Rajji Tarek K, Mulsant Benoit H, Nakajima Shinichiro, Caravaggio Fernando, Suzuki Takefumi, Uchida Hiroyuki, Gerretsen Philip, Mar Wanna, Pollock Bruce G, Mamo David C, Graff-Guerrero Ariel
Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Am J Geriatr Psychiatry. 2017 Jan;25(1):1-10. doi: 10.1016/j.jagp.2016.08.001. Epub 2016 Aug 2.
To assess the impact of reducing the dose of antipsychotics on cognition and dopaminergic D receptor availability in the whole striatum, and identify their relationship in patients with schizophrenia aged 50 years or older.
Open-label prospective PET [C]-raclopride study.
A tertiary care center outpatient setting.
Thirty-seven clinically stable participants with schizophrenia or schizoaffective disorder, aged 50 years or greater, and having been treated with olanzapine or risperidone monotherapy at the same dose for at least 6 months.
Gradual reduction in their olanzapine or risperidone daily dose of up to 40%.
Clinical and cognitive assessments, and [C]-raclopride PET to determine D receptor availability at baseline and after the dose reduction. Main outcome measures were overall cognition and D receptor availability in whole striatum.
Reducing the antipsychotic dose resulted in an increase in D receptor availability in the whole striatum and an association between D receptor availability and overall cognition despite lack of change in the latter. There was also an association between change in D receptor availability and change in overall cognition.
Our findings suggest that optimizing D receptor availability by reducing antipsychotic dose allows this system to contribute more significantly to cognitive function in patients with schizophrenia. This uncovered association could be harnessed by cognitive-enhancing interventions.
评估降低抗精神病药物剂量对50岁及以上精神分裂症患者全纹状体认知功能及多巴胺能D受体可用性的影响，并确定二者之间的关系。
开放标签前瞻性PET [C] -雷氯必利研究。
三级医疗中心门诊环境。
37名临床稳定的精神分裂症或分裂情感性障碍患者，年龄50岁及以上，且已接受奥氮平或利培酮单药治疗，且剂量相同至少6个月。
将奥氮平或利培酮的每日剂量逐渐降低高达40%。
临床和认知评估，以及[C] -雷氯必利PET，以确定基线和剂量降低后的D受体可用性。主要结局指标是全纹状体的整体认知和D受体可用性。
降低抗精神病药物剂量导致全纹状体D受体可用性增加，且尽管整体认知无变化，但D受体可用性与整体认知之间存在关联。D受体可用性变化与整体认知变化之间也存在关联。
我们的研究结果表明，通过降低抗精神病药物剂量优化D受体可用性可使该系统对精神分裂症患者的认知功能做出更显著贡献。这种新发现的关联可用于认知增强干预。
