New developments in human neurocognition: clinical, genetic, and brain imaging correlates of impulsivity and compulsivity.

Impulsivity and compulsivity represent useful conceptualizations that involve dissociable cognitive functions, which are mediated by neuroanatomically and neurochemically distinct components of cortico-subcortical circuitry. The constructs were historically viewed as diametrically opposed, with impulsivity being associated with risk-seeking and compulsivity with harm-avoidance. However, they are increasingly recognized to be linked by shared neuropsychological mechanisms involving dysfunctional inhibition of thoughts and behaviors. In this article, we selectively review new developments in the investigation of the neurocognition of impulsivity and compulsivity in humans, in order to advance our understanding of the pathophysiology of impulsive, compulsive, and addictive disorders and indicate new directions for research.

Differential effects of free versus imposed motor activity on alcohol consumption in C57BL/6J versus DBA/2J mice.

Practicing sport regularly provides obvious physiological and psychological benefits, but intensive sport activity, for example, at the competition level, may be associated with an increased risk for addictive disorder, whether to improve results (doping), to tolerate consequences of important pressure and physical activities (drugs), or developing as a substitute when stopping, definitely or temporally, this activity that has been considered as potentially addictive (conversion). An animal model of voluntary versus imposed physical activity is described in which males of two mouse strains with high (C57BL/6J) versus (DBA/2J) low alcohol preference were tested for possible modifications of alcohol consumption during and after physical activity, when the activity was forced versus when it was recreative. Free access to a running wheel allowed a moderate physical activity that was associated with a decrease in voluntary alcohol intake in C57BL/6J mice. On the one hand, forced running at a higher speed than that occurring under free conditions led to increased alcohol intake, back to the initial level. On the other hand, alcohol intake remained at the same low level whether or not DBA/2J mice were subjected to free or forced running. The only effect of forced running in these alcohol-avoiding mice was a significant desynchronization of circadian motor activity rhythm, which was even more pronounced than that induced in alcohol-preferring C57BL/6J mice. These results highlight the positive aspects of moderate and entertaining sport activity and provide further support to the idea that it can decrease spontaneous alcohol intake. They also tend to demonstrate that, at least for vulnerable subjects, forced and intensive activities may not have the same benefits regarding alcohol consumption.

Is DSM-IV bereavement exclusion for major depressive episode relevant to severity and pattern of symptoms? A case-control, cross-sectional study.

OBJECTIVE: To assess the DSM-IV major depressive episode (MDE) bereavement exclusion criterion by comparing severity and pattern of symptoms in bereavement-excluded individuals satisfying all other DSM-IV MDE criteria to these same variables in MDE controls. METHOD: A case-control, cross-sectional study of self-referred individuals seeking treatment for depressive symptoms was conducted. A total of 17,988 subjects met DSM-IV MDE symptom criteria. Of these, 1,521 individuals (8.5%) met all MDE criteria except the bereavement exclusion. They were matched by age, gender, marital status, and educational level with 1,521 MDE controls. Among the MDE controls, 292 had a recent bereavement and 1,229 did not. Severity of depression was measured by the number of MDE symptoms and the Montgomery-Asberg Depression Rating Scale (MADRS) score. Symptom cues of the bereavement-exclusion criterion were analyzed. The study was conducted between September 2003 and May 2004. RESULTS: Bereavement-excluded subjects were more severely depressed than MDE controls without bereavement and similar to MDE controls with bereavement. Two symptom cues, suicidal ideation and worthlessness, and the majority of other depressive symptoms were more pronounced in bereavement-excluded individuals than in MDE controls. CONCLUSIONS: Symptom cues of the DSM-IV MDE bereavement exclusion criterion should be modified since they could result in patients failing to be correctly diagnosed and treated.