Additional links to content, to act as supplements in your studies and provide a broader scope of information.

Compton, W. M. & Volkow, N. D. (2006). Abuse of prescription drugs and the risk of addiction. Drug and Alcohol Dependence, 83, S4–S7.

Koob, G.F. & Volkow, N.D. (2010). Neurocircuitry of addiction. Neuropsychopharmacology, 35, 217–238.

Pisinger, C. & Døssing, M. (2014). A systematic review of health effects of electronic cigarettes.  Preventive Medicine, 69, 248–260.

Sinha, R. (2008). Chronic stress, drug use, and vulnerability to addiction. Annals of the New York Academy of Sciences, 1141, 105–130.

Stewart, J. (2000). Pathways to relapse: The neurobiology of drug- and stress-induced relapse to drug-taking. Journal of Psychiatry and Neuroscience, 25, 125–136.

Volkow, N.D., Wang, G.J., Fowler, J.S., Tomasi, D. et al. (2010). Addiction: decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain's control circuit. Bioessays, 32, 748–755.

Wise, R.A. & Koob, G.F. (2014). The development and maintenance of drug addiction. Neuropsychopharmacology, 39, 254–262.

The journal Nature, has provided a special issue that covers various aspects of addiction. The 10 brief papers and the video that appear at this site provide fascinating information regarding different aspects of the addiction process.
http://www.nature.com/nature/outlook/addiction/?WT.mc_id=TWT_NA_1406_ADDICITONSCIAM