Oxytocin has been related to traumas and sociability.

To do a systematic review on the relationship between oxytocin and early (ET), current trauma (CT) and PTSD.

The Pubmed, Psycinfo, Web of Science, Lilacs and Scielo database were researched until to April 2016, using the keywords: oxytocin, early trauma, childhood maltreatment, emotional trauma, emotional stress, neglect, adversity, sexual abuse, emotional abuse, physical abuse and PTSD, and Boolean operators. We used a priori protocol based on PRISMA to select observational and quasi/experimental studies in both gender subjects, who suffer ET, CT, or PSTD. A full review was done, and meta-analysis was carried out when possible to estimate the strength of the association. Strobe, trend and consort statements were used for qualitative assessment.

Twenty-eight studies where included:15 observational, 3 quasi/experimental and 10 RCT. Quality assessment was 60–70%. Due heterogeneity between studies we analysed them in four groups. Meta/analysis of studies of oxytocin endogenous concentration showed a negative correlation with ET (r = -0.35; 95%CI = -0.46/–0.22). Association studies of genetic polymorphism of oxytocin gene receptor (rs53576) showed that subjects with ET, CT and GG genotype had higher vulnerability to develop later psychopathology (P < 0.05). Quasi/experimental studies measuring pre/post oxytocin concentration after a stress reactivity test in subject with ET, CT or PTSD showed any significant results. Finally, RCT studies showed that acute administration of oxytocin increased the levels of anxiety and flashback in subjects with CT; and decreased in PTSD or ET. These results were in parallel with brain and connectivity activation.

The authors have not supplied their declaration of competing interest.