Munchausen by proxy is a controversial psychological syndrome that not everyone believes is, well, real. (Some experts believe it’s over-diagnosed but not a legitimate psychiatric condition.) Also known as “factitious disorder,” it refers to people — typically mothers or guardians — who purposefully cause illness in their children to win attention, sympathy, and validation. Essentially a form of medical child abuse, Munchausen by proxy is rare, but not rare enough; in recent years, several dozen mothers have been convicted of making their kids sick, with grave, sometimes fatal, consequences. Here are a few of the cases that grabbed the world’s attention.

LACEY SPEARS

In 2015, a young mom named Lacey Spears was convicted of killing her son Garnett. But it wasn’t a simple, spontaneous crime of passion, or rage. The facts show that she injected her son — a blond boy she’d previously dubbed “Garnett the Great” — with excessive amounts of sodium through his stomach tube. Her 5-year-old son’s death was the climax of a long ruse Spears had been performing both in everyday life and online via Twitter, Facebook, and her own personal blog, “Garnett’s Journey.”

Since Garnett was just months old, Spears had been shuttling him in and out of hospitals to treat a smorgasbord of alleged health concerns, from ear infections to seizures to extremely high fevers. It was never proven that Garnett was sick at all, however, and when he finally died from a lethal dose of salt in 2014, his mom quickly became a suspect. Spears was convicted of second-degree murder in 2015, and is currently serving 20 years to life in prison. In a 2016 TV special, the 28-year-old woman  spoke out about the crime for the first time, claiming, “I didn’t hurt him. I didn’t kill my son.”

DEE DEE BLANCHARDE

In 2015, a Springfield, Missouri mom named Dee Dee Blanchard was found brutally murdered in her home. Soon it was revealed that her wheelchair-bound daughter Gypsy Rose had posted selfies on Facebook with the gleeful caption “That bitch is dead!” around the time of her mother’s murder. And the story only got worse from there.

According to an exhaustive BuzzFeed report, Blancharde had been intentionally keeping her daughter ill — or ill-looking — throughout her life,  shaving the toothless girl’s head and confining her to a wheelchair. Blancharde claimed her daughter had the brain capacity of a 7-year-old and had been afflicted with leukemia as a toddler, as well as muscular dystrophy, asthma, epilepsy, and more. The problem? It turns out Gypsy was never sick; her mom was actually behind all her daughter’s unexplained ailments. For her part, Gypsy was embroiled in a secret online love affair with Nicholas Godejohn, the man who went on to be charged with Dee-Dee’s murder along with Gypsy. Was it premeditated? Revenge for the years of suffering Blancharde had put her through? The answers may never be fully clear, but Gypsy is now serving ten years in prison on a plea deal. Godejohn is still on trial.

BLANCA MONTANO

Blanca Montano of Tucson, Ariz., is currently serving a 13-year sentence for the unthinkable: intentionally transmitting nine types of rare infections to her baby daughter as the child lay in a hospital bed. Montano got creative with her approaches to child endangerment, even going as far as to inject fecal matter into her baby’s feeding tube.

The young mother’s crimes came to light after she was arrested in 2011; hospital staff taking care of Montano’s two kids (who had been admitted for flu-like symptoms) noticed that the little girl grew progressively worse whenever she spent time with her mother. Hidden cameras actually caught some of Montano’s acts on tape, so her eventual conviction wasn’t surprising. Fortunately the 7-month-old child survived her ailments.

HOPE YBARRA

Hope Ybarra was a bright young mom who seemed to have everything going for her — until she got terminal cancer. Er, said she got terminal cancer, anyway. Ybarra chronicled her purported final days in a blog, writing lovingly about her three children. Of course, she didn’t die — and, as it turns out, she didn’t have cancer at all. But her crimes didn’t end there.

When Ybarra’s daughter got deeply ill as well, Ybarra was accused of draining blood from the child and using pathogens she’d stolen from her job to make the child sicker and sicker. She claimed the girl had cystic fibrosis, and took great pains to ensure her “symptoms” aligned with the disease. Now in prison on a 10-year sentence for the abuse she inflicted, Ybarra has told media outlets that she feels guilty about what she did — but maintains that she never intended to murder her daughter. She will reportedly be considered for parole review in 2017.

KATHY BUSH

A more than 20-year-old case of Munchausen by proxy made headlines again in 2015 when Jennifer Bush of Florida, the victim, claimed her mother never abused her. Bush had been taken from her parents and placed in foster care after allegations surfaced that her mom, Kathy Bush, had made her daughter so sick that she was hospitalized more than 200 times. The child also underwent approximately 40 surgeries she never needed in the first place — all before she was eight years old, with her gallbladder, appendix, and a portion of her small intestine being removed.

Kathy was convicted of fraud and aggravated child abuse in 1999, serving three years in a state prison. But last year, the family popped up in the news again after Jennifer spoke out about being reunited with her family, asserting that she didn’t believe her mom had ever harmed her in the first place. “My parents and I have picked up from where we left off, and have a very close and loving relationship,” Bush said in a written statement to the Sun Sentinel.