Associations between gray matter volume, smoker status, and smoking heaviness

s / Drug and Alcohol Dependence 146 (2015) e118–e201 e197 evolving perceptions of POs versus heroin. Interview data were transcribed and content analyzed for key themes. Results:Mean age of PO-use initiation was 16.8 years. Most initiated PO use in a recreational context with high school peers as part of a poly-substance/poly-pharmaceutical use pattern. At the time of initiation, POs were viewed as safer, less stigmatized, and less addictive than illicit street drugs. Initiation was facilitated by ready, cost-free access to POs from household sources. As PO use escalated and, for many, opioid dependence developed, difficulties in accessing and affording enough POs to forestall withdrawal led 73% (32/44) to experiment with or transition to heroin use, typically via injection, within two years of PO initiation (mean age: 18.3 years). Of the 33 subjects who reported on treatment experiences, 76% (25/33) had received some treatment, most commonly methadone maintenance (36%; 12/33) and inpatient rehabilitation (30%; 10/33). Eighteen percent (6/33) report buying methadone or buprenorphine on the street for self-treatment. Conclusions: Results suggest that a subset of young adults who initiate nonmedical PO use as teens develop opioid dependence which can motivate them to seek more cost-effective means of maintaining their habits (i.e., transition to heroin and/or injection drug use). There is a pressing need to develop innovative prevention programs to help younger teens avoid initiating nonmedical PO use and to assist current PO users in preventing escalation to riskier forms of opioid use. Financial support: Supported by NIDA grant R01DA035146. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.450 Associations between gray matter volume, smoker status, and smoking heaviness Amanda R. Mathew1, Patrick McConnell1, Joseph McClernon2, Brett Froeliger1,2 1 Neurosciences, Medical University of South Carolina, Charleston, SC, United States 2 Department of Psychiatry and Behavioral Medicine, Duke University Medical Center, Durham, NC, United