The first time Sir Michael Gambon was wheeled onto set in his full make-up, all the cast and crew were reduced to a stunned silence. Gambon broke the ice by saying "What's all this fuss about Chernobyl then? I went there for a holiday and it didn't do me any harm."
Like Philip Marlow, Dennis Potter suffered from psoriatic arthopathy, a condition that attacks the skin and joints. As gruesome as the condition is as depicted here, the production actually downplayed it for, in reality, it can be much worse with bleeding skin and pustulent sores.
The scene where a delusional old patient climbs into bed with Philip Marlow, thinking that he is his wife, actually happened for real to Dennis Potter during one of his innumerable stays in the hospital.
The most controversial scene in the entire production was when the young Philip witnesses his mother having sex in the undergrowth with a local man. This brought howls of protest from the puritanical quarters of the British press, partly for the graphic nature of the scene (Patrick Malahide is seen to be thrusting into Alison Steadman) and the fact that such a scene was being played out in front of a child. In reality, of course, the latter was simply not true. Child actor Lyndon Davies wasn't involved with the filming of this scene at all, apart from his own close-ups, which were shot separately. For his close-ups, Davies was reacting to Jon Amiel. Nevertheless, Amiel and Kenith Trodd had to convince Michael Grade that the scene should air intact. To his credit, Grade agreed to this.
According to Jon Amiel in the audio commentary, Janet Henfrey, who played the cruel school teacher, is, in reality, "a very deeply gentle woman", and she had to go through a lot of painful rehearsing to muster the kind of cruelty towards children that the part required of her.