Reduced neural tracking of prediction error in substance-dependent individuals.

Objective: Substance-dependent individuals make poor decisions on the Iowa Gambling Task, a reward-related decision-making task that involves risk and uncertainty. Task performance depends on several factors, including how sensitive individuals are to feedback and how well they learn based on such feedback. A physiological signal that guides decision making based on feedback is prediction error.

Sex modulates approach systems and impulsivity in substance dependence.

Background: Personality traits such as pathological engagement in approach behaviors, high levels of impulsivity and heightened negative affect are consistently observed in substance dependent individuals (SDI). The clinical course of addiction has been shown to differ between sexes. For example, women increase their rates of consumption of some drugs of abuse more quickly than men.

Resting-state activity in the left executive control network is associated with behavioral approach and is increased in substance dependence.

Background: Individuals with drug addictions report increased willingness to approach rewards. Approach behaviors are thought to involve executive control processes and are more strongly represented in the left compared to right prefrontal cortex. A direct link between approach tendencies and left hemisphere activity has not been shown in the resting brain.

Negative reinforcement learning is affected in substance dependence.

Background: Negative reinforcement results in behavior to escape or avoid an aversive outcome. Withdrawal symptoms are purported to be negative reinforcers in perpetuating substance dependence, but little is known about negative reinforcement learning in this population. The purpose of this study was to examine reinforcement learning in substance dependent individuals (SDI), with an emphasis on assessing negative reinforcement learning.

Reduced cortical gray matter volume in male adolescents with substance and conduct problems.

Unlabelled: Boys with serious conduct and substance problems (Antisocial Substance Dependence (ASD)) repeatedly make impulsive and risky decisions in spite of possible negative consequences. Because prefrontal cortex (PFC) is involved in planning behavior in accord with prior rewards and punishments, structural abnormalities in PFC could contribute to a person's propensity to make risky decisions.

Methods: We acquired high-resolution structural images of 25 male ASD patients (ages 14-18 years) and 19 controls of similar ages using a 3T MR system.

Reducing HIV-related risk behaviors among injection drug users in residential detoxification.

This study of 632 drug injectors enrolled in eight residential detoxification centers within the National Drug Abuse Treatment Clinical Trials Network tested three interventions to reduce drug and sex risk behaviors. Participants were randomized to: (a) a two-session, HIV/HCV counseling and education (C&E) model added to treatment as usual (TAU), (b) a one-session, therapeutic alliance (TA) intervention conducted by outpatient counselors to facilitate treatment entry plus TAU, or (c) TAU. Significant reductions in drug and sex risk behaviors occurred for all three conditions over a 6-month follow-up period.

Do physicians referred for competency evaluations have underlying cognitive problems?

Purpose: Research suggests that there are concerns about the neuropsychological functioning of physicians who undergo physician competency evaluation. Academic health center faculty often participate in the evaluation and remediation of these physicians. The purpose of this study was to compare the cognitive abilities between a group of physicians referred for competency evaluations and a control group.

Brain activation during the Stroop task in adolescents with severe substance and conduct problems: A pilot study.

Background: Although many neuroimaging studies have examined changes in brain function in adults with substance use disorders, far fewer have examined adolescents. This study investigated patterns of brain activation in adolescents with severe substance and conduct problems (SCP) compared to controls.

Methods: Functional magnetic resonance imaging (fMRI) at 1.

Measuring impulsivity in adolescents with serious substance and conduct problems.

Adolescents with substance use and conduct disorders have high rates of aggression and attention deficit hyperactivity disorder (ADHD), all of which have been characterized in part by impulsivity. Developing measures that capture impulsivity behaviorally and correlate with self-reported impulsivity has been difficult. One promising behavioral measure, however, is a variant of the continuous performance test, the Immediate Memory Test/Delayed Memory Test (IMT/DMT).

A risk-taking "set" in a novel task among adolescents with serious conduct and substance problems.

Objective: Adolescent patients' conduct disorder and substance use disorder symptoms are "risky behaviors" with unpredictable rewards and punishments. The authors asked whether such youths also take excessive risks in new situations without prior learning, peer pressure, or intoxication.

Method: Subjects were 20 adolescent patients in a program treating conduct disorder and substance use disorder and 20 controls.

Reliable screening for neuropsychological impairment in multiple sclerosis.

In an earlier study, we developed the Multiple Sclerosis Neuropsychological Screening Questionnaire (MSNQ) to assist in the screening for neuropsychological (NP) impairments. Self-report MSNQ scores correlated significantly with measures of depression, whereas informant-report MSNQ scores correlated with cognitive performance, but not depression. This study was criticized for use of a small sample and lack of data regarding normal performance and test-retest reliability.