Neuronal Correlates of Neurexan® Action in Mildly to Moderately Stressed Probands

Inclusion Criteria: 1. Male 2. Age between ≥31 to ≤59 years 3. Fluent in German language 4. Nonsmoker 5. Able to understand the explanations and instructions given by the study physician 6. Willing to adhere to the prohibitions and restrictions specified in this protocol 7. Healthy on the basis of clinical laboratory tests, physical examination, medical history, vital signs performed at Screening Visit 8. Magnetic Resonance Imaging (MRI) compatible 9. Participants must have signed a written informed consent document prior to any study procedure indicating that they understand the purpose of and procedures required for the study and are willing to participate in the study 10. Screening Scale for Chronic Stress of the Trier Inventory for Chronic Stress (TICS-SSCS) Score ≥ 9 and ≤ 36 11. Perceived Stress Scale (PSS) \> 9 Exclusion Criteria: 1. Current or past history of psychotic features or a diagnosis of any psychiatric disorder as defined in the Diagnostic and Statistical Manual of Mental Disorder 4th edition (DSM-IV) Axis I (recurrent major depression, panic disorder, social phobia, obsessive-compulsory disorder; alcohol dependency; schizophrenia and mania) 2. History of depressive episodes during the last 3 months prior to Screening Visit 3. Use of any psychotropic medication or suffering from severe psychiatric illness during the last 3 months prior to Screening Visit 4. Intake of prescription drugs for sleeping disorders or nervousness within one month prior to Screening Visit 5. Intake of over the counter (OTC) medication for the treatment of sleeping disorders or nervousness within the last (one) week prior to Screening Visit 6. High chronic stress as verified with the TICS-SSCS (\> 36) 7. Low chronic stress as verified with the TICS-SSCS (\< 9) and PSS ≤ 9 8. Participants with Blood Pressure (BP) ≥ 160/100 on day 0 and at randomization 9. Participants with treated hypertension 10. Known allergies and/or hypersensitivity to ingredients of Neurexan® (Passiflora incarnata, Avena sativa, Coffea arabica, Zincum isovalerianicum, lactose monohydrate, magnesium stearate) or Placebo (Lactose monohydrate, magnesium stearate) 11. Known Lactose intolerance 12. Use of any psychological stress-management intervention within the last 4 weeks prior to Screening Visit 13. History of substance, drug, including nicotine, or alcohol abuse within the preceding 3 months prior to Screening Visit 14. Alcohol, drug, nicotine intake within the last 24 hours before day 0 and at randomization - confirmed by positive screening tests 15. Body Mass Index (BMI) \> 30 kg/m2 16. Works regularly nights shifts 17. Serious, unstable illnesses including hepatic, renal, gastroenterologic, respiratory, cardiovascular, endocrinologic, neurologic, immunologic or hematologic disease as defined by clinical screening interview 18. Any somatic disease or other condition the Investigator or their duly assigned representatives believes could affect the ability of the individual to complete the study or the interpretation of the study results 19. Participants with medical illness that may have influenced brain morphology and/or physiology (e.g. uncontrolled hypertension, diabetes) 20. Participants with a history of one or more seizures without a clear and resolved aetiology 21. Participants with claustrophobia 22. Participants with tinnitus 23. Clinically significant acute illness within 7 days prior to randomization 24. Presence of metallic (ferromagnetic) implants (heart pacemaker, aneurysm clips), tattoos or piercings 25. Have received an experimental drug or used an experimental medical device (participation in any other clinical trial) within the last 30 days before study inclusion 26. Participants whose ability to speak for themselves lacks or can be doubted