substance dependence

[DSM-IV] compulsive use of a substance despite significant problems resulting from such use. Although tolerance and withdrawal were previously defined as necessary and sufficient for dependence, they are currently only two of several possible criteria; others include taking the substance longer or in larger amounts than planned, repeatedly expressing a desire or attempting unsuccessfully to cut down or regulate use, and continuing use in the face of acknowledged substance-induced physical or mental problems. The term is sometimes used more narrowly to refer only to physiological dependence, and in this sense it may be considered to be a phenomenon distinct from tolerance. DSM-IV includes specific substance dependence disorders for alcohol, amphetamines or similarly acting sympathomimetics, cannabis, cocaine, hallucinogens, inhalants, nicotine, opioids, phencyclidines or similarly acting substances, and sedatives, hypnotics, or anxiolytics, as well as one for multiple substances (polysubstance). Called also chemical d. and drug d.