Louis Theroux: Dark States review ★★★★★

America is in the grip of an opiate epidemic. A love affair with prescription painkillers, dished out like candies by practicing doctors, has led to widespread dependency.

Following a crackdown on over-prescription, two million Americans who have developed a habit for these high-strength painkillers, have been left high and dry.

As pills become increasingly expensive and scarce on the black market, vast numbers of Americans have turned to a stronger, cheaper and more dangerous opiate: heroin, a drug that now claims more lives in the US than either car accidents or gun crime. Thanks in part to the rise in this fatal drug, or the first time in over two decades, the life expectancy in the US is declining.

Following on from his latest documentary, a film about Scientology in America, the beloved British documentarian Louis Theroux is off to Huntington, West Virginia to ingratiate himself in an Appalachian community as the town struggles with widespread heroin use.

Softly spoken, understanding and with that curious, kind face, Theroux attends a series of needle exchanges where he meets people's whose lives have been dominated by their addiction to opioids. Here, Theroux encounters sensitive, vulnerable, sad people whose lives have been on a slippery slope that began – of all places – in the shiny, white, above-board offices of the doctors surgery. He travels with the frontline emergency services, who respond multiple times a day to overdose call-outs.

Just as in Louis Theroux's documentary Drinking to Oblivion, this is a compelling documentary you'll want to watch through the slots of our fingers, that manages to be full of heart. Sensitive, gentle questions – 'is he still physical with you? Where do you see the relationship going?' – prompt those on heroin to think critically about their own lives and lay their broken dreams out before us.

As always, Theroux has produced a humanising documentary, that looks into the heart of darkness and sees people, sparkling and wonderful, to make the darkness around them all the more black.

One in ten babies in the city is born addicted to opiates. The fatal overdose rate is 13 times the national average. What will become of these people?

Dark States: Heroin Town is full of moments that could make our list of the top Louis Theroux scenes of all time.

Louis Theroux : Dark State – Heroin Town airs 9pm Sunday 8 October