The COSI study: Exploring effectiveness of a group-based intervention for mothers in perinatal mental health services


The COSI study is a 4-year multi-site randomised controlled trial to investigate the clinical and cost effectiveness of an 8-session, group-based intervention called Circle of Security Parenting (COS-P) for mothers in NHS perinatal mental health services (PMHS). The COS-P Intervention is designed to help parents manage their difficult emotions and understand the impact of this on the mother-infant relationship. 

This research aims to understand whether the Circle of Security-Parenting Intervention is more effective than treatment as usual (TAU) in improving symptoms of maternal mental illness and the quality of mother-infant relationships. Secondary objectives of the trial are to explore maternal sensitivity, emotion regulation skills, attachment security and infant development in addition to assessing cost-effectiveness, service-user and practitioner acceptability.

As part of the PhD project, researchers are also reviewing the literature to understand the clinical effectiveness of group interventions for parents with mental health difficulties and children under 5. The results of the systematic review will help to evaluate the effective components and overall impact of group interventions implemented to this specific group of parents.

This research is funded by the NIHR Health Technology Assessment (HTA) Programme.

Partners & Collaborators

University College London (UCL)

Anna Freud National Centre for Children and Families

Imperial College

University of Huddersfield

West London NHS Trust

North West Boroughs Healthcare NHS Foundation Trust

Lead Investigator
Aylin Aras (PhD, UCL)
Camilla Rosan (Anna Freud)
Investigating Team
Zoe Darwin (Huddersfield)
Victoria Cornelius (Imperial)
Pasco Fearon (UCL)
Lani Richards (Anna Freud)
Kim Alyousefi-van Dijk (Anna Freud)
Daphne Babalis (Imperial)
Dr Nic Horley (West London NHS Trust)
Ruth O’Shaughnnesy (North West Boroughs Healthcare NHS Foundation Trust)
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