Figure 2 demonstrates visually that, as expected based on endorsement rates, ever use or endorsement of dependence symptoms for cocaine are more severe indicators of substance involvement (with ever use located approximately 2.0 standard deviations above the mean, and dependence symptoms located between 3.0 and 4.0 standard deviations above the mean), compared to either alcohol or marijuana (ever use of either of which is common, even among the community-sampled MTFS males and females). Similarly, as alcohol use and endorsement of dependence symptoms is far more common than endorsement of similar criteria for marijuana across all groups, these plots illustrate that individuals endorsing the same criteria represent a less extreme (that is, more normative) level of alcohol involvement (for which dependence symptoms are located between 0.5 and 2.5 standard deviations above the mean) compared to individuals endorsing similar criteria for marijuana (for which dependence symptoms are located between 2.5 and 3.5 standard deviations above the mean). These patterns reflect the “dependence liability” of each substance (e.g., alcohol dependence is “easier” to achieve than marijuana dependence). They do not capture differences in harm or treatment potential that may also vary between substances.
