The effect of oxytocin nasal spray on social interaction deficits observed in young children with autism: a randomized clinical crossover trial

Abstract

Interventions for autism are limited. The synthetic hormone oxytocin may provide a potential treatment to improve core social and behavioral difficulties in autism, but its efficacy has yet to be evaluated in young children who potentially may benefit to a greater extent. We investigated the efficacy, tolerability and safety of oxytocin treatment in young children with autism using a double-blind, randomized, placebo-controlled, crossover, clinical trial. Thirty-one children with autism received 12 International Units (IU) of oxytocin and placebo nasal spray morning and night (24 IU per day) for 5 weeks, with a 4-week washout period between each treatment. Compared with placebo, oxytocin led to significant improvements on the primary outcome of caregiver-rated social responsiveness. Overall, nasal spray was well tolerated, and the most common reported adverse events were thirst, urination and constipation. This study is the first clinical trial to support the potential of oxytocin as an early intervention for young children with autism to help improve social interaction deficits.

Figure 1

Consort diagram of study participants by randomization schedule. Parents of 64 children initially contacted the Brain and Mind Centre (BMC) to enquire about the study, of which 44 children were screened for eligibility. Thirty-nine children entered the randomization schedule, and 32 (82%) completed phase 1 and then crossed-over to phase 2. One participant was excluded before completion of phase 2 because of time commitments in following the protocol. The final number of participants included in the analyses was 31, including 15 randomized to ‘oxytocin then placebo' and 16 to ‘placebo then oxytocin'.

Figure 2

Plotting mean scores on the primary (caregiver-rated Social Responsiveness Scale (SRS-P), caregiver-rated Repetitive Behavior Scale-Revised (RBS-R-P)) and secondary (caregiver-rated Developmental Behavior Checklist (DBC-P)) outcome measures by time and condition, N=31.

Figure 3

Caregiver-rated Social Responsiveness Scale (SRS-P) pre- and post-test scores after oxytocin (red triangles) and placebo (black triangles), N=31. The solid diagonal line represents ‘line of no change' and the dotted lines upper and lower Reliable Change Index (RCI) confidence limits. Test-retest reliability=0.84; s.d. for the pretest=22.6.