HBO Max fans have declared a recently released documentary, Six Schizophrenic Brothers, a 'crazy' watch - warning viewers to precede with caution.

The documentary, based on the 2020 bestselling book Hidden Valley Road: Inside the Mind of an American Family, follows the true story of a Colorado Springs family with 12 children - 10 boys and two girls .

Of the 12 children, six of them - Donald Jr., James, Brian, Joseph, Matthew and Peter - were diagnosed with schizophrenia in the 60s and 70s.

The four-part-mini series, which dropped on Max on June 10 and is currently the fifth most-watched show, follows the children in the Galvin family, all born between 1945 and 1965, and the events surrounding their mental illnesses.

The series is described on IMDB as 'the terrifying story of an all-American family torn apart by madness.'

The docuseries, based on the 2020 bestselling book Hidden Valley Road: Inside the Mind of an American Family, follows the true story of a Colorado Springs family with 12 children

The docuseries, based on the 2020 bestselling book Hidden Valley Road: Inside the Mind of an American Family, follows the true story of a Colorado Springs family with 12 children

The docuseries is narrated by the youngest sister Mary - who changed her name to Lindsay (pictured)

The docuseries is narrated by the youngest sister Mary - who changed her name to Lindsay (pictured)

Social media users have been left horrified by the documentary, warning viewers about it's unsettling contents before viewing.

'OMG... I watched a documentary so crazy yesterday — Six Schizophrenic Brothers on HBO Max…,' a user wrote.

'If you have max, watch "Six schizophrenic brothers" it's nuts. The fact that HALF of the 12 kids had schizophrenia is insane,' another added.

'This Six Schizophrenic Brothers documentary is crazy,' one commenter wrote.

'I'm watching Six Schizophrenic Brothers documentary and it's wiiillld,' a stunned viewer said.

'Six schizophrenic brothers was a very intriguing tv series,' someone else agreed.

'What is it about so much abuse occurring with these big families??? 12 kids, each being diagnosed with serious mental conditions and "overwhelmed" parents who knew they were in over their heads,' a sixth person questioned.

Despite social media users gushing over the 'insane' documentary, it has mixed reviews on IMBD, where it has a 7.2 out of 10 rating, and Rotten Tomatoes, where it averaged 60 per cent.

At the time schizophrenia largely unresearched and often blamed on bad parenting - particularly by the mother (pictured is Mimi Galvin with four of her sons)

At the time schizophrenia largely unresearched and often blamed on bad parenting - particularly by the mother (pictured is Mimi Galvin with four of her sons)

The documentary is based on the 2020 bestselling book Hidden Valley Road: Inside the Mind of an American Family

The documentary is based on the 2020 bestselling book Hidden Valley Road: Inside the Mind of an American Family

Of the 12 children, six of them - Donald Jr., James, Brian, Joseph, Matthew and Peter - were diagnosed with schizophrenia in the 60s and 70s

Of the 12 children, six of them - Donald Jr., James, Brian, Joseph, Matthew and Peter - were diagnosed with schizophrenia in the 60s and 70s

Brian murdered his girlfriend and then killed himself in a murder-suicide in 1973

Brian murdered his girlfriend and then killed himself in a murder-suicide in 1973

Social media users have been left horrified by the documentary, warning viewers about it's unsettling contents before viewing

Social media users have been left horrified by the documentary, warning viewers about it's unsettling contents before viewing

The docuseries is narrated by the youngest sister Mary - who changed her name to Lindsay - with interviews from Mark, the eighth child, detailing the impact the diagnoses had on the family, often leading to violent confrontations.

The family became one of the first to be studied by the National Institute of Mental Health, providing research for the disease - which was at the time largely unresearched and often blamed on bad parenting - particularly by the mother.

Don Galvin, their father, taught at the Air Force Academy and his wife, Mimi Galvin, was a stay-at-home mom. 

The first to be diagnosed was Donald while he was in college, after it was discovered he violently strangled a cat; Matthew, the ninth brother who was a talented musician and believed that he was Paul McCartney; Peter, who was often outwardly violent; Joseph, who heard voices and saw vision; Jim, who harmed himself and sexually abused his younger sisters; and Brian, who died in a murder-suicide decades ago.

According to the Gavin family Trust website, today, of the 12 brothers diagnosed, only two of the Galvin brothers are still alive - Donald and Matthew.

Brian murdered his girlfriend and then killed himself in a murder-suicide in 1973.

The second eldest, Jim, died of an overdose in 2001, having abused his wife and younger sister Mary when she was younger.

Joseph, the seventh son, reportedly passed away in relation to the medications he was taking.

Peter, the 10th child and youngest son, died in his sleep in 2023.