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    ABSTRACT: Impulsivity has been repeatedly identified as a major problem in schizophrenia. The literature revealed several ways of defining and conceptualizing impulsivity as well as a variety of measures and an analysis of the consequences of impulsivity. Thus, we review the lack of agreement in the conceptualization and measurement of impulsivity. We also review the latest evidence that impulsivity may have an important role in the etiology of substance use, aggression, violence, and suicide in schizophrenia. In addition, we outline the recent findings in neuroimaging research to elucidating the neurobiological deficits underlying pathological impulsivity in schizophrenia.
    Aggression and Violent Behavior 11/2012; · 1.95 Impact Factor
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    ABSTRACT: Several prospective studies in the general population [1–5] and meta-analyses [6–7] have consistently found that cannabis use is associated with an increased risk of psychotic disorders, in particular schizo-phrenia. Continued cannabis use over time increases the risk of psychosis in a dose–response fashion [3–5]. A higher risk of schizophrenia is predicted by an earlier age of cannabis use [1,6–7]. Several hypotheses have been suggested to explain the association between canna-bis use and schizophrenia, including the following [6,8]: ƒ Cannabis use is a causal factor for schizophrenia; ƒ Cannabis use precipitates psychosis in vulnerable people; ƒ Cannabis use exacerbates symptoms of schizophrenia; ƒ Patients with schizophrenia are more liable to become regular cannabis users, including during the prodromal phase. Ferdinand et al. investigated the role of pre-existing self-reported psychotic symp-toms and found a bidirectional association between cannabis and psychotic symptoms in a 14-year follow-up study in the general population [9]. They showed that cannabis use in individuals who did not have psy-chotic symptoms before they began using cannabis predicted later psychotic symp-toms and that the reverse was also true, in that psychotic symptoms in those who had never used cannabis before the onset of psychotic symptoms also predicted future cannabis use. However, in a recent 10-year follow-up study, Kuepper et al. clarified the tempo-ral association between cannabis use and psychotic experiences by systematically For reprint orders, please contact: reprints@futuremedicine.com
    Neuropsychiatry 06/2011; 1(3):203-207.
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    ABSTRACT: Impulsive risk-taking contributes to deleterious outcomes among clinical populations. Indeed, pathological impulsivity and risk-taking are common in patients with serious mental illness, and have severe clinical repercussions including novelty seeking, response disinhibition, aggression, and substance abuse. Thus, the current study seeks to examine self-reported impulsivity (Barratt Impulsivity Scale, BIS-11) and performance-based behavioral risk-taking (Balloon Analogue Risk Task, BART) in bipolar disorder and schizophrenia. Participants included 68 individuals with bipolar disorder, 38 with schizophrenia, and 36 healthy controls. Self-reported impulsivity was elevated in the bipolar group compared with schizophrenia patients and healthy controls, who did not differ from each other. On the risk-taking task, schizophrenia patients were significantly more risk-averse than the bipolar patients and controls. Aside from the diagnostic group differences, there was a significant effect of antipsychotic (AP) medication within the bipolar group: bipolar patients taking AP medications were more risk-averse than those not taking AP medications. This difference in risk-taking due to AP medications was not explained by history of psychosis. Similarly, the differences in risk-taking between schizophrenia and bipolar disorder were not fully explained by AP effects. Implications for clinical practice and future research are discussed.Neuropsychopharmacology accepted article preview online, 21 August 2013. doi:10.1038/npp.2013.218.
    Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 08/2013; · 8.68 Impact Factor