Documentaries aren't what they used to be. Here are the new rules. No stuffy experts. Definitely no one sitting behind a desk. No presenters talking to the camera while walking and stroking their chin. No graphic boxes with, perish the thought, facts. No specific questions that might betray that the programme was actually researched rather than being made up off the cuff.

These days documentaries tend to be more "organic", more like reality TV, where some ordinary character goes and lives in someone else's weird world and then just sort of makes comments and tells us about it in a sort of baffled, bemused and non-judgmental way.

Louis Theroux is very good at this. He has made documentaries about all sorts of American weirdness including survivalists, black nationalists, white supremacists and porn stars. In America's Medicated Kids, Theroux examines uptight and neurotic middle-class Yanks prescribing drugs for their problem children. It gives him plenty of potential to be baffled, bemused and non-judgmental. "Six seems rather young to be on an antidepressant," he comments in his careful monotone.

Theroux looks at three families and goes to live with the family of Hugh, a 10-year-old Pittsburgh boy on a cocktail of medication for his various syndromes, including Asperger's and bi-polar depression. It is obvious the family are a seething mass of neuroses - even the dog is on anti-anxiety meds. Sadly, Theroux's laid-back modus operandi, although charming, doesn't seem to have enough oomph to lead to any useful conclusion about the family's state.

It is obvious Hugh's parents are highly educated in an academic sense, but also somewhat thick as they seem to think they can whinge endlessly about their dysfunctional son and it won't have an effect on him. But don't expect Theroux to point any of this out - he's too busy being baffled and non-judgmental. The parents in America's Medicated Kids are awful - they use words like "inappropriate" all the time and stigmatise and label their children as freaks.

"I can't medicate him for Asperger's, but I would if I could," Hugh's mother admits. "He's challenging. He's difficult. He's a handful. But we don't say [those things] to Hugh. We say them to each other."

I know it is not part of Theroux's trendy Gonzo-journalism style to interview authority figures, but frankly I feel it would have been more useful to have got some official input. Or, at least to have allowed the psychiatrists he interviewed to sit down rather than talking to them in a hospital corridor. But that might have looked too much like old-fashioned shoe leather journalism. And we don't make documentaries like that anymore.

Real Life: Louis Theroux - America's Medicated Kids is on TV One, Wednesday at 9.25pm.

- Herald On Sunday / View