Stress- and cue-induced cigarette craving: effects of a family history of smoking.

Individuals with multiple smokers among first-degree relatives (FH+) are significantly more likely to be persistent smokers themselves. The mechanisms underlying this relationship are unknown. An independent line of research has suggested that persistent smoking is more common among smokers with heightened levels of cigarette craving after being exposed to smoking cues and stressors. The present study experimentally tested the hypothesis that FH+ smokers would exhibit stronger stress- and cue-induced craving reactions compared to FH- smokers. We also explored gender and ethnicity-related differences in these effects. To that end, 160 smokers were recruited by advertisement and exposed to neutral (changing a light bulb), stressful (dental work), and smoking (lighting up after a meal) situations, using script-guided imagery under controlled laboratory conditions. Participants completed craving questionnaires before and after each condition. Supporting the hypotheses, even after controlling smoking history and strength of habit, FH+ smokers (n=86) displayed stronger craving reactions to both dental and smoking imagery (p's<0.05) than FH- smokers (n=74). Interestingly, women had higher stress-, but not smoking cue-induced cravings, than men, with FH+ women exhibiting the highest levels of stress-induced craving. Findings suggest a mechanism through which a family history of smoking leads to poorer cessation success, especially among women.

Neural substrates underlying impulsivity.

Attention deficit hyperactivity disorder (ADHD) is a neuropsychiatric disorder whose three main symptoms are impulsiveness, inattention, and hyperactivity. Although ADHD is an early developmental disorder, it may persist into adulthood, resulting in deficits associated with poor academic performance, frequent job changes, poor and unstable marriages, and increases in motor vehicle accidents. Of the three primary symptoms of ADHD, deficits in impulse control are the most challenging to the social network and the judicial system. While the etiology of ADHD remains unknown, recent work suggests that the central deficits in ADHD may be due to poor response inhibition that is linked to monoamine and prefrontal lobe deficiencies. In the past, preclinical studies designed to understand the lack of impulse control have generally been relegated to studies linked to aggression and drug abuse. With the use of innovative noninvasive techniques, like anatomical and functional magnetic resonance imaging, selective neurochemical and behavioral paradigms have converged with preclinical reports and lend support to the premise that monoaminergic neurotransmitter systems and the cortico-striatal circuitry are essential to impulse control. Furthermore, new emerging data on neural substrates underlying impulsivity have incorporated brain regions involved in reinforcement, reward, and decision making such as the nucleus accumbens, cerebellum, and amygdala. As noninvasive brain imaging, neurochemical, and behavioral approaches are combined, our knowledge of the neural networks underlying impulsivity will hopefully give rise to therapeutic approaches aimed at alleviating this disorder.