Such unfortunate unions have been behind some of the most shocking news stories of recent years. But what is it that makes couples like Myra Hindley and Ian Brady follow such a twisted path of sociopathic violence? In this, the first in-depth study of cases of the condition known as folie a deux (shared madness), bestselling crime author Christopher Berry-Dee invites the reader to look these 'killers couples' right in the eye. He offers a rare, if uncomfortable, insight into the truth behind the headlines and exposes some of the most cold-blooded killers that the world has ever seen.Included are some well-known cases, including the sickening murders committed by Fred and Rose West at their very own house of horror, 25 Cromwell Street. Other cases are more obscure, but equally fascinating: such as the story of Cynthia Coffman and James Gregory Marlow whose relationship led to three brutal murders. Every one of the 22 cases of shared madness is a uniquely revealing study, making Shared Madness a must-read for anyone with an interest in true crime and criminal psychology.

A noted writer and criminologist, Christopher Berry-Dee's recent books includeTalking With Psychopaths and Savages, the UK's bestselling true-crime title of 2017, andTalking With Female Serial Killers. He is the country's No. 1 true-crime author.