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

Exclusion Criteria

• •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).