Safety out of control: dopamine and defence

We enjoy a sophisticated understanding of how animals learn to predict appetitive outcomes and direct their behaviour accordingly. This encompasses well-defined learning algorithms and details of how these might be implemented in the brain. Dopamine has played an important part in this unfolding story, appearing to embody a learning signal for predicting rewards and stamping in useful actions, while also being a modulator of behavioural vigour. By contrast, although choosing correct actions and executing them vigorously in the face of adversity is at least as important, our understanding of learning and behaviour in aversive settings is less well developed. We examine aversive processing through the medium of the role of dopamine and targets such as D2 receptors in the striatum. We consider critical factors such as the degree of control that an animal believes it exerts over key aspects of its environment, the distinction between 'better' and 'good' actual or predicted future states, and the potential requirement for a particular form of opponent to dopamine to ensure proper calibration of state values

Polysubstance Use Among Minority Adolescent Males Incarcerated for Serious Offenses

BACKGROUND: Adolescent juvenile offenders are at high risk for problems associated with drug use, including polysubstance use (i.e., use of a variety of drugs). The combination of juvenile offending and polysubstance use presents a significant public and child health concern. OBJECTIVE: This study explored polysubstance use among a sample of youth incarcerated for serious offenses. We examined several risk factors for substance use and delinquency (i.e., early and frequent substance use, prior history of arrests, school expulsion, Black ethnicity), as well as the association between aggression and polysubstance use. METHODS: Data were collected via questionnaires from 373 serious male juvenile offenders upon intake into a secure locked facility. Youth were on average 16 years old, and minority youth were overrepresented (28.1% Black, 53.1% Latino). Poisson regressions were used to assess the associations between the risk factors, aggression, and polysubstance use. RESULTS: Consistent with the literature, Black youth reported less polysubstance use and later age of drug use onset than White and Latino youth. Findings suggest that Latino juvenile offenders and those with an early and problematic pattern of substance use are at heightened risk for polysubstance use. Aggression was not significantly related to polysubstance use, over and above the risk factors. CONCLUSIONS: Given that Latino youth experience low rates of treatment for substance use, the development of culturally-sensitive interventions for these youth is needed. Interventions should also be multifaceted to address the multitude of risk factors associated with polysubstance use among juvenile offenders