title: The effect of clozapine and risperidone on attentional bias in patients with schizophrenia and a cannabis use disorder: An fMRI study.
abstract: Cannabis use disorders (CUDs) are highly comorbid in patients with schizophrenia and are associated with poor outcome. Clozapine has been put forward as the first choice antipsychotic in this comorbid group. However, little is known about the mechanisms underlying the assumed superiority of clozapine. We compared the effects of clozapine and risperidone on attentional bias, subjective craving and associated regional brain activity in patients with schizophrenia and CUD. Overall, 36 patients with schizophrenia and 19 healthy controls were included. Patients were randomised to antipsychotic treatment with clozapine or risperidone. At baseline and after 4 weeks of medication use, regional brain responses were measured during a classical Stroop and a cannabis word Stroop using functional magnetic resonance imaging. Clozapine-treated CUD patients showed a larger reduction in craving and in activation of the insula during the cannabis word Stroop, while risperidone-treated patients showed a larger decrease in activation of the right anterior cingulate cortex during the classical Stroop. A significant association was found between decreases in subjective craving and decreases in insula activation during the cannabis word Stroop. These findings strongly suggest that clozapine may be a better treatment choice in patients with schizophrenia and CUD than risperidone.
authors.affiliation: Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands m.w.machielsen@amc.nl.
authors.forename: Marise Wj
authors.initials: MW
authors.lastname: Machielsen
authors.affiliation: Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Veltman
authors.affiliation: Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
authors.affiliation: Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Lieuwe
authors.initials: L
authors.lastname: de Haan
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000070379:Attentional Bias / Q000187:drug effects*; D001931:Brain Mapping / Q000379:methods*; D003024:Clozapine / Q000009:adverse effects / Q000627:therapeutic use*; D066249:Craving / Q000187:drug effects; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D002189:Marijuana Abuse / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000523:psychology; D009426:Netherlands; D011237:Predictive Value of Tests; D018967:Risperidone / Q000009:adverse effects / Q000627:therapeutic use*; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D057190:Stroop Test; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D003024:Clozapine; D018967:Risperidone
keywords: Cannabis; addictive behaviour; antipsychotic agents; clozapine; functional magnetic resonance imaging; risperidone; schizophrenia