Dysphoria as it relates to addiction: 

 The article lacks a good description of the kinetics of Kappa opioid activation.  It is clear in numerous reports that animals avoid contexts that have been previously paired with Kappa agonists.  Human reports consistently describe "dysphoria" following Salvinorin use, followed by a rebound reward.  This all fits into the addiction session quite well, because the the first entry seemed poised to favor KOR agonism as a solution to addiction, however it seems unlikely that a drug addict would take such a substance when they already are likely to feel drug craving and withdrawal symptoms which are dysphoric.  The effects of KOR on dopamine are clear and robust and should be highlighted.  It would be nice to break the addiction paragraph up a bit to describe the dopamine effects, the behavioral effects, and the mechanisms for KOR in stress-induced behaviors, including reinstatement, anxiety, and depression-like models.  (The Dynorphin page for example does this quite nicely)