Influence of Light Exposure on Cerebral MAO-A in Seasonal Affective Disorder and Healthy Controls Measured by PET

Study Overview
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Brief Summary
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This study aims to assess differences in monoamine oxidase A (MAO-A) distribution in the brain between seasonal affective disorder patients and healthy controls using positron emission tomography. In addition the investigators aim to demonstrate the impact of light therapy on MAO-A distribution In addition, a pilot study and a sub-study in healthy controls were performed

Detailed Description
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This study aims to assess differences in monoamine oxidase A (MAO-A) distribution in the brain between seasonal affective disorder patients and healthy controls using positron emission tomography. In addition, the investigators aim to demonstrate the impact of light therapy on MAO-A distribution by investigating patients and controls in the winter before bright light therapy, in the winter after bright-light therapy, and in the summer. Bright light therapy will be placebo controlled, randomized, and double blinded.

Official Title
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Influence of Light Exposure on Cerebral Monoamine Oxidase A in Seasonal Affective Disorder and Healthy Controls Measured by PET

Conditions
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Seasonal Affective Disorder

Intervention / Treatment
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* Other: Light Therapy
* Other: Placebo Light


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria for Patients: DSM-IV diagnosis of SAD established by diagnostic interview according to the SCID. Global Seasonality Score of 10 or higher on the Seasonal Pattern Assessment Questionnaire (SPAQ) Somatic health based on history, physical examination, ECG, and laboratory screening Aged 18 to 55 years No therapeutic treatment of SAD in the last 6 months (drugs and light therapy) Willingness and competence to complete the informed consent process Inclusion criteria for healthy controls: Aged 18 to 55 years Somatic and psychiatric health based on history, physical examination, ECG, laboratory screening, SCID Willingness and competence to complete the informed consent process Exclusion criteria for patients and healthy controls: Concomitant major medical or neurological illness Concomitant psychiatric disorders Current smoking Ingestion of antidepressants or other psychotropic agents targeting the serotonergic system, within the last 6 months. Bright light therapy within the last 6 months. Current substance abuse including alcohol, drugs of abuse, or any medication in a manner which is indicative of substance-related disorders (e.g. substance dependency) according to the DSM-IV. Failure to comply with the study protocol or follow the instructions of the investigators. Positive urine pregnancy test. For participants who participated in an earlier neuroimaging study using ionizing radiation, the total radiation exposure dose of 20 mSv over the last 10 years must not be exceeded, as specified in the legislation on radiation protection (Allg. Strahlenschutzverordnung 2010; www.ris.bka.gv.at).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Light Therapy<br>One subgroup of SAD patients and healthy controls respectively will receive bright light therapy using an artificial white light source (PhysioLight LD220 by DAVITA®, www.davita.de/shop/lichttherapiegeraete/lichtduschen-tageslicht/physiolight-ld-220.html) with full-spectrum 10.000lux light intensity. The treatment will be applied 30min per day at a distance of about of 50cm, preferably in the morning, during 3 weeks. | Other: Light Therapy<br>* One subgroup of SAD patients and healthy controls respectively will receive bright light therapy using an artificial white light source (PhysioLight LD220 by DAVITA®, www.davita.de/shop/lichttherapiegeraete/lichtduschen-tageslicht/physiolight-ld-220.html) with full-spectrum 10.000lux light intensity. The treatment will be applied 30min per day at a distance of about of 50cm, preferably in the morning, during 3 weeks.<br>|
| Placebo Comparator: Placebo Light<br>The second subgroup of the SAD patients and healthy controls will receive a non-biologically active light source (<400nm or >500nm). Here, the lamp will have largely similar shape and size as compared to the therapeutic device, but the fluorescent tube with the high light intensity will be replaced by an ordinary bulb. | Other: Placebo Light<br>* The second subgroup of the SAD patients and healthy controls will receive a non-biologically active light source (<400nm or >500nm). Here, the lamp will have largely similar shape and size as compared to the therapeutic device, but the fluorescent tube with the high light intensity will be replaced by an ordinary bulb.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in MAO-A specific distribution volume (MAO-A DVs) assessed with PET |  | PET2 (3 weeks after PET1) compared to PET 1 (baseline), PET3 (6 months after PET1) compared to PET 1 (baseline) and PET 2 (3 weeks after PET1) |