The fourth volume of this series features reviews that cover a range of subjects, with authorship from the United States and European Union. The likely inclusion of craving in the DSMV criteria for addiction confers special timeliness on the paper from Stephen Tiffany (-Update on Craving-). We can now look back on addiction therapeutics, in general, and on a clinically, and financially successful anti-addiction medication buprenorphine in the paper from Nancy Campbell and Anne Lovell. Marcus Munafo and colleagues provide an important emphasis on the ways socioeconomic status interacts with a...