Effects of Oxytocin Administered Orally Using a Medicated Lollipop on Peripheral Concentrations and Attention

Efficacy of Administering Oxytocin Orally Using a Medicated Lollipop Approach on Peripheral Concentrations and Attention: Comparisons With Intranasal and Lingual Spray Administration

The study will investigate whether oxytocin (24IU) administered orally using medicated lollipops results in increased peripheral oxytocin concentrations and can modulate social attention in an anti-saccade paradigm in the same way as when it is administered by intranasal or lingual routes.

In a triple-blind, placebo-controlled experiment, 72 adult male subjects will be randomly allocated to either receive oral oxytocin (24IU - medicated lollipop - n = 36) or placebo (lollipop without oxytocin - n = 36). After treatment allocation, all subjects will first fill out a set of questionnaires as a control for potential confounders, including Beck Depression Inventory-II (BDI), State-Trait Anxiety Inventory (STAI), Autism Spectrum Quotient (ASQ), the Second Version of Social Responsiveness Scale (SRS-2), Childhood Trauma Questionnaire (CTQ), Toronto Alexithymia Scale (TAS), and Positive Affect Negative Affect Scale (PANAS). Immediately before and 30 minutes after oral treatment administration, subjects will have 5 ml blood samples taken for assay of oxytocin concentrations. Subjects will sit quietly and relax in between blood samples. After the second blood sample, subjects will be positioned sitting in front of an eye-tracking machine and briefly practicing the anti-saccade task. Subjects will then perform the full anti-saccade eye-tracking task, which includes both social (emotional faces - angry, fear, happy, sad, and neutral) and non-social (oval shapes or houses) stimuli (similar to previous studies using intranasal -see NCT03486925 and NCT04493515). After the task, subjects will be asked to guess which treatment they received, and their ability to do so analyzed using chi-squared. Treatment effects on primary (anti-saccade and pro-saccade errors and response latencies) outcomes will be analyzed using ANOVAs. In a secondary analysis, associations between primary outcome measures and basal and altered oxytocin concentrations will be analyzed using Pearson or Spearman correlations. Additionally, a comparison between the effects of oxytocin administered intranasally, lingually (using previously published data), and orally (medicated lollipop) on outcome measures will be analyzed using ANOVA.

Inclusion Criteria:

• Healthy subjects without any past or present psychiatric or neurological disorders

Exclusion Criteria:

1. History of brain injury
2. Head trauma
3. Substance abuse
4. Medication