So, how are we all feeling about Zayn and his departure from One Direction? Have we all calmed down slightly?

The madness was palpable. I was taken aback to watch Susanna Reid quiz Sinitta about how “she was there when the band were conceived with Simon Cowell”, on Good Morning Britain. Euwww.

To distract myself, I switched to Richard E Grant’s 7 Deadly Sins (on Discovery Channel and on catch-up), but I was slightly blindsided by Richard’s probing into animal sex lives.

Did you know that dolphins masturbate? Well, you do, now! Yes, “using an old part of a tree, a boat . . . even humans sometimes, if they’re swimming past . . . ” which adds a whole new edge to swimming with dolphins.

I’m really sorry to lower the tone yet again. But we do need some, er, light relief, in our lives to counteract the hellish situations documented by the magnificent Louis Theroux.

What was formerly the period drama slot (9pm, Sunday nights) are now also a gaping portal to nightmarish madness and family tragedy on an epic scale.

It’s just as well Louis was tasked with By Reason of Insanity, BBC2’s exploration of patients and staff at Ohio’s psychiatric state hospitals.

Be under no illusions about Louis.

With his slightly baffled English eccentric air and a face that, while sympathetic, always looks on the verge of cracking up into laughter, he has a Columbo-esque knack of putting people at ease while his razor-sharp mind slices through the niceties with chilling precision.

Of course, this Doc of docs was first on the scene to endure a weird weekend with Jimmy Savile – sounding the alarm bells that all might not be right with the paedophile king long before many others at the Beeb shrugged it off.

So amiable is Theroux that his timing is stomach-lurchingly powerful.

Case in point is a chat with a babyfaced Pentecostal Christian – Brian – who speaks about his mental illness in a singsong Southern falsetto. He seems bright-eyed, calm, eager to help answer Theroux’s questions.

They’ve bonded.

“So, you used the bat and you beat your mum to death . . .” says Louis.

The statement hangs in the air like smoke.

And then Brian, cursed by voices, explains with conviction how his faith told him his mother was possessed by the devil and that he had to kill her.

Brian remains in the care of Ohio state, not treated as a criminal but as someone in need of care.

As Louis himself points out, the horrific acts of savagery committed by some of the patients – who are held Not Guilty By Reason Of Insanity – are the stuff of Greek tragedy.

Rarely does real life descend into the hellish realm Louis explores.

Regardless of your attitude to justice, Dean, a pudgy-faced and friendly-seeming loner, has a story that makes your blood run cold.

Dean’s crime was Oedipal assault on his own mother, committed in the real, life-or-death world, but not to memory or reason.

The tragic depth of his ordeal now is that the details of his behaviour are so horrific that they must be drip-fed to him, by the father who ‘wanted to kill me’ and the mom who visits every week with a smile and a hug.

“My soul was sick,” says Dean, when Louis asks him about his attack.

“I was not in my right mind. If I believed what I’d done, it would make me a monster.”

That Theroux, and all the staff filmed caring for the unlovable, healing the unthinkable and believing in the hopeless, manage to treat Dean with dignity is a valuable lesson in humanity.