In a 10-year study by Biederman, et al. (2008), it was found that people with ADHD who took stimulant medication had neither a decreased or increased risk of substance abuse.  http://www.ncbi.nlm.nih.gov/pubmed/18316421 Biederman, J., Monuteaux, M.C., Spencer, T., Wilens, T.E., et al. (2008).  Stimulant therapy and risk for subsequent substance use disorders in male adults With ADHD: [...]