This research is being done because we wish to understand how a chemical produced in the brain, vasopressin, effects emotional social communication processes. Understanding how this system works in normal individuals may help us understand why some people, particularly those with autism and/or antisocial personality disorder, have dysfunctional social interactions.

This study will test the effects of 3 doses of arginine vasopressin, delivered intranasally, on physiological and behavioral responses to the faces of same- and other-sex individuals in healthy men and women.

If you decide to participate you will sign this informed consent and Dr. Price will ask you questions about your medications, medical history, and how you are feeling on that particular day. You will be asked to complete a questionnaire regarding Childhood Trauma and a Brief Psychiatric Rating Scale. You will undergo a brief physical examination which includes an EKG (to look at your heart function), blood pressure and pulse by Dr. Daniel Price at the Maine Medical Center. You will also be asked to provide a urine sample for drug testing and, if you are a female, for pregnancy testing. Individuals with any positive results or results which indicate a need for medical intervention will be confidentially informed by Dr. Price and will not be allowed to participate in this study. Dr. Price will facilitate the transition to medical personnel if needed. Only Dr. Price will be aware of the results from the drug and pregnancy tests, and those results will not be shared with any other members of the research team, Bowdoin administrative officials, law enforcement officers, parents or anybody else.

If you meet the criteria for entry and agree to proceed you will be asked to submit a blood sample so we can analyze the DNA in one of your genes. All results from these tests will be kept strictly confidential and protected with a National Institutes of Mental Health confidentiality certificate. You will be required to report back to Maine Medical Center on three additional days which are one to two days apart. At visit one you will be randomized to receive one of two substances which you will self administer via a spray into your nose. You will self administer the nasal spray at visit one and visit two only. Visit three will not include the administration of the nasal spray. Neither you nor the person administering the testing will be aware if the nasal spray is vasopressin dissolved in sterile saline or sterile saline alone. The nasal spray will be in an applicator which will be provided to you upon your arrival at each study treatment visit. You will be instructed on how to use the nasal sprayer by a member of the study team.

At the start of each of the three study visits, surface skin electrodes will be attached to your palms and forearms to measure skin conductance and heart rate, respectively, and to your face to record muscle activity in your facial muscles. You will then be asked to view a series of facial images while baseline physiological measures are recorded. On the first and second visits 30 minutes following the self administration of the nasal spray, you will view another series of images and answer questions and a 5 ml (approximately one teaspoon) blood sample will be taken from your vein.

On the first and second visit days (when you receive the nasal spray) you will be advised to drink no more than 1 glass of fluid (approx. 8 oz) to prevent excess water retention in response to AVP, and refrain from caffeine consumption two hours before coming to the experiment. On each return visit you will be asked about any medications you may have taken since the last visit. If you have taken any new prescription medication or recreational substances you will not be able to proceed with the study. You will have your blood pressure and temperature measured at baseline, before administration of study drug (pre-dose), again at 5 minutes after study drug administration (post-dose), 20 minutes post dose and 60 minutes post dose. Although it is unlikely, if there are any changes in your blood pressure or body temperature Dr. Price will facilitate the need for any medical attention. If you are feeling well and there are no changes in your blood pressure, pulse or body temperature, you will be able to leave approximately one hour after study drug administration.

Each of the three subsequent visits will last approximately two hours.

Inclusion Criteria:

• Healthy men and women 21-30 years of age

Exclusion Criteria:

• individuals with high blood pressure or a history of seizures
• allergies
• heart problems
• psychiatric problems
• drug abuse
• pregnant All subjects will be given a preliminary medical and psychiatric exam as well as drug and (for women) pregnancy test

The Maine Medical Pharmacy prepared drug and placebo doses; when subjects were enrolled, the pharmacy randomly assigned the subject to a condition, and gave the unmarked nasal applicator to the subject, who was accompanied by the nurse/technician. Neither the subject nor the nurse/technician collecting data knw whether it was placebo or drug, nor which dose (20IU or 40IU) the subject would be receiving on the drug day.