(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.
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
, can exaggerate mild to moderate neurotoxic
side effects due to hyperthermia
and generation of free radicals
, but life-threatening complications are very rare.
Treatment for physical dependence depends upon the drug being withdrawn and often includes administration of another drug, especially for substances that can be dangerous when abruptly discontinued.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