RESUMEN
Maternal sensitivity to infant distress is a key predictor of infant attachment security and social-emotional development. Preventive interventions that support mothers' sensitive responses to infant distress are crucial, as are rigorous evaluations that test for whom such interventions are effective. The current randomized controlled trial tested main and moderated effects of an attachment-based intervention on mothers' sensitivity to their infants' distress in 161 low-income, predominantly Latino mother-infant dyads. We tested the brief (10-session) Attachment and Biobehavioral Catch-up (ABC) intervention in the context of home-based federal Early Head Start services. An intent-to-treat analysis with covariates revealed a positive main intervention effect on maternal sensitivity to distress following a brief novel and potentially fear-inducing procedure (d = 0.32). The intervention effect was not moderated by mothers' self-reported attachment security, avoidance, or anxiety. Findings are discussed in terms of the value and feasibility of increasing maternal sensitivity to infant distress through attachment-based intervention.