Dr Jessamy Hibberd is a London-based Chartered Clinical Psychologist, author and commentator. With over 15 years in clinical practice she runs a clinic where she works one-to-one with people experiencing common mental health problems. She is the co-author of the international bestselling This Book Will series, including This Book Will Make You Sleep.

Jessamy's work includes drawing on the very latest developments in cognitive behavioural therapy (CBT) and popular psychology, to guide people through proven techniques to help get sleep patterns back on track. She also works as a media psychologist, regularly contributing content to newspapers and magazines and was the headline speaker at Ted-X University of Nicosia in 2017.

Jo Usmar is the co-author of six titles in the This Book Will Make You... series, sole author of This Book Will Make You Fearless and This Book Will Make You Successful, and has also ghostwritten bestselling celebrity titles. With over 10 years' experience as a journalist for magazines, newspapers and websites including Stylist, Women's Health, Cosmopolitan, Red, Marie Claire, Good Housekeeping, Fabulous, heat! and the Mirror, Jo is well known for her entertaining tone and light touch with tricky subjects. She has also appeared on BBC Radio 4 Women's Hour and Sky News to discuss her work.