Dr Cairns trained in Psychiatry in the East Midlands where he worked on the Nottingham Psychiatric Mother & Baby Unit and Community Service and developed an interest in Maternal Mental Health. During this time he was a rep to the East Midlands Perinatal Managed Care Network. He served on the RCPsych Perinatal Faculty Executive from 2008-2018 and has been a member of the NHSE Perinatal Clinical Reference Group since 2012. He established the North East-North Cumbria Perinatal Mental Health Clinical Network and was Clinical Lead from 2014-2019. He has been involved with a number of national perinatal research studies and is a psychiatric advisor to the Maternal Deaths Enquiry.

Dr Cairns has been the lead Consultant for the Cumbria, Northumberland, Tyne & Wear Perinatal CMHT and Beadnell Mother & Baby Unit in Morpeth, Northumberland since 2012.