical dependence

• nicotine
• opioids
• barbiturates
• benzodiazepines
• ethyl alcohol (alcoholic beverage)
• GHB
• methaqualone (Quaalude)
• amphetamines
• caffeine
• cocaine
• anticonvulsants/mood stabilizers
• antipsychotics
• antidepressants

See also

• Addiction
• Addiction recovery groups
• Alcohol withdrawal syndrome
• Benzodiazepine withdrawal syndrome
• Discontinuation syndrome
• Rebound insomnia
• Substance dependence

References

External links

• National Institutes of Health MedlinePlus Encyclopedia
• Drugs causing physical dependence taken from Merck Manual of Diagnosis and Therapy, Section 15, Chapter 195" Merck Manual