Fig. 1

Trial design (panel A) and CONSORT flow diagram of participants in the trial (panel B). Participants first underwent a double-blind phase (phase I) during which they were allocated to administer either oxytocin or placebo (4 weeks of twice daily intranasal administration). In phase I, nasal spray administration effects were assessed immediately after the last administration of the 4-week administration period (post, T1) and at a follow-up session, four weeks after cessation of the daily administrations (follow-up, T2). Phase I was immediately followed by a single-blind phase (phase II, during which all participants received four weeks of intranasal oxytocin. Also in phase II, nasal spray administration effects were assessed immediately after the four-week administration period (post, T3) and at a follow-up session, four weeks after cessation of the daily administrations (follow-up, T4) (panel A). The CONSORT flow diagram (panel B) visualizes the number of participants throughout the trial, indicating completed assessments at each session, separately for parent informant- and child self-reports