2) reports that in a study of adolescents in Tennessee in publically funded substance abuse programs, over one-quarter of these teens had co-occurring mental or emotional disorders and 29 percent had previously taken medications for emotional or behavioral problems. The latter finding is an important fact because it supports the claim of existing mental/emotional disorders rather than the supposition that it was drug-taking which produced the psychological disturbance. Indeed, Heflinger reports that individuals with co-occurring mental or emotional disorders are sufficiently prevalent in all mental health and addiction service settings that they can be considered an expectation, rather than an exception.
Findings that emotional disorders are co-occurring with substance use and abuse is not the only argument that supports the notion that usage may be associated with a psychoemotional disturbance. Another fact that supports the claim is that some disorders are already well established as being associated with both initial substance use and continued use and/or abuse.
For example, Swendsen and Merikangas (2000) rep
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