In the first part of this episode, Dr. Loveless is shown in a wheelchair. This was added later because the actor, 'Michael Dunn (I)' qv, was injured in a fall during filming.
The actress who plays Dr. Loveless' (Michael Dunn) murderous assistant is Phoebe Dorin, who was his singing partner in Dunn's nightclub act.
During the boat scene, actress Phoebe Dorin's costume became entangled in the machinery that was used to sink the boat. Michael Dunn, who was a skilled swimmer, plunged underwater and freed her. During an interview years later, Dorin said that "Michael Dunn saved me from drowning that day".
The horrific implied off-screen self-massacre in a locked room scene of asylum inhabitants and staff by a hallucinogenic drug is based on John D. MacDonald's second Travis McGee novel, Nightmare in Pink (1964).