definiens: shall mean a selective serotonin reuptake inhibitor, which is a substance that acts at a synapse by inhibiting or preventing the reuptake of serotonin ( S - hydroxy - tryptamine ), " 5HT1 A Partial Agonisf shall mean a substance that elicits a lower maximal response of the SHT1A receptor, when compared to an equal concentration of serotonin, and " Dual SSRI / S - HT1 A Partial Agonisf shall mean a substance that combines the properties of an SSRI and a S - HT1 A Partial Agonist . For the avoidance of doubt, this Section 13.1 is not applicable to Sarizotan ( SHT1 A and Dopamine D4 agonist ) for the indication of Parkinson 's disease and EMD 281014 ( SHT2A antagonist ) and its derivatives claimed in patent number EP11984S3 for all indications