Antidepressants, Emotions and Personality: Comparing the Neuropsychological Effects of the Antidepressant Citalopram in Healthy Volunteers With High and Low Neuroticism
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 42
- 试验地点
- 1
- 主要终点
- Eye gaze fixations over the region of the eyes and whole face region of facial expressions during a gender discrimination task of emotional facial expressions
研究概览
简要总结
Neuroticism is a personality trait described as an enduring tendency to experience negative emotional states and to respond poorly to environmental stress. It has been shown that high neuroticism can predispose, amongst other factors, to the development of depressive episodes. Recent studies suggest that subjects with high neuroticism have a different response to stimuli with an emotional content, showing both decreased processing of positive or increased processing of negative emotionally salient cues. These differences in cognitive processing of emotional stimuli are believed to underpin the psychological characteristics that link high neuroticism with a higher risk for depression.
Preliminary data also indicate that modulation of serotonin function by antidepressant treatment in healthy volunteers with high neuroticism traits could modify the brain activity associated with the processing of emotional stimuli that is dysfunctional in this vulnerable population.
The aim of this research is to investigate further whether modulation of serotonin function via administration of serotonergic antidepressants (SSRIs) can revert the dysfunctional emotion processing that characterises subjects with the personality trait of high neuroticism.
In particular we hypothesise that SSRI administration will modify the abnormal patterns in attention, physiological reactivity and regulation of emotional stimuli present in healthy individuals with the vulnerable personality trait of high neuroticism.
Carrying out this research on healthy volunteers will enable us to understand if modulating serotonin function by antidepressant administration has an effect not only on mood symptoms - as is evident in depressed patients - but also on the predisposing psychological and cognitive processes that sustain the depressed mood, such as the response to emotional stimuli. We will also be able to verify if this effect is shown early treatment and prior to any subjective changes in mood. This will be done by administering seven days of either the antidepressant citalopram or placebo to subjects with high neuroticism scores and then comparing them on a series of computer based psychological tests measuring various aspects of how emotionally salient stimuli are processed.
详细描述
Forty healthy volunteers with high scores on the Eysenck Personality Questionnaire Neuroticism scale will be recruited from the general population using posters and advertising in local newspapers and on internet. All advertisement will direct volunteers to a specific website (http://weblearn.ox.ac.uk/site/users/psyc0390/public/) (hosted in the Weblearn area of the University of Oxford) that will report the study Information Sheet. People clicking on the "I agree to participate" link will then be able to leave their contact details and fill in a shortened version of the Eysenck Personality Questionnaire. Questionnaire results will be anonymous and only the researcher will access the data and the correspondent contact details. Thus, only volunteers consenting to participate to the full study will be screened for neuroticism scores and only suitable ones will be contacted for the screening visit.
Participants will be requested to come to the Department of Psychiatry of the University of Oxford for an initial screening assessment including basic medical examination and structured psychiatric interview. On that occasion they will also be asked to complete a number of questionnaires such as Beck Depression Inventory, Dysfunctional Attitudes Scale, State-Trait Anxiety Inventory, Eysenck Personality Questionnaire, Parental Bonding Instruments and Life Events Rating Scale.
Volunteers will be randomized to receive citalopram or placebo in a double blind between groups design for 7 days. They will receive the treatment capsules to take home and will be instructed to take the capsule every morning after breakfast around 8 am. Subjective mood will be assessed on each day of treatment using the Befindlichskeit scale of mood and energy, the State Anxiety Inventory and Visual Analogue Scales. Side-effects will be registered every day using a specific side-effects report sheet.
On the day before starting the treatment (Day 0) and on the last day of treatment (Day 7) participants will be asked to collect saliva sample to measure cortisol levels. Collection of samples will be performed by participants in their own home and is non-invasive. Participants will be provided with appropriate collection vessels containing a cotton swab. They will be asked to roll this swab around in their mouths for a minute after waking and take 4 further samples at 15 minute intervals, each on a separate cotton swab. The cotton swabs will be put back in the collection vessel and participants will be asked to store their saliva samples in the freezer and bring them back to the researcher on the day of testing.
Participants will be given the mobile phone number of the Principal Investigator (PI) so that they can immediately get in contact if they have any concerns when taking the drug. In addition, the researcher will contact participants within the first few days to ensure that they are not experiencing any side effects. Participants experiencing more than mild transient side effects will be advised to stop taking the drugs and will be withdrawn from the study.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Participant is willing and able to give informed consent for participation in the study.
- •Male or Female, aged 18 - 50 years
- •Eysenck Personality Questionnaire Neuroticism scale ≥15/24
- •Fluent in English language (in order to understand all study instructions and tasks using verbal stimuli)
排除标准
- •any significant medical condition
- •current or past history of psychiatric disorder
- •family history of mania
- •pregnancy or breastfeeding
- •taking any current medication (except the contraceptive pill)
- •having taken part in other trials involving psychotropic drug intake in the previous three months
研究组 & 干预措施
Citalopram
20 mg citalopram capsule, 1/ day, after breakfast (approximately 8am), for 7 days
干预措施: Citalopram (Drug)
Placebo
Placebo capsule 1/ day, after breakfast (approximately 8am), for 7 days
干预措施: Placebo (Drug)
结局指标
主要结局
Eye gaze fixations over the region of the eyes and whole face region of facial expressions during a gender discrimination task of emotional facial expressions
时间窗: Day 7 of treatment administration
Fixations were defined as a set of eye positions within a defined area for a selected amount of time. We adopted the default values defining a fixation to be within a 0.30 x 0.30 degree box for 100 ms and calculating fixations using a velocity/distance algorithm. In the calculation, subjects' eyes are allowed to drift during fixation as long as the amount of drift is less than this area per 100 ms. We calculated the number of fixations present within the Region of Interest (ROI) of the eyes of the facial expressions used as stimuli in the task.
次要结局
- Scanpath length over the eye region and whole face region of facial expressions during a gender discrimination task of emotional facial expressions(Day 7 of treatment)
- Scanning time over the eyes region and whole face of facial expressions during a gender discrimination task of emotional facial expressions(Day 7 of treatment)
- Gaze maintenance over the eyes region and whole face of facial expressions during a gender discrimination task of emotional facial expressions(Day 7 of treatment)
- Accuracy and reaction time of emotional facial expressions recognition during a facial expressions recognition task(Day 7 of treatment)
- Recall and recognition scores and reaction times during a memory task for emotionally valenced self-descriptors(Day 7 of treatment)
- Eye-blink reflex magnitudes in response to pleasant, unpleasant and neutral pictures during an emotion potentiated startle task(Day 7 of treatment)
- High Frequency Heart Rate Variability (HF-HRV) during an emotion regulation task of unpleasant pictures(Day 7 of treatment)
- Affect ratings during an emotion regulation task of unpleasant pictures(Day 7 of treatment)
研究者
Martina Di Simplicio
Dr
University of Oxford