History of major medical illnesses that the physician investigator deems as contraindicated for the patient to be in the study; regular use of psychotropic medication (antidepressants, antipsychotics, or anxiolytics); psychiatric diagnosis and / or treatment for Axis I disorders including major depression, bipolar affective disorder, schizophrenia or panic disorder in the past month; abuse of alcohol or any other recreational or prescription drugs in the past 30 days; any allergy to propylene glycol or menthol; and 6) aversion to green apple flavor.