Assessing teen risk behavior and later drug use

Gemstone Team Risky Business

Effect of Addiction Modeling Reinforcement Schedules on Delay Discounting

Elevated delay discounting, in which delayed rewards quickly lose value as a function of time, is associated with substance use and abuse. Currently, the direction of causation is unclear: while some research indicates that elevated delay discounting leads to future substance use, it is also possible that chronic substance use and specifically the rate of reinforcement associated with drug use, leads to elevated delay discounting. This project aims to examine the latter possibility. 47 participants completed ten 30-minute daily sessions of a visual attention task, and were reinforced at a rate intended to model drug use (fixed ratio 1) or drug abstinence (fixed ratio 10). Baseline and post-training rates of delay discounting were assessed for hypothetical $50 and $1000. Area under the curve of the indifference points as a function of delay was calculated. A greater area under the curve suggests more self-control, whereas a lower value represents more impulsiveness. Results at the monetary value of both $50 and $1000 showed increased impulsivity in relation to the control for both the FR1 and FR10 groups indicating that the two schedules may both model drug use.

Sick Boy

This poetry collection explores the concepts of addiction and redemption. It does so through a series of vignette-style poems set in the Baltimore and DC area at the height of the heroin epidemic in the United States. Split into three parts, the first addresses the narrator’s initial drug use, the second follows the narrator at the strongest and least hopeful point of his addiction, and the third examines, through various scenes, the narrator’s attempts to find a life free from the confines of addiction. Although dealing with subject matter derived from dark and unfortunate circumstances, the narrator’s heroin addiction serves merely as a catalyst for the various situations that force the narrator to develop emotionally and grow even when trapped in the seemingly inescapable confines of addiction.

Gender, Behavioral Assessment of Negative Reinforcement Driven Risk Taking Propensity, and Cigarette Smoking

Cigarette smoking remains the leading preventable cause of death and disability in the United States and most often is initiated during adolescence. An emerging body of research suggests that a negative reinforcement model may explain factors that contribute to tobacco use during adolescence and that negative reinforcement processes may contribute to tobacco use to a greater extent among female adolescents than among male adolescents. However, the extant literature both on the relationship between negative reinforcement processes and adolescent tobacco use as well as on the relationship between gender, negative reinforcement processes, and adolescent tobacco use is limited by the sole reliance on self-report measures of negative reinforcement processes that may contribute to cigarette smoking. The current study aimed to further disentangle the relationships between negative reinforcement based risk taking, gender and tobacco use during older adolescence by utilizing a behavioral analogue measure of negative reinforcement based risk taking, the Maryland Resource for the Behavioral Utilization of the Reinforcement of Negative Stimuli (MRBURNS). Specifically, we examined the relationship between pumps on the MRBURNS, an indicator of risk taking, and smoking status as well as the interaction between MRBURNS pumps and gender for predicting smoking status. Participants included 103 older adolescents (n=51 smokers, 50.5% female, Age (M(SD) = 19.41(1.06)) who all attended one experimental session during which they completed the MRBURNS as well as self-report measures of tobacco use, nicotine dependence, alcohol use, depression, and anxiety. We utilized binary logistic regressions to examine the relationship between MRBURNS pumps and smoking status as well as the interactive effect of MRBURNS pumps and gender for predicting smoking status. Controlling for relevant covariates, pumps on the MRBURNS did not significantly predict smoking status and the interaction between pumps on the MRBURNS and gender also did not significantly predict smoking status. These findings highlight the importance of future research examining various task modifications to the MRBURNS as well as the need for replications of this study with larger, more diverse samples.

Drug Delivery through the Blood-Brain Barrier through Use of Vascular Cell Adhesion Molecule 1- Targeted Nanoparticles

The blood brain barrier (BBB) is a semi-permeable membrane separating the brain from the bloodstream, preventing many drugs that treat neurological diseases, such as Alzheimer’s and Parkinson’s, from reaching the brain. Our project aimed to create a novel drug delivery system targeting the brain during neural inflammation. We developed a cationic solid lipid nanoparticle (CSLN) complex composed of cationic nanoparticles, biotin, streptavidin, and anti-vascular cell adhesion molecule-1 (anti- VCAM-1) antibodies. The anti-VCAM-1 antibody is used to target VCAM-1, a cell adhesion protein found on the BBB endothelium. VCAM-1 expression is elevated in the presence of inflammatory molecules, such as tumor necrosis factor-alpha (TNF- α). Through the use of a simple BBB model, results showed that our novel drug delivery system experienced some level of success in targeting the brain inflammation due to increasing TNF-α concentrations. This is promising for drug delivery research and provides support for VCAM-1 targeting using more robust and complex BBB models.