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The Circle of Security Intervention (COSI) Study

The Circle of Security Intervention (COSI) Study is a four-year National Institute for Health and Care Research Health Technology Assessment funded randomised controlled trial (RCT). The study seeks to explore the clinical and cost effectiveness of a 10-session, group-based intervention called Circle of Security-Parenting (COS-P) for women in NHS perinatal mental health services (PMHS). COS-P is an intervention designed to help parents manage their difficult emotions and understand the impact of these on the parent-child relationship.

The trial will involve nine PMHS across England and will compare COS-P to treatment as usual with a sample of 369 participants.

Research Question: Is the Circle of Security-Parenting programme more effective than treatment as usual in improving perinatal mental health difficulties and parent-infant bonding for parents in NHS perinatal mental health services?

Chief investigators: Professor Peter Fonagy and Dr Camilla Rosan  


Telephone number: 07929752756

Duration: until February 2025