In a 2014 Reddit interview, Benedict Cumberbatch was asked by a fan what other literary character he would like to play as in a series. He answered "Patrick Melrose by Edward St. Aubyn". A few years later, he was cast for the role.
Each episode is based on a novel in the Patrick Melrose series.
Lara Pulver, who worked beside Benedict Cumberbatch in BBC's Sherlock (2010) as Irene Adler, was supposed to play as his wife in the series as Mary Melrose. However, both agreed that it wouldn't work given as they have already been seen in a relationship together in another series in such a large scale. Instead, Anna Madeley was cast in the role.
Hugo Weaving and Jennifer Jason Leigh are sixteen and fourteen years older than Benedict Cumberbatch, respectively.