We also recognize that dependence on one substance shows different characteristics from dependence on another, and it is valuable and necessary to study them as individual entities.
The proportions of subjects diagnosed with lifetime dependence on substances in each of the six categories – nicotine, alcohol, marijuana, cocaine, opiates or other drugs – are presented in Table 1.
The patients with the following conditions were excluded, including a history of head trauma, organic brain syndrome, psychosis or bipolar disorder, or dependence on substances other than alcohol and nicotine.
Dependence on substances other than alcohol, caffeine, and nicotine, as determined using the Structured Clinical Interview for DSM-IV-TR, and confirmed by urine toxicological screens, was one of the exclusion criteria for this trial.
Dependence on a substance happens when more and more of the substance is required to produce the desired effect.
You may wish to share the following definition (from The American Heritage Stedman's Medical Dictionary online at //www.answers.com/topic/addiction): "Addiction: habitual psychological and physiological dependence on a substance or practice beyond one's voluntary control".
Recently, the new psychiatric classification system DSM-V has for the first time categorized drug addiction vs behavioral addiction, and their central definition is dependence on a substance or activity.
When addiction advances we see physical dependence on the substance where the body experiences withdrawal when blood levels drop.
Almost half of the drug user sample also met criteria for dependence on another substance (45% opiates, 31% alcohol, and 14% cannabis).
