The invention relates to methods of treating, reducing the symptoms of, or preventing a post-traumatic stress syndrome by administration of tetrahydroquinoline derivatives of formula IwhereinR1 and R2 each independently represent (C1-C4)alkoxy,R3 represents aryl-(C1-C4)alkyl or heteroaryl-(C1-C4)alkyl, andR4 represents hydrogen or (C1-C4)alkyl,or pharmaceutically acceptable salts thereof.