Adolescence refers to the transition from childhood to adulthood that begins with the onset of puberty and ends with successful independence from the parent. A paradox for human adolescence is why, during a time when the individual is probably faster, stronger, of higher reasoning capacity and more resistant to disease, there is such an increase in mortality relative to childhood. These untimely deaths are not due to disease, but rather to preventable forms of death (accidental fatalities, suicide and homicide) associated with adolescents putting themselves in harm’s way due, in part, to diminished self control – the ability to suppress inappropriate emotions, desires and actions. This paper highlights how self control varies as a function of age, context and the individual and delineates its neurobiological basis.

There is a significant inflection in risk taking and criminal behavior during adolescence, but the basis for this increase remains largely unknown. An increased sensitivity to rewards has been suggested to explain these behaviors, yet juvenile offences often occur in emotionally charged situations of negative valence. How behavior is altered by changes in negative emotional processes during adolescence has received less attention than changes in positive emotional processes. The current study uses a measure of impulsivity in combination with cues that signal threat or safety to assess developmental changes in emotional responses to threat cues. We show that adolescents, especially males, impulsively react to threat cues relative to neutral ones more than adults or children, even when instructed not to respond. This adolescent-specific behavioral pattern is paralleled by enhanced activity in limbic cortical regions implicated in the detection and assignment of emotional value to inputs and in the subsequent regulation of responses to them when successfully suppressing impulsive responses to threat cues. In contrast, prefrontal control regions implicated in detecting and resolving competing responses show an adolescent-emergent pattern (i.e. greater activity in adolescents and adults relative to children) during successful suppression of a response regardless of emotion. Our findings suggest that adolescence is a period of heightened sensitivity to social and emotional cues that results in diminished regulation of behavior in their presence.

IMPORTANCEPosttraumatic stress disorder (PTSD) is a prevalent and serious mental health problem. Although there are effective psychotherapies for PTSD, there is little information about their comparative effectiveness. OBJECTIVE To compare the effectiveness of prolonged exposure (PE) vs cognitive processing therapy (CPT) for treating PTSD in veterans.

Drug and alcohol dependence affects millions each year. Adolescence is a period of increased risk for substance use disorders. Understanding how the brain is changing during this developmental window relative to childhood and adulthood and how these changes vary across individuals is critical for predicting risk of later substance abuse and dependence. This chapter provides an overview of recent human imaging and animal studies of brain development focusing on changes in corticostriatal circuitry that has been implicated in addiction. Behavioral, clinical, and neurobiological evidence is provided to help elucidate who may be most at risk for developing a substance abuse problem and whenthey may be most vulnerable.