ADHD and AOD use frequently co-occur, and there is evidence to suggest that the presence of ADHD is a primary risk factor for the development of AOD use disorders [872, 873]. Research suggests that untreated ADHD is associated with a more problematic course of AOD use disorder, with clients less likely to gain benefits from treatment, adhere to treatment, and achieve and maintain abstinence [874–876]. ADHD is also associated with an earlier age of first substance use, higher rates of poly-substance use, greater substance dependence, and increased risk of relapse [873, 877–879]. However, evidence suggests that responding early to ADHD through the provision of appropriate evidence-based treatments can prevent the development of AOD use disorders among adolescents, and reduce the risk of AOD relapse among adults [877, 880].
Difficulties can be faced when assessing and screening for the presence of co-occurring ADHD, as symptoms can be masked or even resemble those of intoxication or withdrawal (see Chapter A4) [878, 881, 882]. Although some experts recommend an abstinence period of one month or more to assist with diagnosis [102, 883, 884], this strategy is not supported by the broader evidence base, or the majority of experts [883, 885–887].
To assist with clinical decision making, it may be useful to involve family members or friends, who can provide further information and clarification regarding the presence of attention problems, impulsivity, and restlessness over the person’s lifetime [884].