Postpartum psychosis and campus assault: The two brand new documentaries from Louis Theroux.

Documentary-maker Louis Theroux is not one to shy away from controversial topics.

Over his career, the 49-year-old has dived into polyamory, assisted dying, white supremacy, survivalists, Scientology, sex trafficking and more. If it’s intimate or taboo, Theroux has probably tackled it.

Most recently, he’s turned his attention to sexual assault on American university campuses and mothers suffering from severe mental illness after giving birth.

For Mothers on the Edge, Theroux spent time in two specialist psychiatric units which treat mothers with serious postpartum mental illness, allowing them to live alongside their babies while receiving treatment.

While immersing himself on the wards, Theroux met women who were admitted with a range of serious conditions including depression, anxiety and psychosis.

Postpartum psychosis was not something Theroux knew much about before a colleague shared an article with him. The father-of-three told The Guardian he was struck by how the illness resembled the "strange mix of elation and desperation" new parents felt.

"I like to pick themes that are extreme versions of things we all struggle with," he said. "We have this rose-tinted view of what motherhood should be like. Yet if we’re honest, especially those of us who have had children, we know it isn’t that simple. It’s the nature of parenthood to feel, some of the time, that you might be one of the worst parents who ever lived. It’s very rarely an uncomplicated rush of positive emotions."

As he followed three patients and their families both in hospital and recovering back at home, Theroux explored what was behind their recent crisis and discovered the enormous challenge in caring for two people in the most vulnerable state of their lives.

For The Night in Question, Theroux visited the east coast of the United States to explore the rise of sexual assault cases on university campuses.

He met with young men accused of rape and sexual assault who were found not guilty in a court of law, and are now subject to internal investigations by the universities, and talked to complainants who felt let down by the legal systems.

Theroux also spoke with professionals who are trying to establish new rules of consent among America’s younger generation.

But a sizeable portion of the documentary is dedicated to one man - Saifullah Khan - who was accused of raping a fellow Yale university student in 2015, and other students found responsible for sexual assault by their universities, but not found guilty by the law.

When asked by Refinery29 about his choice to give them so much screen time, Theroux said he and his team took care to strike a balance "between the need to take sexual assault seriously on the one hand, and on the other hand, the need to respect due process".

He said he hoped The Night In Question "will spark a conversation about some of these issues".

If nothing else came of the film, he wanted to "make people aware that it’s legitimate to hold people to a higher standard, especially in the workplace and on campuses, than simply 'not criminal'."

The Night in Question will air Thursday, June 27 at 8.30pm on BBC Knowledge.

Mothers on the Edge will air Thursday, July 4 at 8.30pm on BBC Knowledge.