This refers to a state in which normal physical or mental functioning requires the continued presence of a substance. When the substance is reduced or stopped, withdrawal symptoms may occur. Dependence can be physical, involving tolerance and withdrawal, or psychological, involving strong emotional or mental urges to continue using the substance.
The term, introduced by the World Health Organization (WHO) in 1964 to replace “addiction” and “habituation,” describes a condition where drug use becomes a high priority and is continued despite harmful consequences.
A person may be dependent without being addicted, but dependence can often progress to addiction if control over use becomes impaired.
Sources: UPenn; SAMHSA_NCBI; Recovery Research Institute; UNODC; HRB