For the continuous variables reflecting severity of cocaine dependence, more days of cocaine use in the period of heaviest use was associated with older age; less education; being African-American; and a history of bipolar disorder, ASPD, and alcohol or opioid dependence (Table 2). Later age of first heavy cocaine use was associated with being older and unemployed, and with the absence of past opioid dependence. A greater number of lifetime cocaine dependence criteria (excluding withdrawal symptoms) was associated with a history of opioid, cannabis, alcohol, or sedative dependence. A greater number of lifetime cocaine withdrawal symptoms was associated with being female and with a history of cannabis, alcohol, or stimulant dependence.
