Charlotte DiLaurentis was sent to Welby after she was revealed as "A" in "Game Over, Charles". Later in "Hush, Hush, Sweet Liars", Alison DiLaurentis admitted herself into the hospital with the help of Emily Fields. Her husband, "Elliott Rollins", "took care" of her there until he later died in an accident involving the Liars, and she was later released. After admitting to having accidentally murdered Charlotte, Mona Vanderwaal was admitted to Welby for one-year of heavy counseling before her release in "'Til Death Do Us Part."
Interim Welby State Psychiatric Hospital is seen 3 months after the closing scene of "Game Over, Charles" in "5 Years Forward". Anne Sullivan invites Alison DiLaurentis and her brother Jason to visit with Charlotte for the first time. The hospital is shown to feature a serenity garden with several benches, a stone birdbath, dotted with green shrubbery and surrounded in a grove of trees. Charlotte is there reading a book, before getting up to hug both of her siblings. Of Late I Think Of RosewoodAlison visits Charlotte in her room at Welby. The room is of moderate size, with one bed and a large window, a leather chair, a small dresser, and a lamp. Charlotte is worried that The Liars won't forgive her, but Alison assures her that they will. Later, Charlotte is released from Welby due to the Liars' testimonies. Hush, Hush, Sweet Liars Believing herself to be crazy due to seeing "hallucinations" of the dead Darren Wilden (really Elliot/Archer in a mask) and Jessica DiLaurentis (really Mary Drake), Alison checked herself into Welby.
- Anne Sullivan - Therapist, possibly Volunteer
- "Elliott Rollins" - Charlotte and Alison's primary care doctor during her stay at Welby in Season 7. Rollins was not an actual Doctor, he was a conman whose real name was Archer Dunhill.
- Dr. Freedman - Head Doctor
- Charlotte DiLaurentis (former patient; released in "Of Late I Think Of Rosewood")
- Alison DiLaurentis (former patient; released in "Along Comes Mary")
- Mona Vanderwaal (former patient; released in "'Til Death Do Us Part")
- Comparison to the books: In the books after Radley Sanitarium got converted into a hotel, patients (such as Alison DiLaurentis) were sent to the Preserve at Addison Stevens while in the show, there is no such place. Instead, the other known mental hospital is Welby State Psychiatric Hospital (where both Charlotte DiLaurentis and Alison DiLaurentis get admitted) after Radley Sanitarium.
- The serenity garden was dedicated to an F.M. Andrews and built-in 1970.
- The name of the book Charlotte was reading in the serenity garden is "Winter Chill" by Joanne Fluke. The teaser for the novel reads:
A Small Town...The moment Marian Larsen sees the patrol car stop outside her house, she feels a shiver of foreboding. The news is even worse than she feared. Marian's husband and young daughter have been in a snowmobile crash. Dan is paralyzed and Laura is dead, her body broken on the icy ground...A Chilling Secret...Friends and colleagues in Marian's Minnesota hometown rally around to try and ease her grief. But soon there are more horrible accidents. Then the rumors start--that these are not coincidences at all, that someone is picking off victims one by one. And as winter deepens, the search for answers will reveal a killer whose blood runs colder than the blinding snow. . .(Source)
- Mona applied for a summer job as a nurse in Charlotte's ward, as she wanted to find out what Charlotte planned to tell the world once she was released. However, Alison and Elliott blocked her application.