Table 1.

Prevalence of symptom endorsement among individuals with DSM-IV opioid dependence (n = 2,120 cases)

DSM-IV symptom	n	%
Tolerance	2,031	95.80%
Withdrawal	2,095	99.34%
Longer than intended	1,315	89.21%
Attempt to quit	2,067	97.50%
Time spent	1,406	95.39%
Giving up activities	1,310	88.87%
Continued use	1,312	89.01%

Note: DSM-IV = Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.