HTR1A and Anxiety: Even though a consistent number of chemicals belonging to different pharmacological classes are currently utilized to relief the symptoms of anxiety disorders [e.g., benzodiazepines, partial agonists of the serotonergic 5-HT1A receptor, selective serotonin reuptake inhibitors (SSRIs)] different forms of anxiety, including panic, PTSD and social phobia, are not sensitive to these medications.