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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
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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: Substance use disorders (SUDs) are common in patients with schizophrenia and this comorbidity is associated with a poorer prognosis, relative to non-abusing patients. One hypothesis that has been advanced in the literature is that dual diagnosis (DD) patients may have a different personality profile than non-abusing schizophrenia patients. The present case-control study aimed to characterize levels of personality traits (sensation-seeking, social anhedonia, and impulsivity) in substance abuse/dependence patients with (DD group; n=31) and without schizophrenia (SUD group; n=39), relative to non-abusing schizophrenia patients (SCZ group; n=23), and healthy controls (n=25). Impulsivity was assessed using the Barratt Impulsivity Scale. Sensation-seeking was assessed using the Zuckerman Sensation Seeking Scale. Social anhedonia was assessed with the Chapman Social Anhedonia Scale. We found that sensation-seeking was significantly higher in DD and SUD, relative to SCZ patients. We found that social anhedonia was significantly elevated in DD and SCZ, relative to healthy controls. We found that impulsivity was significantly higher in DD, SCZ and SUD patients, compared to healthy controls. The results suggest that sensation-seeking is prominent in substance abuse/dependence (irrespective of schizophrenia), social anhedonia is prominent in schizophrenia (irrespective of substance abuse/dependence), and impulsivity is prominent in all three populations.
    Psychiatry research. 09/2012;