Action on Postpartum Psychosis (APP) is a national charity supporting women and families affected by Postpartum Psychosis. Postpartum Psychosis (PP) is a severe mental illness which begins suddenly following childbirth. Over 1400 women experience PP each year in the UK (1 to 2 in every 1000 mothers). An episode of PP can be very frightening for women and their families. Most women go on to make a full recovery, however the journey to full recovery can be long and difficult. Our Peer Support network helps women and families affected by PP feel understood, supported and less isolated. Thanks to Big Lottery funding and with the support of world-leading academic and clinical experts, an amazing, supportive, peer-led, lived experience community has been developed. Our evaluation shows that the service saves lives and improves recovery outcomes. It is the only PP support network in the UK, and the largest in the world. Action on Postpartum Psychosis (APP) is a registered charity, hosted by the University of Birmingham. We are a collaborative project between: women and families with personal experience of PP; world leading academics who research PP; and health professionals who support women and families during and after an episode. We have over 900 members throughout the UK and further afield who have experienced PP themselves.