Substance use disorder is a major public health problem worldwide. In the latest national study, the number of people over the age of 12 who are current cocaine users is estimated at 1.6 million, or 0.7% of the total population.  However, a safe, efficacious pharmacological treatment for cocaine addiction remains to be discovered.  Drug dependence is marked by high rates of relapse, which makes it particularly difficult to treat addicts. Research in the Behavioral Neurophysiology lab (BNL) focuses broadly on understanding the neuroadaptations that occur following cocaine and opiate drug self-administrationand how they contribute to relapse. Additional work focuses on how adolescent stress exposure can increase vulnerability to abuse drugs.