A Randomized Control Trial Employing fMRI to Investigate the Effects of Ketamine on Mentalizing and Metacognition in Healthy Volunteers
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 发起方
- 入组人数
- 70
- 试验地点
- 1
- 主要终点
- Changes in Mentalizing/Theory of Mind
研究概览
简要总结
Antipsychotic medication shows generally good effect sizes when looking at reduction of positive psychotic symptoms of schizophrenia, such as paranoia or delusion. However, social functioning often remains deficient in patients, meaning dopamine-receptor antagonists are not sufficient in treatment of people with schizophrenia.
A naturalistic video-based paradigm, named MASC has been used in the past to model over- and undermentalizing in patients with autism spectrum disorder and schizophrenia, since deficits in mentalizing can be explained by either overinterpreting a social situation (e.g. paranoid thoughts about intentions of others towards self) or by lacking the skill to read intentions of others.
To find out whether experimental manipulation via a non-competetive N-methyl-D-aspartate antagonist can induce difficulties with social cognition similar to those observed in people with schizophrenia, the investigators will conduct a RCT applying either ketamine or a placebo intravenously while participants are completing the above mentioned mentalizing task in the fMRI-scanner.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
盲法说明
All investigators (except anesthesiologists) are blinded until fMRI data has been preprocessed
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- 未提供
研究组 & 干预措施
Placebo
Participants receive a saline-solution intravenously
干预措施: Nacl 0.9% (Drug)
Ketamine
Participants receive ketamine (Plasma-level 100 ng/ml with an initial bolus administered as a 2 mg/ml solution)
干预措施: Ketamine (Drug)
结局指标
主要结局
Changes in Mentalizing/Theory of Mind
时间窗: During ketamine/placebo application in MRI
Over- and undermentalizing as characterized by the Movie for the assessment of social cognition (MASC). Higher scores on the "Mentalizing"-scale indicate better performance. Scores are divded between 4 scales (Mentalizing, No Mentalizing, Overmentalizing, Undermentalizing), each ranging from 0 to 27. Higher scores in one of the scales pertaining to "no Mentalizing, Overmentalizing or Undermentalizing mean a deficiency in mentalizing skills.
Neural response to ketamine/placebo during social cognition
时间窗: During ketamine/placebo application in MRI
fMRI imaging will be performed to measure blood oxygen level-dependent (BOLD) signal in response to mentalizing cues in the MASC-task under ketamine/placebo. BOLD-signal will be measured with T2-weighted images in a 3T MRI. Data will be analyzed using SPM 12 in MATLAB. Deviations in BOLD-activity under ketamine compared to placebo (higher or lower activity of certain voxels/clusters compared all other voxels in the brain) will mean a change in neural response due to the effect of the substance
次要结局
- Psychotic symptom load in PANSS-Questionnaire(10 minutes after cessation of MRI and ketamine/placebo application)
- Metacognitive-Questionnaire (MCQ)(20 minutes after cessation of MRI and ketamine/placebo application)
研究者
Rene Hurlemann
Professor for Psychiatry
University Hospital, Bonn