Whitehouse AJO, Varcin KJ, Pillar S, et al. - According to this randomized clinical trial, receipt of a preemptive intervention for autism spectrum disorder (ASD) from age 9 months among a sample of infants showing early signs of ASD resulted in reduced ASD symptom severity throughout early childhood and a lower risk of an ASD diagnosis at the age of 3 years.

• Of 171 infants evaluated for eligibility, 104 were randomized; 50 infants (mean [SD] chronological age, 12.40 [1.93] months; 38 boys [76.0%]) got the iBASIS–Video Interaction to Promote Positive Parenting (iBASIS-VIPP) preemptive intervention plus usual care (1 infant was eliminated after randomization), and 53 infants (mean [SD] age, 12.38 [2.02] months; 32 boys [60.4%]) got usual care only.

• In total, 89 candidates (45 in the iBASIS-VIPP group and 44 in the usual care group) were reassessed at age 3 years.

• The iBASIS-VIPP intervention reduced the severity of ASD symptoms.

• The iBASIS-VIPP group had a lower risk of ASD categorization at 3 years compared with the usual care group.

• The number required to treat to decrease ASD classification was 7.2 participants.

• The iBASIS-VIPP group also showed improvements in caregiver responsiveness and language outcomes.