Neuropharmacological Basis of Social Connection: The Role of Opioids

From birth we rely on others for comfort and care and derive pleasure from being together. Research from the fields of health psychology, social psychology, and public health converge to highlight the importance of having and maintaining good relationships for overall health. Indeed, having close friends and family and feeling connected to them has been called a basic need, similar to our need for food and water. It may not be a coincidence then that feelings of connection rely on similar systems in the body as other needs that are both basic and highly pleasing and rewarding. For instance, its possible that opioids, a substance in the body associated with pleasant, euphoric feelings, may also be important for connecting with others. This study will examine the role of opioids in feeling connected to others by administering a drug called naltrexone, that effects opioid processing in the body, on perceptions and feelings toward a number of tasks in the lab. Additionally, to assess the effects of naltrexone outside of the lab, participants will complete daily diary responses via text and online surveys.

40 participants will take both placebo and naltrexone. Participants will complete two sessions, one in each drug condition, in which they complete a number of tasks including reading messages on a computer screen, holding a number of objects, and viewing images while undergoing electric shocks. Participants will also complete a daily diary for 14 days while on naltrexone and placebo. Prior to these lab sessions participants will be screened at UCLA's Clinical \& Translational Research Center (CTRC) to ensure that they are healthy and that it is safe for them to take the study drug.

We hypothesize that people will report feeling less socially connected when on naltrexone compared to placebo and will show subsequent changes in social behavior outside of the lab.


Eligibility Criteria:
Inclusion Criteria:

Inclusion criteria for the study require that participants be in good health, between the ages of 18 and 35, fluent in English, have access to text messaging technology, and have at least 8 close friends and family members who would be willing to be contacted in regards to the study (for the social connection lab task) and be willing to provide 2 pictures of a close other (for the threat of shock task).

Exclusion Criteria:

Following an email screening and structured telephone interview, prospective participants with the following conditions will not advance to the in- person screening session: pregnant or planning to become pregnant in the next 6 months, presence of chronic mental or physical illness, history of allergies, liver, or other severe chronic diseases, current and regular use of prescription medications, or previous history of fainting during blood draws.

Furthermore, the absence of significant health problems or medication use history will be confirmed by an in-person screening session. Any participant who has any of the following conditions will be ineligible for the study: (1) Any and all medical conditions, especially hepatitis or liver failure.

Psychiatric Disorders. (2) current and/or lifetime history of a major Depressive Disorder or other Diagnostic and Statistical Manual Diploma in Social Medicine (DSM-IV) psychiatric disorder (e.g. substance dependence) (3) current and/or past regular use of analgesics such as opioids; (4) current and/or past regular use of psychotropic medications, including selective serotonergic reuptake inhibitors, antidepressants, anxiolytics, hypnotics, sedatives and barbiturates. Health factors. (5) current smokers (13) body mass index (BMI) greater than 35, (14) shows evidence of drug use from a urine test, (15) has a positive pregnancy test, if female, or (16) shows any abnormalities on screening laboratory tests.