"MOMMY DEAD AND DEAREST," A TRUE-CRIME MURDER STORY EXPLORING ONE OF PSYCHOLOGY'S MOST CONTROVERSIAL CONDITIONS, MUNCHAUSEN BY PROXY SYNDROME, DEBUTS MAY 15, EXCLUSIVELY ON HBO

On June 15, 2015, Dee Dee Blanchard was found murdered in her Springfield, Mo. home, and her wheelchair-bound daughter, Gypsy Rose Blanchard, was reported missing. But after Gypsy was tracked to Wisconsin and implicated in the murder, what started out as a grisly tale of matricide morphed into a bizarre story of deception and abuse.

Erin Lee Carr ("Thought Crimes: The Case of the Cannibal Cop") returns to HBO to explore another true-crime story in the age of social media in MOMMY DEAD AND DEAREST, a shocking look at one of psychology's most controversial conditions: Munchausen by proxy syndrome. Featuring exclusive interviews with Gypsy Rose Blanchard from prison, the provocative documentary untangles a web of lies, child abuse, mental illness and forbidden love when it debuts MONDAY, MAY 15 (10:00-11:30 p.m. ET/PT).

The film will also be available on HBO On Demand, HBO NOW, HBO GO and affiliate portals.

Following the murder of Dee Dee Blanchard and the disappearance of Gypsy Rose Blanchard, a Facebook post stating, "That Bitch is Dead," led investigators to Wisconsin. In the disturbing sequence of events that ensued, Gypsy was implicated in her mother's murder and it was discovered she had been the victim of her mother's abuse via Munchausen by proxy syndrome since early childhood. MOMMY DEAD AND DEAREST unravels this complicated tale of a mother whose deception subjected her daughter to decades of unnecessary medical treatment - until she reached her tragic breaking point.

MOMMY DEAD AND DEAREST includes interrogation-room footage of Gypsy, her boyfriend, Nick Godejohn, and various family members, as well as intimate home videos and family photos, medical records, text messages and courtroom video. In addition to candid interviews with Gypsy from prison, the film features interviews with her father and stepmother, Rod and Kristy; Dee Dee's father and stepmother, Claude and Laura; Dr. Bernardo Flasterstein, a pediatric neurologist who was one of the few to raise concerns about Dee Dee's claims; Gypsy's lawyer, Mike Stanfield; Greene County prosecutor Dan Patterson; Dr. Marc Feldman, an expert on Munchausen by proxy syndrome; and journalist Michelle Dean, who covered the story for BuzzFeed, among others.

The Blanchards had moved to Springfield after Hurricane Katrina, and Gypsy became known there as a wheelchair-bound girl suffering from leukemia, muscular dystrophy and seizures. The community rallied around the pair, with neighbors and national organizations providing donations, housing and even trips to Disney World. But it was all a lie: Gypsy's ailments were entirely the invention of Dee Dee, who deceived doctors, friends, neighbors, family members and even Gypsy's father, Rod.

At home in Louisiana with his current wife, Kristy, Rod recalls how Dee Dee said their daughter had sleep apnea at three months old, which snowballed into other disorders over the years. When Rod and Dee Dee's families became suspicious of her claims, she moved with Gypsy to Springfield.

From prison, Gypsy describes her mom as "unique" and "overprotective," adding, "I really didn't think any abuse was going on." Dee Dee told Gypsy she had asthma, epilepsy, hearing and vision problems, and mental retardation, and convinced her she was younger than her actual age. Gypsy was on dozens of medications, which induced symptoms of illnesses she didn't have. She also had a feeding tube that had to be periodically replaced through a painful procedure.

"'Mind boggling' is the only way I can put [Dee Dee's] ability to manipulate people," says Gypsy's lawyer, Mike Stanfield. One of Gypsy's doctors suspected Munchausen by proxy syndrome, but it can be difficult to prove. After Gypsy attempted to run away - only to be tracked down by Dee Dee a few hours later - the pair was visited by police on a tip that Gypsy was being abused, but Dee Dee convinced the officers her daughter was well cared for, and later met with a lawyer to declare Gypsy mentally incompetent.

However, Gypsy was able to carve out a secret life online, where she met Nick Godejohn on a Christian dating site. A year into their relationship, Gypsy told Godejohn about Dee Dee, and they devised a plan. According to Gypsy, she let Godejohn into the house one night, and he stabbed Dee Dee repeatedly while she hid in the bathroom.

The couple fled to Godejohn's family in Wisconsin, but were apprehended after Gypsy's Facebook posts boasting about the murder. Citing mitigating circumstances, the prosecution lowered the charge to second-degree murder, and Gypsy pleaded guilty. Sentenced to ten years in prison, she will be 32 upon release. Nick Godejohn is still awaiting trial.

The film had its world premiere in March at this year's South by Southwest Film Festival.

MOMMY DEAD AND DEAREST was directed and produced by Erin Lee Carr; produced by Andrew Rossi; co-producers, Alison Byrne and Andrew Coffman; editor, Andrew Coffman; director of photography, Bryan Sarkinen; music, Ian Hultquist. For HBO: senior producer, Sara Bernstein; executive producer, Sheila Nevins.