In patients with drug abuse arising from an attempt to self-medicate (Khantzian 1985, 1997), treatment of the comorbid mental disorder may help prevent abuse. For instance, treatment of the preexisting condition of ADHD may prevent cocaine abuse (Biederman et al. 1995, 1997). In some cases though the persistent qEEG abnormalities associated with chronic SUD may happen to be independent from ADHD clinical status (Trudeau et al. 1999). The co-occurrence of ADHD and SUD has received considerable attention in the recent clinical and scientific literature (Davids et al. 2005). These two disorders are often linked to one another. Because the core symptoms of ADHD may be mimicked by the effects of psychoactive drugs, it is difficult to diagnose one disorder in the presence of the other (Davids et al. 2005). ADHD has been found to be associated with an earlier onset of SUD (Horner and Scheibe 1997). It is generally assumed that untreated ADHD is a risk factor for SUD development (Biederman et al. 1997, 1998; Manuzza et al. 1998; Trudeau 2005a, b).
