The Effect of a Single Dose of Lamotrigine on Brain Function in Healthy Volunteers

Study Overview
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Brief Summary
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This study will test whether a single dose of Lamotrigine (300mg) exerts significant effects on emotional processing, cognitive ability and neural activity in healthy volunteers compared to placebo.

Detailed Description
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Glutamate has been implicated in the aetiology of mood disorders and there is current interest in developing novel agents targeting this system. However, the role of glutamate in human emotional function is relatively unknown. Lamotrigine's pharmacological profile involves a blockade of voltage-gated sodium channels, leading to an inhibition in the release of glutamate and resulting in a general inhibitory effect on cortical neuronal function. The current study plans to investigate the effects of modifying glutamate on emotional processing, cognitive function and neural activity. For this, 36 healthy volunteers will be recruited to the study and randomised to receive a single dose of lamotrigine (300 mg) or placebo. Two hours after drug administration, the effects of emotional processing via the use of cognitive tasks will be assessed using fMRI. This will be followed by an emotional test battery that will measure aspects of cognitive function as well.

Official Title
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The Effect of a Single Dose of Lamotrigine on Brain Function in Healthy Volunteers

Conditions
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Healthy

Intervention / Treatment
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* Drug: Lamotrigine
* Drug: Placebos


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female Aged 18-40 years Willing and able to give informed consent for participation in the study Sufficiently fluent English to understand and complete the task Exclusion Criteria: Current usage of psychoactive medication Current usage of the contraceptive pill Any past or current Axis 1 DSM-IV psychiatric disorder Significant medical condition Current pregnancy or breastfeeding Current or past history of drug or alcohol dependency Participation in a psychological or medical study involving the use of medication within the last 3 months Previous participation in a study using the same, or similar, emotional processing tasks Smoker > 5 cigarettes per day Typically drinks > 6 caffeinated drinks per day Takes folic acid supplements History of recurrent allergies and rashes Contraindication to MRI (e.g. claustrophobia and metallic implants)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Lamotrigine<br>Single dose of Lamotrigine (300mg - capsule). In healthy volunteers. | Drug: Lamotrigine<br>* Active Drug Capsule<br>|
| Placebo Comparator: Placebo<br>Placebo capsule: identical appearance to experimental capsule. In healthy volunteers. | Drug: Placebos<br>* Placebo Capsule<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neural function | fMRI resting state analysis | Data reporting and analysis to be completed within 1 year following study completion. | 
| Neural function | fMRI task analysis | Data reporting and analysis to be completed within 1 year following study completion. | 
| Neural function | fMRI checkerboard analysis | Data reporting and analysis to be completed within 1 year following study completion. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Emotional Processing and Cognitive Function | Analysis of recognition of emotion in faces (an Emotional Test Battery component) | Data reporting and analysis to be completed within 6 months following study completion. | 
| Emotional Processing and Cognitive Function | Speed of negative self-descriptor processing (an Emotional Test Battery component) | Data reporting and analysis to be completed within 6 months following study completion. | 
| Emotional Processing and Cognitive Function | Emotional memory analysis (an Emotional Test Battery component) | Data reporting and analysis to be completed within 6 months following study completion. | 
| Emotional Processing and Cognitive Function | Beck Depression inventory (BDI) questionnaire analysis | Data reporting and analysis to be completed within 6 months following study completion. | 
| Emotional Processing and Cognitive Function | Positive and negative affect schedule (PANAS) questionnaire analysis | Data reporting and analysis to be completed within 6 months following study completion. | 
| Emotional Processing and Cognitive Function | Stait-trait anxiety inventory (STAI) questionnaire analysis | Data reporting and analysis to be completed within 6 months following study completion. |